Musculoskeletal adverse events of finasteride

When men take finasteride for hair loss, their attention is directed to the hair and scalp. When adverse events (AEs) occur in other systems and areas of the body, it might not be obvious that finasteride could be the culprit. But Merck’s research established that the drug serves to lower dihydrotestosterone in the blood as … Read more

Disability and deaths in men who used finasteride

Databases of drug adverse events contain tremendous variation. They include reports from patients of all ages, and many took other drugs that might explain outcomes. In this analysis, cases were limited to men ages 18–40 where the ‘Suspected Product’ field only contained finasteride or minoxidil. This is only a fraction of total cases, but helps … Read more

From the deep: why finasteride harms took decades to emerge

Researchers blamed growing safety concerns on patients, overlooking social context and weaknesses in safety regime The official view of Propecia, fashioned by Merck at a reported cost of $450 million, is that the drug is safe and effective. Upon approval by FDA in 1997, this view was carried forward by dermatologists, some of whom were … Read more

FDA quashed internal warning on suicidality linked to Propecia; changed course in 2022

KEY POINTS In 2010, Merck requested to add ‘depression’ to adverse events in the Propecia label. A safety group within FDA concurred, and also recommended adding ‘suicidal thoughts and behavior.’ FDA’s dermatology products group did not support adding a suicidality warning. Only ‘depression’ was added to the label in 2011. Over a decade later, in … Read more

A tweeted rebuttal to yet another analysis of finasteride adverse events: Nguyen et al, 2022

A thread originally posted on Twitter is reproduced below. For an in-depth version, see the essay Context matters. See also a critique of three previous papers with similar designs, findings and conclusions. Twitter thread Nguyen et al, 2022 is the fourth analysis of adverse events of finasteride to appear since 2018. All four studies play … Read more

How was finasteride invented?

Although finasteride came on the market in the 1990s, the science that led to its development began two decades earlier. The rationale for the drug emerged from a study of a unique group of people in a remote village in the Dominican Republic called Las Salinas. Locals there have long known about children who follow … Read more

Merck’s Propecia business

HIGHLIGHTS Estimated Propecia revenue from 1999–2015: $5.2 billion Rough estimate of operating profit from Propecia: $4.2 billion Merck received FDA approval for Propecia (finasteride 1 mg/day) in December 1997. Sales in the first year of marketing were reported to be $76 million. The peak years were 2010–2011, when Merck reported $447 million in Propecia sales … Read more

Since 1994, Merck has been aware of unresolved sexual dysfunction in men who stopped taking finasteride

Six months after discontinuing a Phase 3 finasteride trial, a man’s sexual adverse experience was unresolved. There were also 16 men whose drug-related sexual adverse experiences were unresolved at the conclusion of the trial.