- Can a zinc deficiency directly cause hair thinning or increased shedding? Studies link low serum zinc to diffuse shedding and alopecia areata, and severe deficiency states cause hair loss that reverses when zinc is replaced. The evidence is mostly observational, the one supplementation study was small and uncontrolled, and zinc is not a treatment for pattern hair loss.
- Is Selenium more effective when taken orally or applied topically in shampoos or serums? The two are not interchangeable and the evidence points the other way from the common assumption: topical selenium disulfide shampoo has clinical trial support for dandruff and seborrheic dermatitis, while oral selenium supplements have no reliable evidence for hair growth in people who are not deficient, and excess intake is a recognised cause of hair loss.
Popular 5-alpha reductase inhibitor that lowers DHT, taken as a pill or used topically
5-alpha reductase inhibitor that blocks both enzyme types, a stronger DHT blocker than finasteride
Vitamin made in the skin from sunlight, also taken as a supplement
Oil from the neem tree, used in traditional remedies
autoimmune disorder causing patchy hair loss