Last reviewed · How we verify
Propecia (finasteride)
Selective type II 5-alpha-reductase inhibitor that blocks conversion of testosterone to dihydrotestosterone (DHT), treating BPH and male pattern hair loss.
Finasteride is a 5-alpha-reductase inhibitor developed by Merck, approved in 1992. Marketed as Proscar (BPH) and Propecia (hair loss). Available generically.
At a glance
| Generic name | finasteride |
|---|---|
| Also known as | Propecia, Proscar |
| Sponsor | Merck & Co. |
| Drug class | 5-alpha-reductase inhibitor |
| Target | 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 1, Cytochrome P450 2C19, Cytochrome P450 2C9 |
| Modality | Small molecule |
| Therapeutic area | Urology |
| Phase | FDA-approved |
| First approval | 1992-06-19 (United States) |
Mechanism of action
Finasteride blocks the conversion of testosterone to DHT, the androgen primarily responsible for prostate growth and androgenetic alopecia. At 5mg (Proscar) it shrinks the prostate in BPH; at 1mg (Propecia) it treats male pattern baldness. Teratogenic — women who are or may become pregnant must not handle crushed tablets.
Approved indications
- Benign prostatic hyperplasia
- Male Patterned Baldness
Common side effects
- Decreased Libido
- Erectile Dysfunction
- Ejaculation Disorder
- Decreased Volume of Ejaculate
- Discontinuation due to drug-related sexual adverse experiences
Key clinical trials
- A Prospective Multicentric Open Label Randomized Bio-Interventional Phase I/II Pilot Study To Evaluate The Safety And Efficacy Of Autologous Human Platelet Lysate (HPL) For Treatment Of Androgenetic A (Phase 1)
- Kinetics of the Finasteride Prostate Induced Apoptosis (Phase 4)
- A Phase III, Randomized Clinical Trial to Study the Safety and Efficacy of MK-906 (Finasteride) and Tamsulosin Administered Either Alone or Concomitantly in Patients With Benign Prostatic Hyperplasia (Phase 3)
- Prostate Medication, Metabolism and Gut Microbiota (Phase 4)
- A Randomized, Phase IIB, Double Blind, Placebo Controlled, Multicenter, Pre-surgical, Window-of-opportunity Trial of Finasteride Vs. Low-dose Flutamide Vs. Placebo in Prostate Cancer (2F Trial) (Phase 2)
- A Multicenter, Randomized, Double-blind, Placebo-controlled Phase II Clinical Trial to Evaluate the Efficacy and Safety of CG2001 in Chinese Adult Male Participants With Androgenetic Alopecia (Phase 2)
- Study Evaluating the Association of CAG Repeat Polymorphisms and Finasteride Response in Women With Androgenetic Alopecia (Phase 1)
- Switch Study: Are There Any Measurable Differences When Switching Patients on Finasteride Therapy to Dutasteride? (Phase 4)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |