Hair Weights with Finasteride

One of the most carefully conducted studies investigating the benefits of finasteride in treating male pattern balding was in 2002. It was a 96 week study by Vera Price and colleagues. This study not only looked at changes in hair numbers before and after starting finasteride but also hair weights- the actual mass of hairs in a square centimetre area before and after treatment. These studies showed that after using finasteride, hair weights were greater than placebo (25.6% +/- 3.6% [18.5, 32.7] and 35.8% +/- 4.6% [26.7, 44.8] at 48 and 96 weeks, respectively; P <.001 for both time points). This data is important because it showed that finasteride helped men with hair loss by thickening many hairs - which we know now to represent a conversion of some of the vellus-like and miniaturized hairs to thicker terminal hairs. 

Reference

Price VH, et al. Changes in hair weight and hair count in men with androgenetic alopecia after treatment with finasteride, 1 mg, daily. Randomized controlled trial J Am Acad Dermatol. 2002.