Description

Finasteride began its life as a targeted therapy for benign prostatic hyperplasia, yet it has become best known for preserving a youthful hairline – a reputation that’s made it a staple for actors, models, and anyone chasing aesthetic confidence. Today, online pharmacies dispense finasteride after little more than a brief questionnaire, fuelling a booming U.S. market valued at over $120 million in 2024 and still growing. But this anti-androgen treatment carries real risks: while the FDA cites a 2 percent increase in sexual dysfunction, other studies suggest it may be significantly higher. Many discontinue the drug when side effects appear, and although most resolve, a small but significant fraction find their symptoms persist indefinitely, often devastating their quality of life. Nearly 1,400 lawsuits against Merck have resulted in $4.3 million in payouts, underscoring the severity of these effects. How can a medication continue to leave impairment long after it’s left the body? In this book, I unpack the surprising science behind finasteride’s lasting effects, tracing its impacts through hormones, genes, and even the gut.