TLDR Finasteride, when given in high oral doses to pregnant monkeys, caused genital abnormalities in male fetuses, but not in female fetuses or those exposed to intravenous finasteride.
The study aimed to determine the effects of finasteride, a type 2 5-alpha reductase inhibitor, on fetal development in rhesus monkeys. The researchers treated pregnant monkeys with finasteride and monitored their gestation period. They found that administering a high oral dose of finasteride resulted in external genital abnormalities in male fetuses, such as hypospadias and underdeveloped scrotum. However, no developmental abnormalities were observed in female fetuses or in fetuses exposed to the intravenous formulation of finasteride. The study concluded that the rhesus monkey is a suitable model for assessing the safety of 5-alpha reductase inhibitors during pregnancy.
136 citations,
March 1996 in “Journal of the American Chemical Society” Finasteride effectively blocks enzyme causing male pattern baldness.
70 citations,
June 1993 in “Biochemistry” Finasteride slowly binds to 5-alpha-reductase, affecting enzyme stability and inhibitor potency.
86 citations,
March 1993 in “Toxicology and Applied Pharmacology” Finasteride affects male rat genitalia development, causing abnormalities during specific pregnancy days.
1040 citations,
October 1992 in “The New England Journal of Medicine” Finasteride effectively treats BPH but may increase sexual dysfunction risk.
28 citations,
January 1991 in “Reproductive Toxicology” Finasteride temporarily lowers male rat fertility without affecting libido.
37 citations,
January 1991 in “Reproductive Toxicology” Finasteride reduces male rat fertility by causing issues with copulatory plug formation.
122 citations,
July 1990 in “Teratology” Finasteride exposure in pregnancy causes genital abnormalities in male rats.
147 citations,
April 1990 in “The Journal of Clinical Endocrinology and Metabolism” Finasteride safely lowers DHT levels without affecting testosterone.
193 citations,
August 1985 in “Endocrinology” Different animals have unique versions of the enzyme that changes testosterone into another hormone, which is important for creating effective treatments for prostate and hair loss conditions.
30 citations,
August 1992 in “The Journal of Clinical Endocrinology and Metabolism” Finasteride doesn't affect hormone levels in normal men.
