No supplement has strong clinical evidence for reversing androgenetic alopecia on its own. The condition is driven by genetic sensitivity to DHT, a hormonal mechanism that over-the-counter supplements cannot adequately address. However, specific nutritional deficiencies can worsen hair shedding alongside pattern hair loss, and correcting those deficiencies is worth the effort. Here is the honest evidence on every major supplement marketed for hair loss.
This article is for informational purposes only and does not constitute medical advice.
Supplements With Some Evidence
These supplements have at least preliminary clinical data supporting a role in hair health, though none approach the effectiveness of prescription medications like finasteride (80 to 90% halt rate) or minoxidil (40 to 60% regrowth).
1. Saw Palmetto
Saw palmetto extract (Serenoa repens) is the most commonly cited natural alternative to finasteride. It inhibits 5-alpha reductase, the same enzyme that finasteride targets, but to a much lesser degree.
The evidence: A small number of studies suggest saw palmetto may improve hair count by 10 to 15% over 12 to 24 months. A 2020 review of 7 studies found a positive effect on hair growth, but the study sizes were small (under 100 participants each) and the improvements were modest compared to finasteride.
The reality: Saw palmetto reduces DHT far less effectively than finasteride's 70% reduction. It is not a replacement for prescription medication. Some men use it as an adjunct to finasteride or as a starting point before committing to prescription treatment.
Typical dose: 320mg daily of standardized extract.
2. Iron (Ferritin)
Iron deficiency is one of the most common correctable factors contributing to hair shedding. Low ferritin (stored iron) can trigger telogen effluvium, which compounds the thinning already caused by androgenetic alopecia.
The evidence: Multiple studies link ferritin levels below 40 ng/mL to increased hair shedding. Supplementing iron in deficient patients reduces shedding and can improve overall hair density.
The reality: Iron supplementation only helps if you are actually deficient. Taking iron with normal ferritin levels provides no hair benefit and can cause side effects (constipation, nausea). Get your ferritin tested before supplementing.
Typical dose: 65 to 200mg elemental iron daily if deficient, taken with vitamin C for better absorption.
3. Zinc
Zinc is involved in hair follicle function, protein synthesis, and cell division. Zinc deficiency is associated with diffuse hair loss, and several types of alopecia have been linked to low zinc levels.
The evidence: A 2013 study found that serum zinc levels were significantly lower in patients with hair loss compared to healthy controls. Supplementation in deficient patients improved hair growth in some cases.
The reality: Like iron, zinc supplementation only benefits people with a deficiency. Excessive zinc intake (over 40mg daily long term) can cause copper depletion, which itself contributes to hair loss. Test your levels first.
Typical dose: 15 to 30mg daily if mildly deficient. Higher therapeutic doses should be supervised by a doctor.
4. Vitamin D
Low vitamin D levels are increasingly associated with hair loss conditions, including androgenetic alopecia. Vitamin D receptors are present in hair follicles and play a role in the hair cycle.
The evidence: Several observational studies find that men with androgenetic alopecia have lower serum vitamin D levels than controls. However, it remains unclear whether low vitamin D is a cause, a consequence, or simply a coincidental finding.
The reality: Correcting a vitamin D deficiency (below 30 ng/mL) is good medical practice regardless of hair loss. Whether supplementation beyond sufficiency improves androgenetic alopecia specifically is not established.
Typical dose: 1,000 to 4,000 IU daily, adjusted based on blood levels.
Supplements With Weak or No Evidence
5. Biotin
Biotin (vitamin B7) is the most heavily marketed hair supplement, found in virtually every "hair growth" product. Despite this, the evidence for biotin supplementation in people without a deficiency is essentially nonexistent.
The evidence: Biotin deficiency does cause hair loss, but true deficiency is rare in people eating a normal diet. Multiple reviews conclude that biotin supplementation does not improve hair growth in individuals with adequate biotin levels.
The reality: Most biotin supplements contain 5,000 to 10,000 mcg, which is 166x to 333x the adequate daily intake (30 mcg). Excess biotin is excreted in urine and provides no additional hair benefit. One practical concern is that high-dose biotin can interfere with certain lab tests, including thyroid panels and troponin assays.
6. Collagen
Collagen supplements are marketed for hair, skin, and nails. Collagen provides amino acids (glycine, proline, hydroxyproline) that the body uses for various structural proteins.
The evidence: No controlled clinical trials demonstrate that collagen supplementation improves androgenetic alopecia. The amino acids in collagen are available from any protein source.
7. Marine Protein Supplements
Products containing marine extracts (shark cartilage, fish protein) claim to nourish hair follicles. A few small studies show modest hair count improvements, but the evidence is insufficient to draw conclusions. These products are typically expensive ($30 to $60 per month) relative to their unproven benefit.
The Bottom Line on Supplements
Supplements address nutritional deficiencies, not androgenetic alopecia itself. The hierarchy of effectiveness is clear: finasteride and minoxidil first, PRP therapy for additional support, and supplements only to correct documented deficiencies.
Before spending money on supplements, get blood work to check ferritin, zinc, vitamin D, and thyroid function. Correct any deficiencies found. Then focus your budget on proven medical treatments.
Check your Norwood scale stage and explore evidence-based treatments including surgical options if supplements and medication are not enough.
Get a free AI assessment of your hair loss at myhairline.ai/analyze.