Propecia Litigation Overview

Black Law, PC is committed to representing men who are struggling with the sexual side effects of Propecia.


The development of finasteride, the active ingredient in Merck’s Propecia/Proscar, began in the Dominican Republic in 1974.  A young endocrinologist, Dr. Julianne Imperato-McGinley published her research findings on a pseudo-hermaphroditic family she had studied in the Dominican Republic.  She noticed the males in the family had a genetic deficiency of the Type II 5-alpha reductase enzyme, their prostate glands were 1/10th their normal size, and that as adults, none of the males ever went bald.

In 1980, Merck scientists took note of Dr. Imperato-McGinley’s work and created a chemical compound (finasteride) which mimicked the 5-alpha reductase enzyme deficiency.  Merck’s first finasteride patent was approved in 1988.  Initially, Merck was attempting to target older men with enlarged prostates.

The 5mg dose of Finasteride (Proscar) was approved by the FDA in 1992 for the treatment of benign prostate hyperplasia (BPH).  The patent for Proscar expired on June 19, 2006.  Proscar was commonly prescribed off-label for hair loss and patients were routinely told to cut the pill into four parts.

The 1mg dose of Finasteride (Propecia) was approved by the FDA in 1997 for the treatment of male pattern baldness (androgenic alopecia).  The patent for Propecia expired on November 5, 2013.

Mechanism of Action

In males, the two most important androgens for normal sexual function are testosterone and dihydrotestosterone (DHT).  Testosterone is the weaker of the two androgens.  DHT is directly responsible for the shrinking of the hair follicles leading to hair loss.

Finasteride interacts with the production of testosterone in the body.  Normally, testosterone functions as a pro-hormone.  A pro-hormone is a precursor of another hormone and usually has minimal hormonal effect by itself.  Testosterone is converted in the body by the 5-Alpha Reductase (5AR) enzyme into DHT.

Finasteride blocks the conversion of testosterone into DHT.  Normally, testosterone binds to the 5AR enzyme in the reproductive tissues where it is converted to DHT.  The chemical structure of finasteride is similar to the chemical structure of testosterone.  Finasteride chemically and irreversibly combines with the 5AR enzyme and inhibits the conversion of testosterone into DHT.  By limiting the amount of DHT in the blood stream, finasteride reduces the damaging effects of DHT on the hair follicles and encourages hair growth.

Side Effects and Warnings

There are several possible side effects of Propecia including, infertility, erectile dysfunction, impotence, diminished libido, decreased sperm production, breast enlargement, breast cancer, shrinkage of the genitalia, and decreased ejaculate volume.

In 2006, the Swedish Medical Products Agency began an investigation of persistent sexual side effects which continued even after users stopped taking Propecia.  By 2009, Sweden concluded that Propecia could lead to permanent sexual dysfunction.  In response, Merck added “persistence of erectile dysfunction after discontinuation of treatment with Propecia” to its warning label in Sweden, Italy, and the United Kingdom.

However, it was not until June of 2011 that Merck adding the warning to its U.S. label.  In the final pages under “Post Marketing Experience”, the label states:  “breast tenderness and enlargement; depression; hypersensitivity reactions including rash, pruritus, urticaria, and swelling of the lips and face; testicular pain; erectile dysfunction that continued after discontinuation of treatment; and male breast cancer.”

Additionally, Merck modified the July 2011 Patient Insert to say:

“What are the possible side effects of Propecia?…In clinical studies, side effects from Propecia were uncommon and did not affect most men.  A small number of men experienced certain sexual side effects.  These men reported one or more of the following:  less desire for sex; difficulty in achieving an erection; and, a decrease in the amount of semen. Each of these side effects occurred in less than 2% of men. These side effects went away in men who stopped taking Propecia.  They also disappeared in most men who continued taking Propecia…In general use, the following have been reported:  breast tenderness and enlargement; depression; allergic reactions including rash, itching, hives, and swelling of the lips and face; problems with ejaculation; testicular pain; difficulty in achieving an erection that continued after stopping the medication; and in rare cases, male breast cancer.”

In April of 2012, Merck finally modified the Propecia label and Patient Insert to disclose the risk of permanent sexual dysfunction and “infertility and/or poor seminal quality”.

Pending Litigation

There are two epicenters of Propecia litigation:  state court in Middlesex County, New Jersey and in the federal MDL in the Eastern District of New York.

New Jersey Litigation

All New Jersey Propecia cases have been consolidated in Middlesex County in front of the Honorable Jessica R. Mayer.  There are over 350 cases pending in Middlesex County.

Federal MDL-MDL 2331 In re Propecia (Finasteride) Products Liability Litigation

There are over 700 cases pending in the Brooklyn Division of the Eastern District of New York.  The cases are pending before the Honorable John Gleeson.  Judge Gleeson is a Bronx native, received his B.A. from Georgetown University and his J.D. from the University of Virginia.  He clerked for Boyce Martin on the 6th Circuit and was in private practice at Cravath, Swaine & Moore from 1981-1985.  He was an assistant U.S. Attorney in the Eastern District of New York from 1985 to 1994 where he was noted for his prosecution of Mafia cases, including the prosecution of John Gotti.

Procedural Posture

The MDL is still in its early stages.  Although the PSC was appointed in June of 2012, the parties have only recently agreed to a Plaintiff Profile Form (Fact Sheet).  Fact Sheets are due within 135 days of direct filing or transfer to the MDL.

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