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

March 1996 in “ Journal of the American Chemical Society ”

Herbert G. Bull, Margarita Garcia-Calvo, Stefan Andersson, Walter F. Baginsky, H. Karen Chan, Dina E. Ellsworth, Randall F. Miller, Ralph A. Stearns, Raman K. Bakshi, Gary H. Rasmusson, Richard M. Tolman, Robert C. Myers, and John W. Kozarich, Georgianna Harris

finasteride steroid 5α-reductase dihydrotestosterone DHT male pattern baldness androgenic alopecia benign prostatic hyperplasia Propecia Proscar

TLDR Finasteride effectively blocks enzyme causing male pattern baldness.

This scientific paper from 1996 explores the mechanism by which finasteride inhibits human steroid 5α-reductase, an enzyme involved in the production of dihydrotestosterone (DHT), which is linked to male pattern baldness. The study found that finasteride acts as a potent bisubstrate analog inhibitor, forming a noncovalent complex with the enzyme that is irreversible and has a dissociation constant of K₁* ≤ 3 × 10-13 M. The study provides important insights into the mechanism of action of finasteride, which is commonly used to treat male pattern baldness and benign prostatic hyperplasia.

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Research cited in this study

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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 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.

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.

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community Can I still save my hairline at age of 15?

Kuba in General 532 upvotes 4 months ago

A 15-year-old is concerned about hair loss, possibly at Norwood 2 or 3, and is using shampoos and conditioners recommended by a trichologist. Suggestions include considering topical minoxidil and consulting a doctor about topical anti-DHT treatments like finasteride or RU58841, but avoiding 5-alpha-reductase inhibitors at this age.

community 28M experiencing thinning - first timer here, please help

cgem753 in Treatments 370 upvotes 3 months ago

A 28-year-old male experiencing hair thinning is considering minoxidil and finasteride. Minoxidil helps regrow hair, while finasteride prevents further loss; both are usually lifelong treatments.

community risks with finasteride and dutasteride

in Research/Science 143 upvotes 8 months ago

Finasteride and dutasteride have potential risks, including post-finasteride syndrome, but are commonly used for hair loss. RU58841, minoxidil, and needling are suggested as alternatives, though all treatments carry risks.

community Finasteride only reduces scalp DHT by ~40%. Why does it work?

in Finasteride/Dutasteride 37 upvotes 2 years ago

How Finasteride and Dutasteride help reduce hair loss by reducing the amount of DHT in scalp areas, as well as discussing factors such as sensitivity to DHT, 5α-reductase expression in different parts of the hair follicle, and scalp tension.

community No, Finasteride as a treatment for MPB was not an "accident"

in Research/Science 106 upvotes 4 years ago

Finasteride was intentionally developed to treat BPH and later approved for male pattern baldness (MPB) due to its 5AR inhibition effects. The delay in MPB approval was due to concerns about off-label use for female hirsutism and the prioritization of treating a more debilitating condition.

community How to know if shedding is from tren or minoxidil?

in Minoxidil 5 upvotes 1 year ago

The user started using trenbolone and minoxidil simultaneously and experienced increased hair shedding, unsure which is causing it. Replies suggest both drugs could cause hair loss, with one advising to stop trenbolone to protect hair and another indicating minoxidil is unlikely the cause due to the timing.

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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

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

Finasteride effectively blocks enzyme causing male pattern baldness.