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Verified by IngredientMD/GNC/Mega Men Multivitamin
VERIFIED BYingredientMD

Mega Men Multivitamin.

Strong evidence, strong doseGNC, verified Oct 2026Formula verified. Independently reviewed.Independent review. Not commissioned by GNC.

Vitamin C is the lead active here, studied most for iron status. 20 human studies on Vitamin C back this formula, each one cited. Each serving carries 300 mg of Vitamin C, inside the range the published research used. Who it fits: made for men, adults.

Full label disclosure
40Active ingredientsWell studiedResearch base410Human studies
Mega Men MultivitaminVerified by IngredientMD
GNCIngredientMD
The verdict
Strong evidence, strong dose
For Made for men, adults.
How we verify

The brand submits the formula. We read the supplement facts panel and weigh dose, form and synergy against the clinical evidence. Labs test. IngredientMD verifies. The fee pays for review time, never for the outcome.

The formula
Vitamin A: Filling everyday nutrient gapsExtensively studied
Vitamin C: Iron statusKey driver
Vitamin D3: Filling everyday nutrient gapsExtensively studied
Vitamin E: Filling everyday nutrient gapsWell studied
Vitamin K: Filling everyday nutrient gapsExtensively studied
Thiamin (Vitamin B1): Filling everyday nutrient gapsExtensively studied
Riboflavin (Vitamin B2): Filling everyday nutrient gapsExtensively studied
Niacin: Filling everyday nutrient gapsWell studied
Vitamin B6: Filling everyday nutrient gapsSupporting role
Folic Acid: MethylationExtensively studied
Vitamin B12: Vitamin B12 statusExtensively studied
Biotin: Filling everyday nutrient gapsWell studied
Pantothenic Acid: Filling everyday nutrient gapsWell studied
Calcium: Filling everyday nutrient gapsExtensively studied
Iodine: Iodine statusExtensively studied
Magnesium: Magnesium statusExtensively studied
Zinc: Filling everyday nutrient gapsExtensively studied
Selenium: Filling everyday nutrient gapsExtensively studied
Copper: Filling everyday nutrient gapsWell studied
Manganese: Filling everyday nutrient gapsWell studied
Chromium: Filling everyday nutrient gapsWell studied
Molybdenum: Filling everyday nutrient gapsWell studied
Energy & Metabolism Blend: A 150 mg blend of five ingredients, listed by weight.Supporting role
Caffeine Anhydrous: Morning alertness. In the 150 mg Energy & Metabolism Blend with four others, listed first.Extensively studied
Green Tea Extract: Skin health. In the 150 mg Energy & Metabolism Blend with four others, listed second.Well studied
Eleuthero Root Powder: Energy without a stimulant. In the 150 mg Energy & Metabolism Blend with four others, listed third.Well studied
Capsicum Seed Extract: Temperature regulation. In the 150 mg Energy & Metabolism Blend with four others, listed fourth.Supporting role
Black Pepper Fruit Extract: Filling everyday nutrient gaps. In the 150 mg Energy & Metabolism Blend with four others, listed fifth.Well studied
Alpha-Lipoic Acid: Skin healthWell studied
Lutein: Skin healthExtensively studied
Lycopene: Skin healthWell studied
Turmeric Root Extract: Part of this formulaSupporting role
Zeaxanthin: Eyes under bright screen lightWell studied
Astaxanthin: Skin healthWell studied
Beta-Cryptoxanthin: Filling everyday nutrient gapsSupporting role
Choline: Choline statusExtensively studied
Inositol: Clearer skin through cycle changesExtensively studied
Silica: Hair healthSupporting role
Boron: Magnesium statusWell studied
Vanadium: Filling everyday nutrient gapsSupporting role

How we read this product

Source: Supplement facts
Supplement Facts panel for Mega Men Multivitamin
  1. 01
    We read the label.

    The panel on the left is the one we evaluated, line by line.

  2. 02
    Every active, separately.

    All 40 actives checked against the clinical evidence: dose, form, and what the research actually shows.

  3. 03
    Then the formula as a whole.

    Doses, ratios, and how the ingredients work together. That assessment is the verdict above: "Strong evidence, strong dose".

  4. 04
    Earned, not bought.

    The verdict is public and identical whether or not a brand pays. A formula that does not clear the bar gets nothing.

Read by the engine against 2.1 million data points from clinical trials, PubMed and more than a hundred vetted sources. No individual reviewer is named or implied.

The receipts

Well studied
Research base
410
Human studies
300 mg
Vitamin C
5000 iu
Vitamin A
300 mg per serving sits inside the studied 200 mg-500 mg range
Vitamin C, Levine 1996 pharmacokinetics + NIH ODS
50 mg per serving sits inside the studied 1 mg-50 mg range
Thiamin (Vitamin B1), NIH ODS + Lonsdale 2006 review
50 mg per serving clears the studied 1 mg minimum
Riboflavin (Vitamin B2), NIH ODS + Schoenen 1998
50 mg per serving sits inside the studied 20 mg-100 mg range
Niacin, NIH ODS + AIM-HIGH trial + HPS2-THRIVE

Cross-checked against 8,335 documented interactions for these actives.

Read the evidenceVitamin A, the evidence →Vitamin C, the evidence →Vitamin D3, the evidence →Vitamin E, the evidence →Vitamin K, the evidence →Thiamin (Vitamin B1), the evidence →

Inside the formula

Vitamin A
Filling everyday nutrient gaps
Extensively studied
Vitamin C
20 studies
Iron status
Studied 200 mg to 1 g a day
Key driver
Vitamin D3
20 studies
Filling everyday nutrient gaps
Extensively studied
Vitamin E
15 studies
Filling everyday nutrient gaps
Well studied
Vitamin K
11 studies
Filling everyday nutrient gaps
Extensively studied
Thiamin (Vitamin B1)
11 studies
Filling everyday nutrient gaps
Extensively studied
Riboflavin (Vitamin B2)
10 studies
Filling everyday nutrient gaps
Studied 1.3 mg to 100 mg a day
Extensively studied
Niacin
Filling everyday nutrient gaps
Studied 20 mg to 500 mg a day
Well studied
Vitamin B6
Filling everyday nutrient gaps
Supporting role
Folic Acid
14 studies
Methylation
Extensively studied
Vitamin B12
17 studies
Vitamin B12 status
Extensively studied
Biotin
Filling everyday nutrient gaps
Studied 30 mcg to 5 mg a day
Well studied
Pantothenic Acid
Filling everyday nutrient gaps
Studied 5 mg to 200 mg a day
Well studied
Calcium
13 studies
Filling everyday nutrient gaps
Extensively studied
Iodine
13 studies
Iodine status
Studied 150 mcg to 500 mcg a day
Extensively studied
Magnesium
21 studies
Magnesium status
Extensively studied
Zinc
22 studies
Filling everyday nutrient gaps
Studied 8 mg to 30 mg a day
Extensively studied
Selenium
15 studies
Filling everyday nutrient gaps
Studied 55 mcg to 200 mcg a day
Extensively studied
Copper
Filling everyday nutrient gaps
Studied 900 mcg to 2 mg a day
Well studied
Manganese
Filling everyday nutrient gaps
Studied 1.8 mg to 5 mg a day
Well studied
Chromium
13 studies
Filling everyday nutrient gaps
Studied 25 mcg to 500 mcg a day
Well studied
Molybdenum
Filling everyday nutrient gaps
Studied 45 mcg to 200 mcg a day
Well studied
Energy & Metabolism Blend
A 150 mg blend of five ingredients, listed by weight.
Supporting role
Caffeine Anhydrous
Morning alertness. In the 150 mg Energy & Metabolism Blend with four others, listed first.
Extensively studied
Green Tea Extract
17 studies
Skin health. In the 150 mg Energy & Metabolism Blend with four others, listed second.
Well studied
Eleuthero Root Powder
Energy without a stimulant. In the 150 mg Energy & Metabolism Blend with four others, listed third.
Well studied
Capsicum Seed Extract
Temperature regulation. In the 150 mg Energy & Metabolism Blend with four others, listed fourth.
Supporting role
Black Pepper Fruit Extract
Filling everyday nutrient gaps. In the 150 mg Energy & Metabolism Blend with four others, listed fifth.
Well studied
Alpha-Lipoic Acid
16 studies
Skin health
Well studied
Lutein
15 studies
Skin health
Extensively studied
Lycopene
10 studies
Skin health
Well studied
Turmeric Root Extract
Part of this formula
Supporting role
Zeaxanthin
17 studies
Eyes under bright screen light
Well studied
Astaxanthin
20 studies
Skin health
Well studied
Beta-Cryptoxanthin
Filling everyday nutrient gaps
Supporting role
Choline
10 studies
Choline status
Extensively studied
Inositol
19 studies
Clearer skin through cycle changes
Extensively studied
Silica
Hair health
Supporting role
Boron
Magnesium status
Well studied
Vanadium
Filling everyday nutrient gaps
Supporting role
In context

The gap this formula speaks to.

Public health figures the engine matched to this formula's ingredients. Reported by their source, cited and dated, never written by the brand.

52 more
Manganese

Randomised trial, 1994

Over two years, older postmenopausal women taking calcium plus trace minerals including manganese gained about 1.5% spinal bone density, while the placebo group lost about 3.5%.

Journal of Nutrition
Biotin

Meta-analysis, 2025

In a network meta-analysis of 19 trials with 1,658 participants, biotin-containing preparations were among the supplements linked to greater hair density, though most individual trials were small.

Frontiers in nutrition
Vitamin D3

Meta-analysis, 2024

Across 10 trials in 318 athletes, vitamin D3 raised blood vitamin D by about 14.8 nmol/L and hinted at better muscle strength, though few trials leave that uncertain.

Frontiers in Nutrition
Vitamin C

Meta-analysis, 2011

Across 13 trials, about 500 mg of vitamin C daily lowered blood uric acid by roughly 0.35 mg/dL.

The paper
Capsicum Seed Extract

Meta-analysis, 2020

Across 11 trials in 609 people, Capsicum annuum supplementation lowered LDL cholesterol and moved body weight only slightly.

Scientific reports
Caffeine Anhydrous

Meta-analysis, 2022

Across 21 trials at 3 to 9 mg per kg, caffeine lengthened time to exhaustion in running and shortened race completion time compared with placebo.

Nutrients
Pantothenic Acid

Randomised trial, 2014

Pantethine, a vitamin B5 derivative, lowered LDL cholesterol by about 11 percent from baseline versus placebo over 16 weeks in adults at low to moderate cardiovascular risk.

Vascular Health and Risk Management
Niacin

Systematic review and meta-analysis, 2016

Across 14 placebo-controlled trials totaling about 9,000 people, extended-release niacin lowered blood lipoprotein(a) by about 23 percent.

Metabolism
Vitamin E

Randomised trial, 2023

In 160 postmenopausal women with long-standing sleep difficulty, one month of vitamin E brought the median sleep questionnaire score to 6, versus 9 on placebo, where lower means better sleep.

Nutrients
Pantothenic Acid

Randomised trial, 2015

Pantethine lowered blood triglycerides by about 17 percent from baseline over 8 weeks in adults with moderate dyslipidemia, while a related compound, coenzyme A, lowered them further.

Journal of Clinical Lipidology
Selenium

Meta-analysis, 2019

Across 13 trials, selenium increased activity of an antioxidant enzyme and overall antioxidant capacity, and lowered a marker of fat oxidation in the blood.

Hormones
Beta-Cryptoxanthin

Meta-analysis, 2025

Pooling adult trials, carotenoid supplementation as a class was associated with small reductions in circulating liver enzyme levels, with the certainty of evidence graded low to moderate.

BMC complementary medicine and therapies
Selenium

Meta-analysis, 2018

Pooling trials, selenium raised the share of motile sperm by about 3.3 percentage points, with a smaller rise in normally shaped sperm and a higher sperm concentration.

Advances in Nutrition
Green Tea Extract

Meta-analysis, 2014

Across 13 trials, green tea catechins lowered systolic blood pressure by about 2.08 mmHg and diastolic by about 1.71 mmHg compared with control.

European Journal of Nutrition
Riboflavin (Vitamin B2)

Meta-analysis, 2024

In a dose-response meta-analysis of randomised trials, riboflavin was associated with about 1.3 fewer severe recurring headache attacks per month compared with control.

Neurological Sciences
Black Pepper Fruit Extract

Systematic review and meta-analysis, 2023

Across pooled trials in adults with a cluster of raised metabolic markers, curcumin taken with piperine lowered total and LDL cholesterol, with no significant change in triglycerides.

Phytotherapy Research
Thiamin (Vitamin B1)

Randomised trial, 2019

Thiamin supplementation did not improve left ventricular ejection fraction in the participants studied. This is a failure to detect a difference in an imaging marker, not evidence that no difference exists.

The American Journal of Clinical Nutrition
Vitamin A

Meta-analysis, 2022

Across 19 trials of about 1.2 million children in vitamin A deficient settings, supplementation lowered all-cause mortality by 12 percent (risk ratio 0.88), rated high-certainty evidence.

Cochrane Database of Systematic Reviews
Molybdenum

Metabolic balance study (crossover), 2006

In 43 healthy young women eating normal diets, over 90 percent of dietary molybdenum was absorbed and mostly excreted in urine, staying balanced across intakes of about 150 to 318 micrograms a day.

Journal of Trace Elements in Medicine and Biology
Iodine

Systematic review and meta-analysis, 2020

In pregnant women with mild to moderate iodine deficiency, iodine lowered a thyroid marker and curbed the usual pregnancy rise in thyroid size. Infant cognitive, language and motor scores showed no change across trials.

American Journal of Clinical Nutrition
Folic Acid

Meta-analysis, 2026

Pooled data found that women who had been pregnant before were more likely to take folic acid, an association about behavior, not an effect of the vitamin itself.

BMJ open
Thiamin (Vitamin B1)

Randomised trial, 2026

Thiamin supplementation improved the thiamin pyrophosphate effect, a blood marker of thiamin adequacy, in children whose levels were low.

Scientific reports
Copper

Systematic review and meta-analysis of observational studies, 2025

Pooling observational studies, higher dietary copper intake was associated with slightly higher lumbar spine bone mineral density (mean difference 0.02 g/cm2), while the hip difference was not statistically significant.

Calcified Tissue International
Riboflavin (Vitamin B2)

Meta-analysis, 2021

Pooling nine controlled trials in 673 people, vitamin B2 at 400 mg per day for three months lowered the frequency, days, duration and pain score of severe recurring headache attacks.

Nutritional Neuroscience
Vanadium

Randomised trial, 2023

In 44 adults with excess weight and high blood sugar, 12 weeks of vanadium-enriched yeast at 0.9 mg a day lowered body measurements and blood sugar markers and raised insulin sensitivity versus placebo.

Biological Trace Element Research
Zeaxanthin

Systematic review and meta-analysis, 2021

Combining 46 studies in 3,189 adults with healthy eyes, higher lutein and zeaxanthin intake raised a marker of eye pigment density more than lower intake did.

Advances in Nutrition
Silica

Randomised trial, 2005

In 50 women with sun-exposed skin, 10 mg a day of silicon for 20 weeks cut roughness by 8 to 19 percent, while placebo roughness rose and brittleness scores fell.

Archives of Dermatological Research

Population figures from public health data. Context for the category, not a statement about any individual and not a claim about this product.

What this formula earned

Every one of these is a fact the engine could ground.

Each line below was derived from this formula's own record at the time of verification. Nothing here was written by the brand, and nothing can be added that the evidence does not carry.

  • Studied in people22 human studies on Zinc back this formula, each one cited.
  • A mechanism that is settledHow Vitamin A and Vitamin C work is settled pharmacology.
  • Studied together, not just separatelyVitamin A and Vitamin E have been studied together, not only separately.
  • Recent work on the recordThe most recent study on this record was published in 2026.
  • Serving amount inside the studied rangeEach serving carries 300 mg of Vitamin C, inside the range the published research used.
  • A stated daily maintenance amountVitamin C is here at a daily maintenance amount, which is what a daily supplement is for.
  • Why this formatIt is a tablet, so the amount per serving is fixed and it stores well.
  • An absorption partner in the same servingSelenium is in the same serving as Black Pepper Fruit Extract, where it has a measured absorption role.
  • A declared blend totalEnergy & Metabolism Blend declares its total, 150 mg per serving, with 5 ingredients listed by weight.
  • Where it comes from and how it is madeVitamin A is made by more than one route.
  • Positions this formula already qualifies forThis formula already qualifies for positions beyond the one it is sold into, on the evidence it carries.
  • A position nobody is holding yetSome of those positions are ones almost nobody is selling to yet.
  • Interaction screen on the recordEvery active on this label was screened against the interaction record, and the screen is published with it.
Studied together

The combinations the trials actually measured.

Five pairings in this formula have been studied as combinations in human trials. Each finding below is what a named study measured, cited and dated, never written by the brand.

  • Lutein + ZeaxanthinVision

    In the AREDS2 trial long-term follow-up, lutein and zeaxanthin taken together were associated with a modestly lower risk of progression to late age-related macular degeneration, while the trial original primary analysis was not significant.

    Promising
  • Zinc + SeleniumImmune

    In a two-year trial in older adults, zinc taken together with selenium improved the antibody response to influenza vaccination.

    Early
  • Calcium + MagnesiumStrength

    In a 12-month randomised, double-blind trial, 98 adults aged 50 and over drank a litre a day of either a naturally calcium- and magnesium-rich mineral water or a low-mineral water. The mineral-rich group had fewer falls at the 6-month assessment and higher appendicular muscle mass, with the minerals delivered as drinking water rather than a capsule.

    Promising
  • Folic Acid + Vitamin B12 + Vitamin B6Heart

    In a 2025 network meta-analysis of 16 randomized trials in healthy adults, folic acid taken together with vitamins B6 and B12 lowered blood homocysteine more than any single supplement, with the 1 mg folic acid plus 7.2 mg B6 plus 20 micrograms B12 arm ranked most effective versus placebo (mean difference -1.03 micromol/L, 95% CI -1.71 to -0.36).

    Promising
  • Magnesium + Vitamin B6Calm

    In an 8-week randomized trial of 264 stressed healthy adults with low magnesium, magnesium plus vitamin B6 and magnesium alone reduced perceived stress about equally overall. In the prespecified subgroup that started with severe stress, the combination improved stress scores 24% more than magnesium alone.

    Early

Research strength. Research strength says how much work stands behind the combination. It is never a product score.

Fail closed. Where actives were studied on their own rather than together, each shows on its own evidence, never a combined effect no trial measured.

Independent record. Every finding is cited to a named trial, dated, and never written by the brand.

Findings from trials that studied these actives as a combination. Context for how the actives were tested together, not a statement about any individual and not a claim about this product.

How much it moves the numbers

The size of the effect, in plain numbers.

Where a trial measured an actual number, we show it next to the claim. It is the average across the trials, never a promise about one person.

Vitamin Crisk of developing a cold
Average change in the trials

About 52 percent lower risk of developing a cold, in trials of people undergoing brief periods of severe physical exertion.

Measured in
marathon runners, skiers and soldiers on subarctic exercises
Confidence interval
risk ratio 0.48, 95% CI 0.35 to 0.64

Read at the source. The magnitude sits beside the same trial the claim already cites. It describes what the trials measured, never what any one person will feel.

What the trials show

What the trials show about timing.

Time-to-effect windows the engine read from the trial record. Each is a window a named study measured, cited and dated, never written by the brand.

  • Vitamin Cwithin 24 hours of a single doseMeasured within a day

    In a randomised crossover trial, 12 healthy adults consumed 101.7 mg of vitamin C as a powder, as raw fruits and vegetables, or as juice, and plasma vitamin C rose after every intake form, with plasma and urinary levels tracked over the 24 hours following the single dose.

    Strong
  • Vitamin D3about 3 months of daily useBuilds with daily use

    In the trial record, blood vitamin D rises for about 3 months of daily vitamin D3 and then holds at a plateau, near 69 nmol/L at 1,000 IU a day, from a starting level near 41 nmol/L.

    Early
  • Vitamin Eabsorbed slowly, tracked over 72 hoursMeasured within a day

    In a 3-phase crossover using two deuterium-labelled forms of alpha-tocopherol, healthy women absorbed about 55 percent of an oral dose taken with a 40 percent fat meal and about 64 percent with a fat-free meal, with samples tracked over 72 hours. The authors conclude absorption is not limited by absent fat or fasting, and that vitamin E leaves the intestine by a prolonged process.

    Promising
  • Vitamin Kabout four weeks of daily useBuilds with daily use

    A double-blind randomised dose-finding trial gave 60 postmenopausal women aged 50 to 69 either 0, 50, 100 or 200 micrograms of menaquinone-7 daily for four weeks on a controlled diet. The ratio of carboxylated to undercarboxylated osteocalcin rose dose dependently, with significant differences from the 0 microgram group at 100 and 200 micrograms. A companion 12-week trial in 120 people aged 20 to 69 confirmed the change at 100 micrograms daily. Both studies were run by authors affiliated with the R and D division of J-Oil Mills. An independent 8-week double-blind trial in 55 healthy prepubertal children found the same direction at 45 micrograms daily. What was measured is a blood marker of vitamin K status, not bone density and not a sensation.

    Promising
  • Vitamin Kthree years of daily use, with measurements at one, two and three yearsBuilds with daily use

    A double-blind randomised trial gave 244 healthy postmenopausal women either placebo or 180 micrograms of menaquinone-7 daily for three years, with bone mineral density measured by DXA at baseline and after each year. Menaquinone-7 decreased the age-related decline in bone mineral content and bone mineral density at the lumbar spine and femoral neck, but not at the total hip. The effect is a slowed decline rather than a gain, and the trial ran three years rather than weeks.

    Promising
  • Thiamin (Vitamin B1)about 18 to 30 days of restricted intakeBuilds with daily use

    In the controlled depletion study the EFSA reference opinion reviews, restricting thiamin intake to 0.009 to 0.015 mg/MJ for 30 days brought urinary free thiamin excretion from a mean of 0.283 mg/24 h down to undetectable levels by day 18 of the depletion period.

    Promising
17 more
  • Thiamin (Vitamin B1)about 1 week of renewed intakeBuilds with daily use

    In the same depletion and repletion record the EFSA reference opinion reviews, erythrocyte transketolase activity fell progressively to about 75% of baseline during the 30-day depletion period and returned to its baseline value after 1 week of thiamin repletion.

    Promising
  • Riboflavin (Vitamin B2)about 8 weeks of daily intakeBuilds with daily use

    In an intervention the EFSA reference opinion reviews, adults whose baseline riboflavin intake and status were unknown received 5 mg/day of riboflavin for 8 weeks, and haemoglobin concentration, haematocrit and erythrocyte count all rose significantly over that period.

    Early
  • Vitamin B6about 20 to 40 days to clear after stoppingBuilds with daily use

    An expert consensus on vitamin B6 use, developed by a six-member Delphi panel with a structured evidence-quality assessment, calculated from pharmacokinetic parameters that complete clearance of vitamin B6 from the body takes a washout period of about 20 to 40 days after intake stops.

    Early
  • Folic Acida median of about 36 weeks of daily intakeBuilds with daily use

    A systematic review and Bayesian meta-analysis drew on 108 articles from 14,002 screened records and modelled blood folate against folic acid intake using one-compartment pharmacokinetic models. Red blood cell folate rose 1.78 fold from baseline to steady state at 375 to 570 ug folic acid per day, and reaching that steady state took a median of 36 weeks, 95% credible interval 27 to 52 weeks. Serum or plasma folate rose 11.6% for every 100 ug per day of folic acid intake, 95% credible interval 8.4 to 14.9.

    Strong
  • Folic Acidabout 18 days for serum folate to reach its maximumBuilds with daily use

    A kinetic study in six healthy men aged 22 to 31 gave 3.6 umol per day, 1.6 mg, of deuterium-labelled folic acid for four weeks, with folate tracked in serum, erythrocytes and urine by microbiological assay and gas chromatography mass spectrometry. Serum folate reached its maximum concentration in about 18 days, while isotopic labelling of erythrocyte folate kept rising across the whole four weeks. After supplementation stopped, red blood cell folate and urinary folate excretion declined linearly, and serum folate fell with a slow-phase half-life of 18.7 days. One study, six men, no control group.

    Early
  • Vitamin B12about 16 weeks of daily oral useBuilds with daily use

    A randomised, double-blind, parallel-group dose-finding trial in 120 older people with mild vitamin B12 deficiency, defined as serum B12 of 100 to 300 pmol/L with methylmalonic acid at or above 0.26 umol/L, gave daily oral cyanocobalamin at 2.5, 100, 250, 500 or 1000 ug for 16 weeks. Mean plasma methylmalonic acid fell 16%, 16%, 23%, 33% and 33% across those doses. Daily doses of 647 to 1032 ug accounted for 80% to 90% of the estimated maximum reduction. The window was measured on a blood marker of B12 status, not on a symptom.

    Promising
  • Vitamin B12serum levels peak about seven hours after a single tabletMeasured within a day

    An open-label randomised single-dose pharmacokinetic study in 20 healthy men aged 20 to 45, conducted and authored by staff of Emisphere Technologies, the developer of the SNAC carrier under test, measured serum vitamin B12 after one 5 mg cyanocobalamin tablet, with six men on the marketed tablet. Time to peak serum B12 was 6.83 hours for the marketed tablet and 0.5 hours for the carrier coformulation. Absolute bioavailability was 2.16% and 5.09% respectively. One trial, six men per arm. Serum concentration was measured, not any symptom.

    Early
  • Biotinabout 5 to 6 months of daily useBuilds with daily use

    In an open trial with no placebo arm, 71 patients with brittle or splitting fingernails took 2.5 mg of biotin a day. Of the 45 cases that could be evaluated, 41 were rated as having firmer and harder nails after an average of 5.5 months of treatment, standard deviation 2.3 months. The rating was clinical judgement rather than an instrument reading, and there was no control group, so the window describes when the raters recorded change, not a placebo adjusted effect.

    Early
  • Calciumwithin about one to six hours of a single doseMeasured within a day

    A randomised cross-over trial in ten women of mean age 69 gave a single 500 mg dose of calcium as citrate fasting, citrate with a meal, fortified juice or a dairy product meal, with blood drawn before and at 1, 2, 4 and 6 hours. Serum ionised and total calcium increased significantly from baseline over six hours, with the rise similar after fortified juice, delayed when citrate was taken with a meal and smaller after the dairy meal. A separate double-blind cross-over trial in 25 postmenopausal women measured parathyroid hormone and a bone resorption marker 12 hours after a single calcium dose. Ten participants is a small sample, and what moved was blood chemistry, not a sensation.

    Promising
  • Iodinefrom about eight weeks, deepening through twenty-four weeksBuilds with daily use

    In a 24 week randomised double-blind placebo-controlled trial in 112 mildly iodine-deficient New Zealand adults aged 18 to 40, 150 micrograms of iodine a day as potassium iodate lowered thyroglobulin, a blood marker of iodine status, by 12 percent at 8 weeks, 20 percent at 16 weeks and 27 percent at 24 weeks compared with placebo. Median urinary iodine reached 168 micrograms per litre against 79 on placebo. TSH and free T4 stayed within normal range and did not change significantly.

    Promising
  • Zincover about five days of lozenges started within 24 hours of symptom onsetBuilds with daily use

    Across three randomised placebo-controlled trials pooled as individual patient data (199 adults with naturally acquired colds, 80 to 92 mg of elemental zinc a day as acetate lozenges), 70 percent of the zinc group had recovered by day 5 against 27 percent on placebo, and colds ran 2.73 days shorter against a 7 day average duration. A separate meta-analysis of seven lozenge trials (575 participants, doses above 75 mg a day, zinc acetate or zinc gluconate) measured cold duration 33 percent shorter, with no significant difference between the two salts.

    Strong
  • Zincabout two to four weeks of daily intakeBuilds with daily use

    In a controlled feeding study in nine healthy men, six weeks of restricted zinc intake raised DNA strand breaks in peripheral blood cells, and four weeks of repletion at 11 mg a day, with 20 mg of supplemental zinc for the first seven days, reversed the rise. In a separate randomised placebo-controlled trial in 40 Ethiopian women eating a high-phytate diet, 20 mg a day of zinc sulfate for 17 days lowered mean comet tail moment from 39.7 to 30.0 while plasma zinc did not change significantly. Both windows were measured on a DNA damage marker in blood cells, not on a symptom.

    Early
  • Seleniumabout ten weeks of daily useBuilds with daily use

    In a 12 week randomised double-blind placebo-controlled trial in 119 healthy UK adults aged 50 to 64, mean plasma selenium rose from 95.7 ng/mL at baseline to steady state by week 10, reaching 118.3, 152.0 and 177.4 ng/mL on 50, 100 and 200 micrograms a day of selenium-enriched yeast. Plasma selenoprotein P rose in every selenium arm. Platelet glutathione peroxidase activity did not change significantly at any dose or form.

    Promising
  • Copperabout four to eight weeks of daily useBuilds with daily use

    In an 8 week pilot with a parallel placebo group, 8 young women taking 2 mg of copper a day as copper glycinate showed a 9 percent mean rise in serum ceruloplasmin and a 75 percent rise in diamine oxidase, alongside a 39 percent fall in plasma F2-alpha isoprostanes. Erythrocyte copper-zinc superoxide dismutase did not change. In a separate 4 week double-blind crossover in 20 men with moderately high cholesterol at the same 2 mg a day, copper moved no measure across the whole group and raised superoxide dismutase and diamine oxidase only in the 10 men who started below the median. Both are small and both measured enzymes in blood, not a symptom.

    Early
  • Caffeine Anhydrouswithin about 45 to 60 minutes of a single doseMeasured within a day

    In a double-blind placebo-controlled crossover trial, 15 resistance-trained women took 4 mg per kg body mass of caffeine 60 minutes before a strength and power battery. Squat one-repetition maximum rose 4.5 percent and countermovement jump height 7.6 percent against placebo. A separate crossover trial in 11 active adults began its cycling tests 45 minutes after a 3 mg per kg capsule and recorded a peak-power increase of about 4 percent on the first day of ingestion.

    Norum et al., 2020PMID 32681596
    Lara et al., 2019PMID 30673725
    Promising
  • Caffeine Anhydrousheld for about 15 to 18 days of daily use, then narrowedBuilds with daily use

    One crossover trial mapped the day-to-day time course in 11 healthy active adults taking 3 mg per kg per day for 20 consecutive days. Peak cycling power in the incremental test stayed about 4.0 percent above placebo for the first 15 days and the difference then lessened. Wingate peak power was still raised on days 1, 4, 15 and 18 by about 4.9 percent. The authors describe the shrinking margin as progressive tolerance. This is one trial with 11 participants.

    Lara et al., 2019PMID 30673725
    Early
  • Green Tea Extractabout 12 weeks of daily useBuilds with daily use

    In a 12-week randomised, double-blind, placebo-controlled trial, 80 middle-aged adults with self-reported memory complaints took heat-treated green tea extract or placebo. The extract group showed a greater improvement in a standardised composite memory score at week 12, alongside increased functional connectivity within the default mode network on imaging. One trial of 80 people, in a population with subjective complaints rather than measured impairment.

    Promising

Windows measured in the cited trials. Context for how the active behaves over time, not a statement about any individual and not a claim about this product.

General timing

How each ingredient usually behaves over time.

12 ingredients, from each one's own page.

  • Vitamin AWeeks, not days

    Weeks to months. Liver stores buffer intake, so vitamin A status moves slowly and shows up on a blood panel rather than as a sensation.

    Its own page, the plain answer on timing

  • Vitamin CWithin hours

    Blood levels rise within hours and tissue pools fill over days. Collagen-linked changes in skin and gums build over weeks and show as tissue quality, not as a sensation.

    Its own page, the plain answer on timing

  • Vitamin D3About six to twelve weeks

    25-hydroxyvitamin D climbs over roughly six to twelve weeks of daily dosing before it plateaus. It's a blood level you watch rather than a feeling.

    Its own page, the plain answer on timing

  • Vitamin EWeeks, not days

    Plasma alpha-tocopherol climbs within days of daily intake, and anything you'd notice in skin condition is a slow change across a couple of months.

    Its own page, the plain answer on timing

  • Vitamin KWithin days

    Clotting factor carboxylation responds within days. The bone marker undercarboxylated osteocalcin shifts across roughly four to twelve weeks, so this shows up on a panel.

    Its own page, the plain answer on timing

  • Thiamin (Vitamin B1)

    There is no onset to time in the usual sense. Status markers such as erythrocyte transketolase activity move across weeks, and that is where the change is read.

    Its own page, the plain answer on timing

6 more
  • Riboflavin (Vitamin B2)Within hours

    Urine turns bright yellow within hours of the first dose. Status itself, read as red cell glutathione reductase activity, shifts across two to eight weeks.

    Its own page, the plain answer on timing

  • Niacin

    Nothing to wait for at everyday amounts. Niacin status shows up on blood work rather than as a sensation. The flush from the nicotinic acid form arrives within 30 minutes.

    Its own page, the plain answer on timing

  • Vitamin B6

    Nothing quick. Conversion to the active coenzyme happens within hours, but plasma pyridoxal 5-phosphate takes a couple of weeks to settle at a new level.

    Its own page, the plain answer on timing

  • Folic AcidWithin a few hours

    Serum folate climbs within a few hours of a dose and red cell folate takes about eight to twelve weeks to plateau. The change lands on a blood panel, not in how you feel.

    Its own page, the plain answer on timing

  • Vitamin B12

    Markers move first. Methylmalonic acid and homocysteine start shifting within a week or two, while anything you would notice takes several weeks of daily use.

    Its own page, the plain answer on timing

  • BiotinAbout 8 to 12 weeks

    Fingernails grow around 3mm a month, so it takes roughly 8 to 12 weeks before enough new plate has grown out to judge the difference by eye.

    Its own page, the plain answer on timing

How each ingredient usually behaves over time, from its own page on IngredientMD. General timing for the ingredient, not a measurement of this product.

Chemical form

The same ingredient, carried differently.

What each form is, and where it fits in a formula. Measured findings carry the study that reported them.

  • Cholecalciferol (vitamin D3)

    The animal-sourced form of vitamin D, made in skin under UVB light and produced commercially from lanolin. Fat-soluble, so it travels with dietary fat and is stored in body fat.

    Fits
    Raising and holding vitamin D status, and the form most supplement trials use.
    Trade-off
    Being fat-soluble it accumulates with sustained high dosing, so intakes are set against the tolerable upper level rather than topped up freely.

    In a 12-week double-blind randomised controlled trial in 108 young women in urban Bangalore, most of whom began vitamin D-deficient, daily vitamin D3 at 400, 600 or 800 IU in a fortified wafer raised serum 25-hydroxyvitamin D, parathyroid hormone fell over time, and effects on bone-turnover markers were modest and not dose specific. The 800 IU dose brought 65 percent of participants to sufficiency.

  • Riboflavin

    The free vitamin B2 molecule, an isoalloxazine ring joined to a ribitol sugar chain, supplied as the unmodified crystalline compound with no added salt or phosphate group.

    Fits
    It is the form most panels list simply as riboflavin or vitamin B2.
    Trade-off
    It is intensely yellow and only sparingly water soluble, so it can tint a finished product and tends to resist dissolving cleanly in a liquid or a fast-melt format.
  • Nicotinic acid

    The free-acid form of vitamin B3, pyridine-3-carboxylic acid. It is the reference form of niacin, a small water-soluble molecule carrying a bare carboxylic acid group on the pyridine ring.

    Fits
    The long-standing reference form for meeting a vitamin B3 requirement.
    Trade-off
    This is the form behind the familiar warm, tingling skin flush that many people notice soon after a larger dose, a recognized property of the free acid that leads some formulators to reach for an amide or ester instead.
  • D-pantothenic acid

    The free acid form of vitamin B5, an amide of pantoic acid and beta-alanine, supplied as a viscous hygroscopic oil or a stabilised liquid rather than a dry salt.

    Fits
    The un-neutralised acid carries no mineral counterion, so it suits liquid drops, syrups and formats where a calcium or sodium salt is not wanted.
    Trade-off
    It is hygroscopic and tends to draw water and turn sticky, which makes it awkward to hold as a dry powder without added stabilisers.
  • Caffeine anhydrous

    Dry crystalline free base with no water of crystallisation, close to a hundred percent caffeine by weight

    Fits
    Capsules, tablets and pre-workout powders where an exact milligram figure is needed
    Trade-off
    Potency by volume makes it unforgiving to measure by spoon and it dissolves slowly in cold water. The same potency is what makes accurate dosing possible on a scale
  • Alpha-lipoic acid (racemic)

    A 50:50 mixture of the R and S enantiomers of lipoic acid, sold as the free acid. The same molecule is also labelled thioctic acid.

    Fits
    A low-cost form to produce and the one used across most of the older clinical literature, which makes it a straightforward default for a general-purpose formula.
    Trade-off
    Half of the labelled material is the S enantiomer, which does not occur naturally, and as a free acid it can polymerise when exposed to heat or stomach acid.

    In an open-label four-way crossover in 24 adults, a racemic solution produced higher peak plasma concentrations of both enantiomers than the 200, 300, and 600 mg tablet forms.

  • 1 more
  • Myo-inositol

    The most common naturally occurring stereoisomer of inositol, a six-carbon sugar alcohol (cyclohexanehexol). It is the form found in most foods and in the body's own inositol pool, and is supplied as a free white crystalline powder.

    Fits
    It dissolves readily in water with a mild sweet taste, so it suits high-gram powders, stick packs and drink mixes where a large scoop needs to go into solution cleanly. It is also the form the bulk of inositol research has used.
    Trade-off
    Doses are counted in grams rather than milligrams, so it adds noticeable bulk to a capsule line and usually pushes a product toward a powder or several capsules per serving.

Descriptions of the form itself, read from the cited studies. Not a comparison between products and not a statement about any individual.

Format

Tablet

It is a tablet, so the amount per serving is fixed and it stores well.

Best forHigh-dose minerals and anything needing timed or delayed release.
From the same shelf

Studied alongside this brand's other formulas

Where two of this brand's products carry actives the literature has read together, the pairing and its basis are below. The evidence word is the corpus row's own confidence, never a score.

Pro Performance Whey Protein 24g + Mega Men MultivitaminEstablished

Riboflavin supplies the FAD carried by the E3 subunit of the branched-chain ketoacid dehydrogenase complex and by the acyl-CoA dehydrogenases downstream. It sits inside the same enzyme machinery.

FAD cofactor of the dehydrogenase complex. No combination trial has tested this exact pairing.

Pro Performance Whey Protein 24g + Mega Men MultivitaminEstablished

NAD+ takes the electrons from the branched-chain ketoacid dehydrogenase reaction, and niacin is its precursor. The complex requires thiamine, lipoate, FAD and NAD together.

NAD acceptor for the dehydrogenase step. No combination trial has tested this exact pairing.

Pro Performance Whey Protein 24g + Mega Men MultivitaminEstablished

3-methylcrotonyl-CoA carboxylase in leucine breakdown is biotin-dependent. Leucine metabolism runs through a biotin enzyme regardless of ratio.

cofactor for a carboxylase in the leucine route. No combination trial has tested this exact pairing.

Questions shoppers ask

Is Mega Men Multivitamin independently verified?
Yes. IngredientMD reviewed this formula independently and verified it in Oct 2026. The verdict is earned, not bought: brands can't edit or purchase it.
What's in Mega Men Multivitamin?
Mega Men Multivitamin is built on Vitamin A, Vitamin C, Vitamin D3, Vitamin E, Vitamin K, Thiamin (Vitamin B1), and more. Each ingredient links to its own evidence page on IngredientMD.
Were ingredient interactions checked?
Yes. The combination was screened against 8,335 documented interactions for these actives in IngredientMD's interaction database.
Who is IngredientMD?
IngredientMD is an independent supplement-science platform. We analyze ingredients and formulas against clinical research, and we verify products only when they clear our bar. Labs run the tests. We review the results.
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This record is not medical advice. Always consult your healthcare provider before starting any supplement regimen.

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