Short answer: Two drugs are FDA approved for pattern hair loss: finasteride 1 mg (Propecia), for men only, and topical minoxidil (Rogaine), for men and women. Both take months to show results, and benefit fades after stopping. Oral minoxidil is approved only for hard-to-treat high blood pressure. GHK-Cu, often sold for hair, has one small trial of a combination cream and no trials of injections.
| Compound | Best evidence | What it shows |
|---|---|---|
| Finasteride 1 mg (Propecia) | FDA-approved for this | Approved for male pattern hair loss in men only. In two 1-year trials of 1,553 men, it added 107 hairs vs placebo in a 1-inch circle of the crown at 1 year. |
| Topical minoxidil (Rogaine) | FDA-approved for this | Sold without a prescription to regrow hair on the top of the scalp. The men's label says results may take 2 to 4 months; the women's label says up to 6 months. |
| Oral minoxidil | Approved for a different use | The tablet is approved only for severe high blood pressure. In a 24-week trial in men, it did not beat topical minoxidil. |
| GHK-Cu | Small or early human studies | One 45-man trial tested a product combining GHK with another compound, 5-ALA. No human trial of injected GHK-Cu for hair has been published. |
"Animal or lab studies only" means no published human trial for this goal that we could find. Results in rats or cells often do not carry over to people. Compounds that are not FDA-approved have no tested label for dose, purity or safety.
Pattern hair loss (androgenetic alopecia) happens when hair follicles shrink over time under the effect of DHT, a hormone made from testosterone. Finasteride blocks the enzyme that makes DHT.
The 1998 finasteride trials enrolled 1,553 men aged 18 to 41. Hair counts rose by 107 hairs at 1 year and 138 at 2 years compared with placebo, in a 1-inch circle where men started with about 876 hairs. Men on placebo kept losing hair.
Minoxidil tablets are approved only for high blood pressure that has not responded to a diuretic plus two other blood pressure drugs. The label warns they can cause fluid around the heart and worsen chest pain.
Low-dose oral minoxidil is widely discussed for hair. A 2024 randomized trial in Brazil compared a daily oral tablet with twice-daily 5% topical minoxidil for 24 weeks in men; 68 of 90 finished. Oral minoxidil was not better on the main measure, hair density. Photos favored it on the crown only. Unwanted body and facial hair affected 49% of the oral group.
The only placebo-controlled hair trial with GHK we found tested a product combining GHK with 5-aminolevulinic acid (5-ALA) in 45 men for 6 months. Hair counts rose more than on placebo, but the trial was small, and it cannot separate the effect of GHK from the effect of 5-ALA.
A 2026 systematic review of GHK-Cu found decades of lab and animal work but called the human evidence thin and fragmented. It lists androgenetic alopecia among the uses that still need well-designed human trials, and notes about 35% of the research includes authors from one research group. FDA lists injectable GHK-Cu as a compounding concern because of possible immune reactions and limited human data. For GHK-Cu creams on skin, see skin and hair.
Terms on this page: Peptide · Research use only (RUO) · Compounding pharmacy