• A proposed explanation of lasting dysfunctions after use of finasteride or dutasteride

    Men who previously took finasteride and dutasteride have reported sexual dysfunction, anxiety, depression, cognitive problems and other dysfunctions which have continued long after stopping the drug. This paper proposes an explanation for how these dysfunctions may develop.

  • Context matters: a rebuttal to yet another analysis of adverse events of finasteride

    This post responds to a recent research letter: Nguyen DD, et al. Disproportional signal of sexual dysfunction reports associated with finasteride use in young men with androgenetic alopecia: A pharmacovigilance analysis of VigiBase. J Am Acad Dermatol. 2022. doi:10.1016/j.jaad.2022.03.037 A recent paper by Nguyen et al. in the Journal of the American Academy of Dermatology analyzes sexual adverse … 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.

  • The Merck files, part 3: Propecia lawsuits

    Filings from lawsuits alleging persistent adverse effects of Propecia and Proscar in various jurisdictions in the United States and Canada, dating from 2011 to 2021.

  • The Merck files, part 2: Merck responds to regulatory concerns about persistent adverse effects of Propecia

    These documents from 2006–2009 concern Merck’s response to postmarketing reports of persistent erectile dysfunction, male infertility and depressive disorders, among other adverse events, associated with use of finasteride. In 2006, the Swedish Medical Products Agency asked Merck for an analysis of all adverse events affecting the male reproductive system which persisted after stopping Propecia. In … Read more

  • The Merck files, part 1: An inside look at the development of Propecia

    Merck first developed finasteride for benign prostatic hyperplasia, a condition typically found in men aged 55 and older. After receiving approval for the application in 1992 and bringing the drug to market as Proscar, Merck decided to seek approval of finasteride for male pattern hair loss—to be branded as Propecia. In a 1994 memo below, … Read more

  • The Merck files: a series

    Selected documents from Propecia litigation were released by court order in 2021. This series walks through these documents, revealing Merck’s strategy for discounting safety concerns arising from clinical trials and adverse event reports. The collection is divided into three parts: 1. An inside look at the development of Propecia (1994–2001) 2. Merck responds to regulatory … Read more

  • When medical treatment brings on disease: iatrogenic disorders

    Those who have lasting dysfunctions after taking finasteride or dutasteride are not the only ones whose lives have been altered for the worse because of a medical treatment. This post summarizes diseases and conditions that may arise from medical treatments: five in dermatology, four in psychiatry and one in general medicine. ↓ Jump to the … Read more

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Harvesters by Pieter Breughel the Elder, 1565 (via Met Museum Open Access)