Finasteride: The First 5α-Reductase Inhibitor

July 1993 in “ Pharmacotherapy ”

S. Lynn Sudduth, Michael J. Koronkowski

finasteride 5α-reductase dihydrotestosterone DHT male pattern baldness benign prostatic hyperplasia BPH prostate-specific antigen PSA Propecia

TLDR Finasteride treats enlarged prostate and baldness, but may cause limited urinary improvement and sex-related side effects.

Finasteride is a drug that inhibits the enzyme 5α-reductase, which converts testosterone to dihydrotestosterone (DHT). It is used to treat benign prostatic hyperplasia (BPH) and male pattern baldness. Studies have shown that it can effectively reduce DHT levels and prostate volume in patients with BPH, but its efficacy in improving urinary symptoms is limited. Finasteride may also reduce the level of prostate-specific antigen (PSA), which can interfere with diagnostic screening for prostate cancer. The drug has low adverse events, but may cause sex-related side effects. Its potential use in treating other DHT-mediated disorders remains investigational.

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Research cited in this study

10 / 10 results

research The Effect of Finasteride in Men with Benign Prostatic Hyperplasia

1040 citations, October 1992 in “The New England Journal of Medicine”

Finasteride effectively treats BPH but may increase sexual dysfunction risk.

research High-Performance Liquid Chromatographic Method for the Determination of Finasteride in Human Plasma at Therapeutic Doses

19 citations, May 1991 in “Journal of Chromatography B: Biomedical Sciences and Applications”

Reliable method detects finasteride in human plasma at low doses.

research 5α-Metabolism in Finasteride-Treated Subjects and Male Pseudohermaphrodites with Inherited 5α-Reductase Deficiency

8 citations, January 1991 in “European Urology”

Finasteride lowers DHT levels and raises testosterone in a dose-dependent way.

research Reversible Decreases of Fertility in Male Sprague-Dawley Rats Treated Orally with Finasteride, a 5α-Reductase Inhibitor

28 citations, January 1991 in “Reproductive Toxicology”

Finasteride temporarily lowers male rat fertility without affecting libido.

research Decreased Fertility in Male Rats Administered the 5α-Reductase Inhibitor, Finasteride, Due to Deficits in Copulatory Plug Formation

37 citations, January 1991 in “Reproductive Toxicology”

Finasteride reduces male rat fertility by causing issues with copulatory plug formation.

research The Clinical Development of a 5α-Reductase Inhibitor, Finasteride

211 citations, November 1990 in “The Journal of Steroid Biochemistry and Molecular Biology”

Finasteride effectively treats BPH, but needs more trials to understand potential.

research External Genitalia Abnormalities in Male Rats Exposed In Utero to Finasteride, a 5α-Reductase Inhibitor

122 citations, July 1990 in “Teratology”

Finasteride exposure in pregnancy causes genital abnormalities in male rats.

research Effects of Finasteride (MK-906), a 5α-Reductase Inhibitor, on Circulating Androgens in Male Volunteers

147 citations, April 1990 in “The Journal of Clinical Endocrinology and Metabolism”

Finasteride safely lowers DHT levels without affecting testosterone.

C19 and C21 5β/5α Metabolite Ratios in Subjects Treated with the 5α-Reductase Inhibitor Finasteride: Comparison of Male Pseudohermaphrodites with Inherited 5α-Reductase Deficiency

research C19 and C21 5β/5α Metabolite Ratios in Subjects Treated with the 5α-Reductase Inhibitor Finasteride: Comparison of Male Pseudohermaphrodites with Inherited 5α-Reductase Deficiency

55 citations, March 1990 in “The Journal of Clinical Endocrinology and Metabolism”

Finasteride may treat baldness but less effective for those with 5α-reductase deficiency.

research Species Differences in Prostatic Steroid 5α-Reductases of Rat, Dog, and Human

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.

Related Research

3 / 3 results

research Discovery of a Novel Hybrid from Finasteride and Epristeride as 5α-Reductase Inhibitor

18 citations, January 2011 in “Bioorganic & Medicinal Chemistry Letters”

New hybrid compound found to effectively prevent hair loss.

Mechanism-Based Inhibition of Human Steroid 5α-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor

research Mechanism-Based Inhibition of Human Steroid 5α-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor

136 citations, March 1996 in “Journal of the American Chemical Society”

Finasteride effectively blocks enzyme causing male pattern baldness.

Synthesis and In Vitro Evaluation of 4-Substituted N-(1,1-Dimethylethyl)-3-Oxo-4-Androstene-17β-Carboxamides as 5α-Reductase Inhibitors and Antiandrogens

research Synthesis and In Vitro Evaluation of 4-Substituted N-(1,1-Dimethylethyl)-3-Oxo-4-Androstene-17β-Carboxamides as 5α-Reductase Inhibitors and Antiandrogens

12 citations, April 1995 in “Journal of Medicinal Chemistry”

The new compounds moderately block a specific enzyme and strongly counteract a male hormone, suggesting potential for treating certain male-related health conditions.

Finasteride: The First 5α-Reductase Inhibitor

Research cited in this study

research The Effect of Finasteride in Men with Benign Prostatic Hyperplasia

research High-Performance Liquid Chromatographic Method for the Determination of Finasteride in Human Plasma at Therapeutic Doses

research 5α-Metabolism in Finasteride-Treated Subjects and Male Pseudohermaphrodites with Inherited 5α-Reductase Deficiency

research Reversible Decreases of Fertility in Male Sprague-Dawley Rats Treated Orally with Finasteride, a 5α-Reductase Inhibitor

research Decreased Fertility in Male Rats Administered the 5α-Reductase Inhibitor, Finasteride, Due to Deficits in Copulatory Plug Formation

research The Clinical Development of a 5α-Reductase Inhibitor, Finasteride

research External Genitalia Abnormalities in Male Rats Exposed In Utero to Finasteride, a 5α-Reductase Inhibitor

research Effects of Finasteride (MK-906), a 5α-Reductase Inhibitor, on Circulating Androgens in Male Volunteers

research C19 and C21 5β/5α Metabolite Ratios in Subjects Treated with the 5α-Reductase Inhibitor Finasteride: Comparison of Male Pseudohermaphrodites with Inherited 5α-Reductase Deficiency

research Species Differences in Prostatic Steroid 5α-Reductases of Rat, Dog, and Human

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Related Research

research Discovery of a Novel Hybrid from Finasteride and Epristeride as 5α-Reductase Inhibitor

research Mechanism-Based Inhibition of Human Steroid 5α-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor

research Synthesis and In Vitro Evaluation of 4-Substituted N-(1,1-Dimethylethyl)-3-Oxo-4-Androstene-17β-Carboxamides as 5α-Reductase Inhibitors and Antiandrogens