Are Propecia and Proscar the same medication?

They contain the same active ingredient, finasteride, at 1 mg and 5 mg, and hold separate FDA approvals: Propecia for male pattern hair loss in men, Proscar for an enlarged prostate. They are the same molecule under two labels, not the same product.

Can Proscar be used for hair loss?

Its label does not cover hair loss, and it describes one dose only, 5 mg once a day for benign prostatic hyperplasia. What a prescriber decides in an individual case is outside what this page can report, because it is outside what the document states.

Do both carry the same warnings?

Largely, and with one difference in wording. Both contraindicate use in pregnancy, both instruct that broken tablets not be handled by anyone pregnant, and both warn about lowered PSA and about high-grade prostate cancer. On that last point Proscar attributes the risk to itself and Propecia attributes it to the class of 5-alpha reductase inhibitors.

Finasteride is available as a generic at both strengths, so brand pricing is not the whole picture, and neither label discusses cost. Where a pharmacy acquisition cost exists in the CMS data it is shown in the table above; that figure is what pharmacies pay, not what a person pays at a counter.

Comparison

Propecia vs Proscar

Propecia

FINASTERIDE

Approved forMale pattern hair loss, in men only

Covers hair loss

Organon LLCLabel version 9, effective 14 October 2024

Proscar

FINASTERIDE

Approved forEnlarged prostate

Not hair loss

Organon LLCLabel version 9, effective 18 March 2026

Each stripe is one section of the label, each division in a stripe one entry in that section.

Reference information, not medical advice

This page is a reference, not medical advice. It reports what the FDA-approved label states and links to that label. It does not tell anyone what to take, and it cannot replace a conversation with a doctor or pharmacist who knows the person's history.

Propecia and Proscar contain the same active ingredient, finasteride, at different strengths, and hold separate FDA approvals for different conditions. That is the whole of the difference between them, and it is the reason the two names are so often confused.

Side by side, straight from the labels

From the FDA label

This table is generated from the two source labels, not typed out by hand, so it cannot drift from what the regulator approved.

Label section	PropeciaFINASTERIDE	ProscarFINASTERIDE
Active ingredient	FinasterideType II 5-alpha reductase inhibitor	FinasterideType II 5-alpha reductase inhibitor
Approved for	Male pattern hair loss, in men only	Enlarged prostate
Supply	Prescription	Prescription
What pharmacies payAcquisition cost, not retail	$3.78 per tablet, capsule or pen, brand	$5.72 per tablet, capsule or pen, brand
Boxed warning	None	None
What the FDA approved it for	Efficacy in bitemporal recession has not been established. PROPECIA is not indicated for use in women. PROPECIA is a 5α-reductase inhibitor indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY.	PROSCAR, is a 5α-reductase inhibitor, indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to: Improve symptoms Reduce the risk of acute urinary retention Reduce the risk of the need for surgery including transurethral resection of the prostate (TURP) and prostatectomy. PROSCAR administered in combination with the alpha-blocker doxazosin is indicated to reduce the risk of symptomatic progression of BPH (a confirmed ≥4 point increase in American Urological Association (AUA) symptom score). Limitations of Use: PROSCAR is not approved for the prevention of prostate cancer.
Forms and strengths	PROPECIA tablets (1 mg) are tan, octagonal, film-coated convex tablets with "stylized P" logo on one side and PROPECIA on the other. 1 mg tablets.	5-mg blue, modified apple-shaped, film-coated tablets, with the code MSD 72 on one side and PROSCAR on the other. 5-mg film-coated tablets.
How the label says it is taken	PROPECIA may be administered with or without meals. The recommended dose of PROPECIA is one tablet (1 mg) taken once daily. In general, daily use for three months or more is necessary before benefit is observed. Continued use is recommended to sustain benefit, which should be re-evaluated periodically.	PROSCAR may be administered with or without meals. Monotherapy: One tablet (5 mg) taken once a day. Combination with Doxazosin: One tablet (5 mg) taken once a day in combination with the alpha-blocker doxazosin.
Most common adverse reactions	most common adverse reactions, reported in ≥1% of patients treated with PROPECIA and greater than in patients treated with placebo are: decreased libido, erectile dysfunction and ejaculation disorder.	The drug-related adverse reactions, reported in ≥1% in patients treated with PROSCAR and greater than in patients treated with placebo over a 4-year study are: impotence, decreased libido, decreased volume of ejaculate, breast enlargement, breast tenderness and rash.
Warnings and precautions	PROPECIA is not indicated for use in women or pediatric patients. Women should not handle crushed or broken PROPECIA tablets when they are pregnant or may potentially be pregnant due to potential risk to a male fetus. PROPECIA causes a decrease in serum PSA levels. Any confirmed increase in PSA while on PROPECIA may signal the presence of prostate cancer and should be evaluated, even if those values are still within the normal range for men not taking a 5α-reductase inhibitor. 5α-reductase inhibitors may increase the risk of high-grade prostate cancer.	PROSCAR reduces serum prostate specific antigen (PSA) levels by approximately 50%. However, any confirmed increase in PSA while on PROSCAR may signal the presence of prostate cancer and should be evaluated, even if those values are still within the normal range for men not taking a 5α-reductase inhibitor. PROSCAR may increase the risk of high-grade prostate cancer. Females should not handle crushed or broken PROSCAR tablets when they are pregnant or may potentially be pregnant due to potential risk to a male fetus.
Contraindications	PROPECIA is contraindicated in the following: Pregnancy. Finasteride use is contraindicated in women when they are or may potentially be pregnant. Because of the ability of Type II 5α-reductase inhibitors to inhibit the conversion of testosterone to 5α-dihydrotestosterone (DHT), finasteride may cause abnormalities of the external genitalia of a male fetus of a pregnant woman who receives finasteride. If this drug is used during pregnancy, or if pregnancy occurs while taking this drug, the pregnant woman should be apprised of the potential hazard to the male fetus. In female rats, low doses of finasteride administered during pregnancy have produced abnormalities of the external genitalia in male offspring.	PROSCAR is contraindicated in the following: Hypersensitivity to any component of this medication. Finasteride use is contraindicated in females when they are or may potentially be pregnant. Because of the ability of Type II 5α-reductase inhibitors to inhibit the conversion of testosterone to 5α-dihydrotestosterone (DHT), finasteride may cause abnormalities of the external genitalia of a male fetus of a pregnant female who receives finasteride. If this drug is used during pregnancy, or if pregnancy occurs while taking this drug, the pregnant female should be apprised of the potential hazard to the male fetus. In female rats, low doses of finasteride administered during pregnancy have produced abnormalities of the external genitalia in male offspring.
Drug interactions	Cytochrome P450-Linked Drug Metabolizing Enzyme System No drug interactions of clinical importance have been identified. Finasteride does not appear to affect the cytochrome P450-linked drug-metabolizing enzyme system. Compounds that have been tested in man include antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found. Other Concomitant Therapy Although specific interaction studies were not performed, finasteride doses of 1 mg or more were concomitantly used in clinical studies with acetaminophen, acetylsalicylic acid, α-blockers, analgesics,...	Cytochrome P450-Linked Drug Metabolizing Enzyme System No drug interactions of clinical importance have been identified. Finasteride does not appear to affect the cytochrome P450-linked drug metabolizing enzyme system. Compounds that have been tested in man have included antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found. Other Concomitant Therapy Although specific interaction studies were not performed, PROSCAR was concomitantly used in clinical studies with acetaminophen, acetylsalicylic acid, α-blockers, angiotensin-converting enzyme (ACE)...
Label version	14 October 2024	18 March 2026

Same molecule, two strengths, two approvals

Written by us

Propecia is a 1 mg tablet approved for male pattern hair loss, and its label states that it is indicated in men only. Proscar is a 5 mg tablet approved for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, to improve symptoms, reduce the risk of acute urinary retention and reduce the risk of needing surgery.

Neither label mentions the other product, and neither presents itself as a stronger or weaker version of anything. They are two separate documents that happen to describe the same molecule.

Both labels describe the same mechanism

Written by us

Both documents describe finasteride as a competitive and specific inhibitor of type II 5-alpha reductase, the enzyme that converts testosterone into dihydrotestosterone. The Proscar label goes on to say that the development and enlargement of the prostate gland depends on that hormone. The Propecia label sets out the same enzymology without the prostate framing.

The mechanism being identical is exactly why the two products get discussed together, and it is also why the difference between them is regulatory rather than pharmacological: what changes is the dose the FDA reviewed and the condition it reviewed it for.

The pregnancy instruction is the same in both

Written by us

Both labels contraindicate finasteride in women who are or may be pregnant, on the same stated grounds: inhibiting the conversion of testosterone to dihydrotestosterone may cause abnormalities of the external genitalia of a male fetus. Both go further and instruct that crushed or broken tablets should not be handled by anyone pregnant or possibly pregnant.

This is the one point where the two documents say substantially the same thing, and it applies whichever tablet is in the house.

Both warn about prostate cancer, and word it differently

Written by us

Both labels carry a warning about high-grade prostate cancer, and the wording is not identical. The Proscar label states that Proscar may increase the risk of high-grade prostate cancer. The Propecia label states that 5-alpha reductase inhibitors may increase that risk, attributing it to the class rather than to the product.

Both also warn that the medication lowers prostate-specific antigen, which matters because PSA is used to look for prostate cancer. Here only one label gives a figure: Proscar states a reduction of approximately 50 percent, while the Propecia label says that it causes a decrease without quantifying it. Both instruct that any confirmed rise in PSA during treatment be evaluated even when the value still looks normal.

The reported adverse reactions overlap but are not one list

Written by us

Both labels use the same reporting threshold, reactions in at least 1 percent of treated patients and more often than with placebo. The Propecia list is decreased libido, erectile dysfunction and ejaculation disorder. The Proscar list is impotence, decreased libido, decreased volume of ejaculate, breast enlargement and breast tenderness, drawn from a four-year study.

The two lists come from different trials in different populations at different doses, so the difference between them is not a measured difference between the products.

What neither label covers

Written by us

Splitting a 5 mg tablet to approximate the 1 mg dose is a well known practice, and neither document describes it. The Proscar label gives one dosing instruction, one tablet of 5 mg once a day, and the Propecia label gives one tablet of 1 mg once a day. Nothing in either says what happens between those two numbers, so this page does not fill that gap.

The Propecia label does state two things about time that the Proscar label has no counterpart for: that daily use for three months or more is generally needed before benefit is seen, and that continued use is recommended to sustain it, with the benefit re-evaluated periodically.

Common questions

Written by us

Are Propecia and Proscar the same medication?: They contain the same active ingredient, finasteride, at 1 mg and 5 mg, and hold separate FDA approvals: Propecia for male pattern hair loss in men, Proscar for an enlarged prostate. They are the same molecule under two labels, not the same product.
Can Proscar be used for hair loss?: Its label does not cover hair loss, and it describes one dose only, 5 mg once a day for benign prostatic hyperplasia. What a prescriber decides in an individual case is outside what this page can report, because it is outside what the document states.
Do both carry the same warnings?: Largely, and with one difference in wording. Both contraindicate use in pregnancy, both instruct that broken tablets not be handled by anyone pregnant, and both warn about lowered PSA and about high-grade prostate cancer. On that last point Proscar attributes the risk to itself and Propecia attributes it to the class of 5-alpha reductase inhibitors.
Which is cheaper?: Finasteride is available as a generic at both strengths, so brand pricing is not the whole picture, and neither label discusses cost. Where a pharmacy acquisition cost exists in the CMS data it is shown in the table above; that figure is what pharmacies pay, not what a person pays at a counter.

Sources

Every fact above comes from one of these documents. The date is the effective date of the label version this page was built from.

FDA prescribing information for Propecia
Organon LLC. Label version 9, effective 14 October 2024.
Full label on DailyMed Approval record NDA020788
FDA prescribing information for Proscar
Organon LLC. Label version 9, effective 18 March 2026.
Full label on DailyMed Approval record NDA020180

Other comparisons in this category

Page last updated: 10 August 2026

Compiled by the HealthyStudy editorial team from FDA source documents. No medical reviewer is credited on this page, because none reviewed it.