* Kaufman et al., JAAD (1998). Propecia prescribing information, Clinical Studies: men ages 18 to 41 with vertex hair loss; two initial trials enrolled 1,553 men and 1,215 continued into the second year. Photographic endpoint, not a 66% increase in hair count. Results require continued treatment and vary. The studied dose is not a dosing instruction. Comparison for the 66% result: Men taking finasteride 1 mg daily showed more hair growth in photos after two years. Placebo: 7%. For 83%: Original source. Propecia prescribing information, Clinical Studies, Studies in Men, hair-count results. Derived as 100% minus 17% with any hair-count decrease from baseline at two years on oral finasteride 1 mg/day; placebo 72% had a decrease. Counts were taken in a 1-inch-diameter vertex scalp area, not the whole head. The related photographic improvement endpoint was assessed separately. Both the 66% photographic result and the 83% hair-count calculation are reported in the Propecia prescribing information, Clinical Studies, Studies in Men with Vertex Baldness. Two-year studies of oral finasteride measured both hair counts and visible improvement.