Biotin gummies / 'hair vitamins' regrow hair
Biotin deficiency is real — almost nobody has it. For deficient users, supplementation restores hair growth; for everyone else, it's a $20/month placebo with a real risk of interfering with lab tests.
What the evidence says
The studies, decoded
Patel 2017 systematic review: 18 case reports of biotin deficiency where supplementation reversed hair-and-nail symptoms. Importantly, all 18 had documented underlying deficiency (genetic, drug-induced, or malnutrition). No RCT has shown benefit in non-deficient users. The FDA has issued safety communications because high-dose biotin INTERFERES with thyroid and troponin lab assays — meaning your hair gummy can give you a false positive heart-attack screen.
How it actually works
Mechanism
Biotin is a cofactor for carboxylases involved in fatty acid synthesis and keratin production. Without enough biotin, keratinization breaks down — and hair/nails are the first visible symptom. WITH enough biotin (the standard case), more doesn't do more.
What to actually expect
Realistic outcome
Don't bother. If you genuinely suspect deficiency (rare diet, anti-epileptic drugs, GI surgery), test and treat. Otherwise: save the $20/month and warn your doctor before lab work if you took some.
If this is overhyped — what is not
Better alternatives
Fix protein intake (1.2-1.5g/kg/day). Iron (especially women) and vitamin D if low. For hair growth specifically: see minoxidil and finasteride.
Sources
Citations
- A review of the use of biotin for hair lossPatel et al., 2017, Skin Appendage Disord
Minoxidil 5% topical regrows hair
About 60% partial regrowth, 80% slowed progression at 12 months. OTC, well-tolerated. Lifetime commitment — stop and the gain reverts.
WorksFinasteride (Propecia) stops and partially reverses hair loss
The most-studied AGA drug. Reduces DHT by ~70%. Stable or improved density in 80-90% of users over years. Sexual side effects 1-4%, mostly reversible.
OverhypedCollagen powder improves skin, hair and joints
Some signal for skin elasticity and joint pain at 10g+/day. But your body breaks collagen into amino acids — protein-adequate diets get 90% of the same benefit cheaper.
WorksVitamin D supplementation improves health and looks
Real benefit IF you are deficient. Most populations are. Aim for serum 25-OH-D 40-60 ng/mL. Test, don't guess. No incremental benefit past sufficient.