Prescription only
Finasteride
Sold as Propecia (1 mg), Proscar (5 mg).
What the label states
PROPECIA, for hair: “The recommended dose of PROPECIA is one tablet (1 mg) taken once daily.” PROSCAR, for benign prostatic hyperplasia: “The recommended dose of PROSCAR is one tablet (5 mg) taken once a day.” Both labels add that the tablet may be administered with or without meals.
Quoted from the approved product label. Clinics commonly prescribe differently — more frequent, smaller injections of the same weekly total are routine — and where this site describes that, it is named as practice rather than as labelling.
- Route
- Oral, once daily, with or without meals
- Vehicle
- None — a film-coated tablet. The coating is not cosmetic: it is the barrier the label relies on to prevent skin contact with the active ingredient.
- Usual barrel
- None — this compound is not drawn into a syringe
- Strengths covered
- No strength page yet
Why there is no syringe
There is no syringe, and the reason is worth stating rather than leaving blank, because the one finasteride preparation people do try to measure is the one with no label at all. Both approved products are film-coated oral tablets — 1 mg PROPECIA and 5 mg PROSCAR — swallowed whole. Topical finasteride is compounded, has no FDA-approved product behind it, and is measured in millilitres of a solution whose strength is whatever the prescription specified; /tools/topical-finasteride-calculator does that arithmetic and refuses to propose a strength. The handling warning is the reason not to improvise with either form: the label’s protection against fetal exposure is the tablet coating itself, so a split tablet, a crushed tablet or a liquid is outside what the label describes.
Administration
- 1
Know which of the two labelled products you have
They are not the same drug at a different dose in any practical sense. PROPECIA is 1 mg and is “indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY”, with efficacy in bitemporal recession not established. PROSCAR is 5 mg and is indicated for symptomatic benign prostatic hyperplasia. Neither label authorises using the other product’s tablet as a substitute, and PROSCAR’s label adds a limitation of use: “PROSCAR is not approved for the prevention of prostate cancer.”
- 2
Swallow the tablet whole — do not split or crush it
This is the single most important handling instruction on the label, and it is not about the drug’s stability. “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.” Splitting a 5 mg tablet to approximate 1 mg breaks that barrier, and the label’s own pregnancy warning then applies to everyone who touches it.
- 3
Keep the tablets away from anyone who is or may become pregnant
PROPECIA’s section 5.1 is headed “Exposure of Women — Risk to Male Fetus” and states: “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.” Section 8.1 adds the instruction if it happens anyway: “If a pregnant woman comes in contact with crushed or broken PROPECIA tablets, the contact area should be washed immediately with soap and water.” PROSCAR carries the same warning in the same terms.
- 4
Take it at the same time each day, with or without food
Both labels state the tablet may be administered with or without meals, and both specify once daily. There is no loading dose and no titration on either product.
- 5
Give it three months before judging it, and expect it to be conditional on continuing
PROPECIA’s dosage section states: “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.” That last sentence is the label’s own, and it is the part most often left out of marketing copy.
- 6
Tell anyone testing your PSA that you take it
Finasteride lowers PSA. The PROPECIA label carries a dedicated warning on the effect of finasteride on prostate-specific antigen, and the parallel dutasteride label quantifies the same problem: a roughly 50% reduction, so the measured value must be interpreted against a new on-treatment baseline rather than the untreated reference range.
Storage
- —PROPECIA: “Store at room temperature, 15-30°C (59-86°F). Keep container closed and protect from moisture.”
- —PROSCAR: “Store at room temperatures below 30°C (86°F). Protect from light and keep container tightly closed.”
- —Keep the container closed and out of reach of children and of anyone who is or may become pregnant. The label’s handling protection is the intact coating, so a bottle of loose or broken tablets is a different risk from a sealed one.
- —A compounded topical finasteride solution is not covered by either of these. Its beyond-use date is set by the pharmacy that made it and is frequently shorter than the bottle lasts.
Monitoring
| Marker | When | Why |
|---|---|---|
| PSA | Baseline before starting, then re-baselined on treatment | Finasteride suppresses PSA, so an on-treatment value read against the untreated reference range understates the true figure. The 5 mg label carries a dedicated warning on this and the parallel dutasteride label states the magnitude — approximately 50% within 3 to 6 months — and instructs clinicians to establish a new baseline and investigate any confirmed rise from it. |
| Response to treatment | At three months at the earliest, then periodically | The PROPECIA label states that three months or more of daily use is generally needed before benefit is observed and that benefit “should be re-evaluated periodically”. Judging it earlier than three months is judging it before the label says it can be judged. |
| Household exposure | At every prescription where a household member may become pregnant | The contraindication is categorical: “Finasteride use is contraindicated in women when they are or may potentially be pregnant.” The practical control is that tablets stay intact and stay out of reach. |
| Sexual function and mood | Symptom-driven | The label’s postmarketing experience section records reports in these areas. They are reasons to speak to a prescriber rather than figures to track, and this page does not put an incidence number on them because the ones in circulation come from sources of very mixed quality. |
Frequently asked questions
- What dose does the FDA label actually state for hair loss?
- One tablet of 1 mg once daily. PROPECIA’s dosage section reads: “The recommended dose of PROPECIA is one tablet (1 mg) taken once daily,” and its indication is “the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY.” The 5 mg tablet is PROSCAR and is approved for benign prostatic hyperplasia, not hair. Both are labelled products; they are not interchangeable, and the label gives no instruction for converting one into the other.
- Is topical finasteride FDA-approved?
- No. There is no approved topical finasteride application in Drugs@FDA; every approved finasteride product is an oral tablet. One caveat worth knowing about, because it looks like a counter-example: the openFDA listing database now carries a single TOPICAL finasteride record — “JOHNSON FOAM PRO”, finasteride 0.25% with minoxidil 5%, NDC 84539-002, registered by Johnson Biopharmaceutical Inc. under marketing category “OTC Monograph Drug”. Finasteride is a prescription drug and is in no OTC monograph, so that category cannot be right, and a listing of this kind is self-declared rather than FDA-reviewed. Its SPL contains no Drug Facts sections at all, only product data and text evidently scanned off a carton, misspellings included. A listing is not an approval.
- Why does the label warn about handling the tablets at all?
- Because finasteride blocks the conversion of testosterone to dihydrotestosterone, which a male fetus needs for normal genital development, and it can be absorbed through skin from uncoated drug. Both labels are explicit that the protection is the coating: “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.” So an intact tablet is safe to hand someone; a split or crushed one is not, and neither is a compounded liquid, which has no coating at all. If contact occurs the label says “the contact area should be washed immediately with soap and water.”
- Can I cut a 5 mg Proscar tablet into quarters to get about 1 mg?
- This page will not describe how to do that, and the label is the reason rather than pedantry. Cutting the tablet destroys the coating the label names as the barrier against skin contact with finasteride, which converts a warning about crushed tablets from hypothetical into the state of your pill organiser. Beyond that, a quarter of a 5 mg tablet is 1.25 mg and the split is not uniform, so it is neither the 1 mg dose nor a controlled one. The 1 mg product exists and is approved for exactly this indication.
- How long before it works, and what happens if I stop?
- The label answers both in one sentence: “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.” Three months is the earliest the label expects a judgement, and the effect is conditional on continuing — it is a maintenance drug, not a course.
- Does this page tell me whether to take finasteride?
- No. It quotes two labels and names which product is approved for which condition. Whether a 5α-reductase inhibitor is appropriate, at which of the two approved doses, and against which risks, is a decision that needs a prescriber — as is the question of whether a compounded topical, which has no label at all, is a reasonable thing to be handed.
Sources
- [1]FDA label — PROPECIA (finasteride) tablets, 1 mg, Organon LLC (DailyMed SPL 6f904709-65aa-44ce-b144-b4c8a0416e36; Drugs@FDA NDA 020788, initial US approval 1992). Source of the 1 mg once-daily dose, the MEN ONLY indication, the pregnancy contraindication, the section 5.1 coating statement and the three-month/12-month statements
- [2]FDA label — PROSCAR (finasteride) tablets, 5 mg, Organon LLC (DailyMed SPL 6f988153-fc74-4ca4-b29a-111f750c4a4b; Drugs@FDA NDA 020180). The other approved finasteride strength — benign prostatic hyperplasia, not hair loss — carrying the same pregnancy contraindication and handling warning, and the limitation of use “PROSCAR is not approved for the prevention of prostate cancer”
- [3]openFDA drug label and NDC directory — the finasteride listing query behind the topical caveat above. 74 label records, 73 routed ORAL and 1 routed TOPICAL, the topical being NDC 84539-002 “JOHNSON FOAM PRO” under marketing category OTC MONOGRAPH DRUG. Queried against the 2026-09-18 data refresh
- [4]Drugs@FDA: FDA-Approved Drugs — the approval record. Used to confirm NDA 020788 (PROPECIA) and NDA 020180 (PROSCAR), and to confirm that no approved topical finasteride application exists
Related
Educational reference, not medical advice. Dose, route and whether this compound is appropriate at all are decisions for your clinician.