BULK Pre-Workout.

59 to 66 days

was the median time it took adults to make a new daily health habit automatic across the studies a 2024 review pooled, with individuals ranging from 4 to 335 days.

61% to 74%

of adults refilling a daily long-term medicine on their own had stopped within a year, against 33% to 44% of those whose refills were scheduled to one recurring pickup day, in a matched pharmacy cohort.

57.6%

During 2017 to 2018, 57.6% of US adults aged 20 and over reported using a dietary supplement in the past 30 days.

Systematic review and meta-analysis, 2019

Pooled across 8 trials, L-citrulline lowered systolic blood pressure by about 4.1 mmHg, with a diastolic drop of about 2.8 mmHg seen only at doses of 6 grams a day or more.

Systematic review and meta-analysis, 2021

Across 8 studies, taking 6 to 8 grams of citrulline malate 40 to 60 minutes before strength training raised repetitions completed before muscular failure by about 6.4 percent.

Meta-analysis, 2025

Across 15 randomised trials in middle-aged and older adults, l-citrulline or watermelon intake lowered systolic blood pressure by about 4.0 mmHg and diastolic by about 2.5 mmHg.

A median improvement of about 2.85 percent in exercise measures

Improves the ability to keep going in efforts lasting one to four minutes. Measured in efforts lasting about one to four minutes (interquartile range -0.4 to 10.5 percent).

Systematic review and meta-analysis, 2017

Across 40 placebo-controlled studies in 1,461 people, beta-alanine produced a small but significant overall gain in exercise outcomes (effect size 0.18), with the clearest benefit for high-intensity efforts lasting roughly 0.5 to 10 minutes.

Systematic review and meta-analysis, 2020

Combining individual data across trials, about 99 percent of people taking beta-alanine raised their muscle carnosine, though modelling suggests typical doses don't fully saturate muscle stores.

Meta-analysis, 2026

Across 11 trials in 312 women, beta-alanine improved time to exhaustion, but power, anaerobic performance, oxygen uptake and body fat findings were too imprecise to call, with very low certainty.

A small to moderate gain in maximal strength (standardized effect 0.47), largest in the lower body

Builds maximal strength when taken consistently over time. Measured in healthy people aged 15 to 60, pooled across 17 trials (0.04 to 0.89).

Meta-analysis, 2025

In healthy adults, across trials, L-theanine with caffeine modestly improved accuracy on an attention-switching task, and L-theanine alone modestly sped up choice reaction time.

Systematic review, 2020

Across 9 trials, 200 to 400 mg a day of L-theanine may help lower stress and anxious feelings in people facing stressful situations.

Randomised trial, 2019

In a 4-week trial in 30 healthy adults, 200 mg a day of L-theanine improved sleep quality scores, with faster sleep onset and less disturbance.

Meta-analysis, 2024

In a review of 17 betaine trials in healthy people, at least a week of use increased maximal muscular strength, with a pooled effect size of about 0.47 and the clearest gain in the lower body.

Systematic review, 2026

The review of citrulline supplementation in postmenopausal women reports vascular measures as the most consistently affected domain, with muscular and metabolic findings less consistent across the included studies.

Meta-analysis, 2021

Pooling 10 study groups of athletes, beta-alanine did not significantly change Yo-Yo test performance overall, though protocols lasting 6 to 12 weeks showed a benefit (standardised mean difference 1.02).

Meta-analysis, 2021

Across pooled trials, betaine raised total cholesterol by a modest amount.

Meta-analysis, 2025

Pooling 8 randomised trials in 176 middle-aged and older adults, l-citrulline improved flow-mediated dilation, a measure of blood vessel widening, by about 1.8 percentage points, while pulse wave velocity showed no clear change.

Meta-analysis, 2021

Pooling human trials, betaine supplementation lowered plasma homocysteine by about 1.3 micromol/L versus control.

Meta-analysis, 2022

Pooling randomised trials, betaine supplementation did not produce a detectable change in body fat or lean mass.

Meta-analysis, 2023

A systematic review and meta-analysis of randomised controlled trials pooled the effect of betaine supplementation on circulating inflammatory markers. The endpoints are blood markers rather than clinical outcomes.

Meta-analysis, 2022

Across 20 randomised trials in 492 participants, beta-alanine showed no detectable effect on body mass (-0.15 kg), fat mass, body fat percentage or fat-free mass, at any dose or training type.

Systematic review, 2026

Across dietary supplementation trials the authors reported that sleep findings for L-theanine were mixed and often based on self-reported measures, so the effect remains uncertain.

Systematic review, 2024

The authors found the available trials few and heterogeneous, and concluded that effects of L-theanine on measured psychiatric rating-scale outcomes stayed uncertain.

Meta-analysis, 2025

Across 21 randomised trials, l-citrulline showed no overall effect on body weight, fat mass or fat-free mass, with reductions in fat mass only in exploratory subgroups over age 40 or above 6 g a day.

Meta-analysis, 2025

Pooling the randomised trials, L-theanine was linked to small improvements in self-reported sleep quality, while objective sleep measures showed no detectable difference.