What supplements help hair growth?
Fix deficiencies first: iron (most common cause in women), vitamin D (42% deficient), zinc. Biotin only works if deficient (rare). Marine collagen has moderate evidence. Most "hair growth" supplements are marketing. Get blood work before spending money.
- Iron deficiency: #1 fixable cause
- Vitamin D: get tested
- Biotin: only if deficient (rare)
- Get blood work before buying supplements
Fix Deficiencies First (This Is Usually the Answer)
Iron deficiency is the most common nutritional cause of hair loss in women, and fixing it restores growth in most cases within 3-6 months. Get your ferritin tested. Below 30 ng/mL is associated with hair loss even if your hemoglobin is normal.
Vitamin D deficiency is linked to hair thinning too. 42% of adults are low. Get tested. Supplement with 2,000-5,000 IU D3 if you're under 40 ng/mL.
Biotin deficiency causes hair loss, but actual deficiency is rare in people eating a normal diet. The 10,000mcg biotin supplements are massive overkill for most people. If you're not deficient, extra biotin won't grow more hair. You'll just have expensive urine.
Quick Tips
- →Get ferritin and vitamin D blood tests first
- →Iron deficiency: most common fixable cause in women
- →Biotin only helps if you're actually deficient (rare)
What Has Some Evidence
Marine collagen peptides (5-10g daily): a few trials show improvements in hair thickness and growth rate after 3-6 months. The evidence is moderate. Not a miracle worker but some women report noticeable results.
Saw palmetto (320mg daily): may help with androgenetic alopecia in men by blocking DHT (similar mechanism to finasteride but weaker). 60% reduction in hair loss in one small study. Not as strong as prescription options.
Zinc (15-30mg daily): zinc deficiency causes hair loss. If you're low, supplementing helps. If you're not low, extra zinc won't do anything for your hair. Don't exceed 40mg/day long-term.
What's Probably a Waste
Most "hair, skin, and nails" gummies are biotin (which you probably don't need) plus vitamins you're already getting from food. At $25-40/month, that's a bad deal.
Keratin supplements: your body breaks them into amino acids. They don't go directly to your hair. Just eat protein.
Folate, B12, vitamin E as standalone hair supplements: only useful if you're deficient. For most people eating a normal diet, they're unnecessary for hair specifically.
Key Takeaways
Step 1: get blood work (iron, ferritin, vitamin D, thyroid). Step 2: fix any deficiencies found. Step 3: wait 3-6 months. That alone resolves most nutritional hair loss. If blood work is normal and you're still losing hair, it's probably genetic or hormonal. See a dermatologist. A $30 supplement won't fix what a $300 medical evaluation can actually diagnose.
Ingredients Mentioned
Iron
Vitamin D3
Collagen Peptides
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