What is the difference between Propecia and Proscar?

Strength, indication and population. Propecia is finasteride 1 mg once daily, approved for male pattern hair loss in men only, with evidence from men aged 18 to 41. Proscar is finasteride 5 mg once a day, approved for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, with evidence from men aged 45 to 78. The Propecia label refers to the 5 mg dose in its own words as "5 times the dose of PROPECIA".

Can a 5 mg finasteride tablet be cut into quarters?

No label says. The word "split" appears in no finasteride label, both tablets are declared in their structured product data as one piece — unscored — and FDA states that a tablet approved for splitting says so in its HOW SUPPLIED section and carries a score mark. Neither applies here. What the labels do say is that the coating is what prevents contact with the active ingredient, "provided that the tablets have not been broken or crushed", so breaking one removes the barrier the pregnancy warning relies on.

Why can a pregnant woman not touch the tablet?

She can touch an intact one — that is exactly what the label says. "PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed." The risk is a broken or crushed tablet: finasteride may cause abnormalities of the external genitalia of a male fetus, and pregnancy is a contraindication. If contact with a broken tablet does occur, the label directs washing the area immediately with soap and water.

How long does Propecia take to work?

The label's own expectation is three months at minimum: "In general, daily use for three months or more is necessary before benefit is observed." The trial timepoints run further out — a 107-hair difference from placebo within a 1-inch circle at 12 months, 138 hairs at 2 years and 277 hairs at 5 years, with the label noting that maximum improvement in hair count compared to baseline was achieved during the first 2 years and the gap kept widening mainly because the placebo group kept declining.

What happens if you stop taking it?

The label states it in one sentence: "Withdrawal of treatment leads to reversal of effect within 12 months." Section 14.1 gives the study it came from: "A change of treatment from PROPECIA to placebo (n=48) at the end of the initial 12 months resulted in reversal of the increase in hair count 12 months later, at 24 months." Continued use is what the label recommends to sustain benefit, with periodic re-evaluation.

Does Propecia affect a PSA test?

Yes, and by less than people expect at this dose. In men aged 18 to 41 the mean serum PSA fell from 0.7 ng/mL at baseline to 0.5 ng/mL at month 12. The familiar instruction to double a PSA result comes from the 5 mg product, where levels are decreased by approximately 50% in older men with benign prostatic hyperplasia. The label’s standing advice applies at either dose: any confirmed increase from the lowest PSA value while on finasteride should be evaluated, even within the normal range.

How common are sexual side effects on 1 mg?

In year 1 of the Propecia trials, drug-related reactions at 1% or more were decreased libido 1.8% versus 1.3% on placebo, erectile dysfunction 1.3% versus 0.7% and ejaculation disorder 1.2% versus 0.7%, with the incidence of each falling to 0.3% or less by the fifth year. The much-quoted 8.1% impotence figure is from PLESS, a four-year study of the 5 mg tablet in men aged 45 to 78, where the placebo rate was 3.7%.

Is Propecia approved for women?

No, and the label refuses it three times over. Section 1 states it is indicated "in MEN ONLY" and that "PROPECIA is not indicated for use in women". Section 4 makes pregnancy a contraindication. And section 14.2 reports the study: "In a study involving 137 postmenopausal women with androgenetic alopecia who were treated with PROPECIA (n=67) or placebo (n=70) for 12 months, effectiveness could not be demonstrated." It is also not indicated in pediatric patients, and clinical efficacy studies did not include anyone aged 65 or over.

Brand — one of two finasteride products

Propecia

Finasteride 1 mg for male pattern hair loss, in MEN ONLY. The same molecule is sold as Proscar at five times the dose for an enlarged prostate — and the label’s only protection for a pregnant woman in the house is the coating on an unbroken tablet.

Molecule: finasteride
Manufacturer: Organon LLC
Products under this name: 1
Last reviewed: September 2026

Why "finasteride" is two medicines, not one at two strengths

Finasteride is approved in the United States twice over, by the same company, for two diseases that have nothing to do with each other. PROPECIA (NDA020788) is 1 mg once daily and is "indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY". PROSCAR (NDA020180) is 5 mg once a day and is indicated for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, to improve symptoms and to reduce the risk of acute urinary retention and of needing surgery. Neither is approved for the other’s indication, and the PROPECIA label refers to 5 mg in its own words as "5 times the dose of PROPECIA".

Because the two tablets differ only in strength, the obvious idea is to buy the 5 mg one and break it up. The labels do not describe that, and the reason is specific rather than general. The protection they offer a pregnant woman who might handle the tablet is the coating itself: "PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed." Break the coating and the stated safeguard is gone. That sentence appears four times in the PROPECIA document — sections 5.1, 8.1, 16 and 17 — and again, almost word for word, on the PROSCAR label and on the generics.

It is worth being precise about what the labels do not say, because the neighbouring drug classes do. The word "split" occurs nowhere in any finasteride label; there is no sentence equivalent to CIALIS’s "Do not split CIALIS tablets". Both finasteride tablets are declared in their structured product data with a score of one piece — that is, unscored — and FDA’s own guidance is that approval to split appears in the HOW SUPPLIED section and is marked by a score on the tablet. Neither is present here. The honest statement is not "you are forbidden to split it"; it is that no label evaluates it, and that breaking the tablet removes the one barrier the label names.

What is true of Propecia and not of finasteride

Each row is something a reader would reasonably assume belongs to the molecule, and does not. These are the facts that change when the brand name on the carton changes, while the drug inside it does not.

Attribute	Propecia	Elsewhere, same molecule
What it is approved to treatOne molecule, two unrelated diseases, two applications. Neither product is approved for the other’s indication, so a hair-loss prescription written against the 5 mg tablet and a prostate prescription written against the 1 mg tablet are both off-label uses of the product in the box.	Male pattern hair loss, and the label puts the population in capitals: "PROPECIA ® is indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY ." It adds that efficacy in bitemporal recession has not been established.	PROSCAR, the 5 mg finasteride tablet, is indicated 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 including TURP and prostatectomy.
The doseA milligram figure alone does not identify a finasteride prescription. It identifies the disease being treated, the age band the evidence comes from, the size of the PSA effect and the adverse reaction rates — all of which change fivefold along with the dose.	The recommended dose of PROPECIA is one tablet (1 mg) taken once daily. One strength, no titration, no maximum stated because only one dose exists.	The recommended dose of PROSCAR is one tablet (5 mg) taken once a day — five times as much, and the PROPECIA label itself describes the 5 mg studies as being run at "5 times the dose of PROPECIA".
Whether the tablet can be divided into the other oneQuartering a 5 mg tablet is the commonest thing people do with finasteride and the one thing neither label addresses. FDA's own position is that "If a tablet is FDA-approved to be split, this information will be printed in the “HOW SUPPLIED” section of the professional label insert and in the patient package insert. Also, the tablet will be scored with a mark indicating where to split it." — neither is present on either product, and breaking the coating removes the barrier the pregnancy warning depends on.	No label describes it. Both finasteride labels are silent on splitting — the word does not occur in either — and both declare a structured SPL score of 1 piece, which is an unscored tablet. What the label does state is what breaking one costs: "PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed."	PROSCAR carries the identical sentence about its own tablet: "PROSCAR tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed." It too is unscored, and its label likewise never uses the word "split".
Who the evidence comes fromThe two age bands do not overlap at all. A man of 55 reading a finasteride trial result is reading about one of two populations, and which one depends on the strength — which is also why the PROPECIA trial caveat matters: "In order to prevent seborrheic dermatitis which might confound the assessment of hair growth in these studies, all men, whether treated with finasteride or placebo, were instructed to use a specified, medicated, tar-based shampoo (Neutrogena T/Gel® Shampoo) during the first 2 years of the studies."	Men aged 18 to 41 with mild to moderate hair loss: "The efficacy of PROPECIA was demonstrated in men (88% Caucasian) with mild to moderate androgenetic alopecia (male pattern hair loss) between 18 and 41 years of age." Section 8.5 adds that clinical efficacy studies did not include subjects aged 65 and over, and that efficacy in the elderly has not been established.	The 5 mg evidence comes from the opposite end of life. PLESS, the four-year controlled study behind PROSCAR, evaluated 3,040 men between the ages of 45 and 78 with symptomatic BPH and an enlarged prostate.
How much it moves PSAThe rule of thumb that you double a PSA result on finasteride comes from the 5 mg product in men with an enlarged prostate. Applying it to a 1 mg result in a man in his thirties is applying a correction ten times larger than the effect the label describes.	A little, in young men: "In clinical studies with PROPECIA (finasteride, 1 mg) in men 18-41 years of age, the mean value of serum prostate specific antigen (PSA) decreased from 0.7 ng/mL at baseline to 0.5 ng/mL at Month 12."	A lot, in older men: "in clinical studies with PROSCAR (finasteride, 5 mg) when used in older men who have benign prostatic hyperplasia (BPH), PSA levels are decreased by approximately 50%."
How often sexual adverse reactions were reportedThe figures most often quoted as "finasteride side effect rates" are roughly six times higher on the 5 mg product than on the 1 mg one, in an older population with a different baseline. Neither set transfers to the other dose.	Year 1 of the PROPECIA trials, drug-related and at 1% or more: decreased libido 1.8% versus 1.3% on placebo, erectile dysfunction 1.3% versus 0.7%, ejaculation disorder 1.2% versus 0.7%. The label adds that the incidence of each fell to 0.3% or less by the fifth year of treatment.	Year 1 of PLESS, on 5 mg: impotence 8.1% versus 3.7% on placebo, decreased libido 6.4% versus 3.4%, decreased volume of ejaculate 3.7% versus 0.8%. In years 2 to 4 there was no significant difference between groups for impotence, decreased libido or ejaculation disorder.
Whose prostate-cancer finding it isThe single most serious safety signal attached to this molecule was generated at a dose this brand does not sell, and the label says so rather than importing it. Reproducing the PCPT figures as "finasteride increases high-grade prostate cancer risk" drops the dose and the hedge at once.	The PROPECIA label reports the Prostate Cancer Prevention Trial result — Gleason 8-10 prostate cancer in 1.8% on finasteride versus 1.1% on placebo — and then hedges it explicitly, because PCPT used 5 mg: "The clinical significance of these findings with respect to use of PROPECIA by men is unknown."	PROSCAR carries the same finding as a warning about its own dose, and adds a Limitation of Use that PROPECIA has no equivalent of: "PROSCAR is not approved for the prevention of prostate cancer."
How the bottle is storedTwo tablets of one molecule from one manufacturer with different environmental instructions — moisture for one, light for the other. Decanting either into a weekly pill organiser leaves the protection the label specifies behind in the bottle.	Room temperature, 15–30 °C, "Keep container closed and protect from moisture", and both package sizes — the 30-count bottle and the 90-count PROPAK — ship with a desiccant.	PROSCAR is stored "at room temperatures below 30°C (86°F). Protect from light and keep container tightly closed", in bottles of 30 and 100, with no desiccant mentioned.

Propecia tablets

Dosage form: Tablet, film coated
Route: Oral, once daily, with or without meals
Marketing category: NDA — NDA020788
Label read: SPL version 9, effective October 14, 2024

What this product is approved to treat

—PROPECIA ® is indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY .
—Efficacy in bitemporal recession has not been established.
—PROPECIA is not indicated for use in women.

The labelled ladder

When	Dose	What the label attaches to this step
Day 1 onward	1 mg once daily	The recommended dose of PROPECIA is one tablet (1 mg) taken once daily. There is no titration, no starting dose distinct from the maintenance dose and no second strength — section 2 Dosage and Administration names one dose and then describes what happens over time at that dose. "PROPECIA may be administered with or without meals."
3 months	1 mg once daily	The earliest the label expects a benefit to be observable. "In general, daily use for three months or more is necessary before benefit is observed." (section 2 Dosage and Administration).
6 months	1 mg once daily	First timepoint at which hair count rose significantly. "In these two studies in men with vertex baldness, significant increases in hair count were demonstrated at 6 and 12 months in men treated with PROPECIA, while significant hair loss from baseline was demonstrated in those treated with placebo." (section 14.1 Studies in Men).
12 months	1 mg once daily	A 107-hair difference from placebo in a 1-inch circle. "At 12 months there was a 107-hair difference from placebo (p<0.001, PROPECIA [n=679] vs placebo [n=672]) within a 1-inch diameter circle (5.1 cm2)." (section 14.1 Studies in Men).
2 years	1 mg once daily	The peak: maximum hair count improvement is reached here. "Hair count was maintained in those men taking PROPECIA for up to 2 years, resulting in a 138-hair difference between treatment groups (p<0.001, PROPECIA [n=433] vs placebo [n=47]) within the same area. In men treated with PROPECIA, the maximum improvement in hair count compared to baseline was achieved during the first 2 years." (section 14.1 Studies in Men).
5 years	1 mg once daily	The gap keeps widening — because the placebo group keeps falling. "Although the initial improvement was followed by a slow decline, hair count was maintained above baseline throughout the 5 years of the studies. Furthermore, because the decline in the placebo group was more rapid, the difference between treatment groups also continued to increase throughout the studies, resulting in a 277-hair difference (p<0.001, PROPECIA [n=219] vs placebo [n=15]) at 5 years." (section 14.1 Studies in Men). This is the furthest point the label makes any claim about.
Within 12 months of stopping	None — treatment discontinued	"Withdrawal of treatment leads to reversal of effect within 12 months." (section 2 Dosage and Administration). The withdrawal sub-study in section 14.1 is more specific: "A change of treatment from PROPECIA to placebo (n=48) at the end of the initial 12 months resulted in reversal of the increase in hair count 12 months later, at 24 months."

Ceiling. The label states no maximum dose, because it states only one dose. Section 2 names 1 mg once daily and offers no titration and no second strength. Section 10 reports what was tolerated rather than what is permitted: "In clinical studies, single doses of finasteride up to 400 mg and multiple doses of finasteride up to 80 mg/day for three months did not result in adverse reactions." That is a safety observation in healthy volunteers, not an authorisation, and no finasteride label recommends any dose above 1 mg for hair.

How it is supplied

Presentation	Total strength	Concentration	Delivers
Tan, octagonal, film-coated convex tablet — bottle of 30 (with desiccant)	1 mg	Not applicable — a solid oral dose form has no concentration	One tablet daily; "stylized P" logo on one side and PROPECIA on the other
Tan, octagonal, film-coated convex tablet — PROPAK bottle of 90 (with desiccant)	1 mg	Not applicable — a solid oral dose form has no concentration	One tablet daily; the same tablet as the 30-count bottle, three months at a time

Administration, as the label words it

—HANDLING — the most important instruction on this label. "Women should not handle crushed or broken PROPECIA tablets when they are pregnant or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male fetus. PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed." (section 5.1 Exposure of Women — Risk to Male Fetus).
—If a woman who is pregnant or may potentially be pregnant comes in contact with crushed or broken PROPECIA tablets, the contact area should be washed immediately with soap and water.
—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. Withdrawal of treatment leads to reversal of effect within 12 months.
—Physicians should instruct their patients to promptly report any changes in their breasts such as lumps, pain or nipple discharge.
—Any confirmed increase from the lowest PSA value while on PROPECIA may signal the presence of prostate cancer and should be evaluated, even if PSA levels are still within the normal range for men not taking a 5α-reductase inhibitor.

Storage

Tablets: Store at room temperature, 15–30 °C (59–86 °F). Keep container closed and protect from moisture — both package sizes ship with a desiccant.; Until the expiration date on the bottle
Handling by anyone who is or may become pregnant: Intact tablets only. The coating is the stated barrier and it fails once the tablet is broken or crushed.; No exposure to a broken or crushed tablet at any time

Children and adolescents

PROPECIA is not indicated for use in pediatric patients. Safety and effectiveness in pediatric patients have not been established.

This statement belongs to Propecia tablets. It is not a statement about finasteride, and another brand of the same molecule may say the opposite.

The same molecule under other brand names

Everything below is finasteride. None of it is Propecia, and a dose from one column carried into another is not a smaller or larger version of the same instruction — it is a different product’s schedule.

Brand	Form	Approved for	Ladder	Maximum
Proscar	Oral tablet, 5 mg, once a day — blue, modified apple-shaped, coded MSD 72	Symptomatic benign prostatic hyperplasia in men with an enlarged prostate: improve symptoms, reduce the risk of acute urinary retention, reduce the risk of needing surgery; and in combination with doxazosin to reduce the risk of symptomatic progression	5 mg once a day — one dose, no titration	No maximum stated; the label names a single 5 mg dose, and adds that PROSCAR is not approved for the prevention of prostate cancer

Switching between products

The coating is the safeguard, and only while the tablet is intact

PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed.

Propecia

Pregnancy is a contraindication, and the reason is specific

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.

Propecia

The same sentence appears on the 5 mg label about its own tablet

PROSCAR tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed.

Proscar — the 5 mg tablet people quarter

What this page does not tell you

Price — list, cash or copay: No price appears anywhere on this page, and no price is emitted in its structured data. Finasteride is sold as two brands and dozens of generics at both strengths, at rates that differ by package size, pharmacy and discount programme, and a figure quoted here would be stale before it was read. Our finasteride cost tool works from a dated national acquisition-cost snapshot with its as-of date attached, which is the only form in which we will state one — this page links to it rather than printing a number.
Whether it is safe to quarter a 5 mg tablet to make a 1 mg dose: Neither finasteride label answers the question and this page will not answer it for them. The word "split" does not occur in any finasteride label read for our cost module (confirmed across eight SPLs), both tablets are declared unscored, and FDA’s position is that approval to split would appear in the HOW SUPPLIED section and be marked by a score on the tablet — neither of which is present. What the labels do state is that the coating is what prevents contact with the active ingredient, and only while the tablet has not been broken or crushed. Stating a prohibition would invent one; stating that it is fine would ignore the only handling sentence the labels give.
A topical finasteride dose: There is no FDA-approved topical finasteride and therefore no labelled dose, concentration or application schedule to quote. One TOPICAL-routed finasteride record exists in FDA’s listing databases under marketing category "OTC Monograph Drug", which is a self-declared registration FDA does not review before publication rather than an approval — finasteride is a prescription drug and appears in no OTC monograph. Everything circulating as a topical finasteride protocol is compounded, and nothing on file supports a number.
How much hair an individual should expect: The label reports group results from named trials at fixed timepoints — a hair-count difference from placebo inside a 1-inch circle, and the proportion of men rated as improved by investigators and by a blinded photographic panel. Those are averages in men aged 18 to 41 with mild to moderate loss who were all using a specified medicated shampoo for the first two years, and they are not a forecast for one person. The figures and the timepoints they belong to are in the ladder above and in our hair-loss timeline tool.

Frequently asked questions

What is the difference between Propecia and Proscar?: Strength, indication and population. Propecia is finasteride 1 mg once daily, approved for male pattern hair loss in men only, with evidence from men aged 18 to 41. Proscar is finasteride 5 mg once a day, approved for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, with evidence from men aged 45 to 78. The Propecia label refers to the 5 mg dose in its own words as "5 times the dose of PROPECIA".
Can a 5 mg finasteride tablet be cut into quarters?: No label says. The word "split" appears in no finasteride label, both tablets are declared in their structured product data as one piece — unscored — and FDA states that a tablet approved for splitting says so in its HOW SUPPLIED section and carries a score mark. Neither applies here. What the labels do say is that the coating is what prevents contact with the active ingredient, "provided that the tablets have not been broken or crushed", so breaking one removes the barrier the pregnancy warning relies on.
Why can a pregnant woman not touch the tablet?: She can touch an intact one — that is exactly what the label says. "PROPECIA tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed." The risk is a broken or crushed tablet: finasteride may cause abnormalities of the external genitalia of a male fetus, and pregnancy is a contraindication. If contact with a broken tablet does occur, the label directs washing the area immediately with soap and water.
How long does Propecia take to work?: The label's own expectation is three months at minimum: "In general, daily use for three months or more is necessary before benefit is observed." The trial timepoints run further out — a 107-hair difference from placebo within a 1-inch circle at 12 months, 138 hairs at 2 years and 277 hairs at 5 years, with the label noting that maximum improvement in hair count compared to baseline was achieved during the first 2 years and the gap kept widening mainly because the placebo group kept declining.
What happens if you stop taking it?: The label states it in one sentence: "Withdrawal of treatment leads to reversal of effect within 12 months." Section 14.1 gives the study it came from: "A change of treatment from PROPECIA to placebo (n=48) at the end of the initial 12 months resulted in reversal of the increase in hair count 12 months later, at 24 months." Continued use is what the label recommends to sustain benefit, with periodic re-evaluation.
Does Propecia affect a PSA test?: Yes, and by less than people expect at this dose. In men aged 18 to 41 the mean serum PSA fell from 0.7 ng/mL at baseline to 0.5 ng/mL at month 12. The familiar instruction to double a PSA result comes from the 5 mg product, where levels are decreased by approximately 50% in older men with benign prostatic hyperplasia. The label’s standing advice applies at either dose: any confirmed increase from the lowest PSA value while on finasteride should be evaluated, even within the normal range.
How common are sexual side effects on 1 mg?: In year 1 of the Propecia trials, drug-related reactions at 1% or more were decreased libido 1.8% versus 1.3% on placebo, erectile dysfunction 1.3% versus 0.7% and ejaculation disorder 1.2% versus 0.7%, with the incidence of each falling to 0.3% or less by the fifth year. The much-quoted 8.1% impotence figure is from PLESS, a four-year study of the 5 mg tablet in men aged 45 to 78, where the placebo rate was 3.7%.
Is Propecia approved for women?: No, and the label refuses it three times over. Section 1 states it is indicated "in MEN ONLY" and that "PROPECIA is not indicated for use in women". Section 4 makes pregnancy a contraindication. And section 14.2 reports the study: "In a study involving 137 postmenopausal women with androgenetic alopecia who were treated with PROPECIA (n=67) or placebo (n=70) for 12 months, effectiveness could not be demonstrated." It is also not indicated in pediatric patients, and clinical efficacy studies did not include anyone aged 65 or over.

Sources

Next steps

Compare online hair-loss providersWho prescribes branded finasteride, who prescribes generic, who pushes compounded topicals, and what each one asks for first.Put the label’s timeline on your calendarEnter a start date and see when each labelled milestone falls, with the sentence it came from attached.

Other brands

Educational reference, not medical advice. Finasteride is a prescription-only medicine, contraindicated in pregnancy, and not indicated for women or children. This page reports what two FDA labels state; it does not recommend a dose or a product.