A new meta-analysis including 23 studies, published in JAMA Dermatology, analyzed research on the impact of using different dosages of three oral and topical medications - minoxidil, dutasteride and finasteride, for a period of two to four months - on thinning male hair.

The analysis revealed that 0.5 milligrams a day of oral dutasteride was tied to the highest probability of reducing hair loss. Use of 5 milligrams a day of oral finasteride was found to be second in effectiveness. Finasteride led to the greatest increase in total hair count at 48 weeks.

5 milligrams of oral minoxidil stood third in the treatment for male-pattern baldness. Minoxidil yielded the greatest increase in terminal hair count at two months, which was much stronger than the lower dose of the drug. Finasteride 1 milligram a day was at the fourth place in the ability to reduce male hair loss, while 5% topical minoxidil was fifth in effectiveness, and 2% solution of topical minoxidil stood sixth in effectiveness. Use of 0.25 milligrams a day of oral minoxidil stood last in effectiveness against male-pattern hair loss… (CNN, February 6, 2022)