The short answer
- Yes, finasteride can be split. It is immediate-release; quartering 5 mg tablets to about 1.25 mg is a common, cheaper way to treat hair loss.
- Handling: whole tablets are coated and safe to touch. Broken pieces and dust must not be handled by anyone pregnant or trying to conceive. Split them yourself, over a surface you wipe afterwards.
- Dose: 1 mg daily for hair loss; 5 mg daily for an enlarged prostate. Don’t change your prostate dose without your doctor.
Finasteride strengths and uses
| Strength |
Brand examples |
Use |
| 1 mg |
Propecia, generic |
Male pattern hair loss |
| 5 mg |
Proscar, generic |
Benign prostatic hyperplasia (enlarged prostate) |
| Topical (some countries) |
Finasteride spray |
Hair loss, lower blood levels |
Finasteride blocks the enzyme 5-alpha reductase, which converts testosterone into dihydrotestosterone (DHT). Lower DHT slows hair loss and shrinks the prostate. Studies show the effect on scalp DHT levels is similar from 0.2 mg to 1 mg a day, which is why a quarter of a 5 mg tablet (about 1.25 mg) gives a comparable result to 1 mg for hair loss.
How to split finasteride safely
- Use a pharmacy tablet cutter; 5 mg tablets are small and quarters won’t be perfectly equal. Daily dosing evens this out.
- Split over a paper towel or a surface you can wipe, and wash your hands afterwards.
- Keep split pieces in a closed container, away from children, and don’t let a pregnant partner handle them.
- Splitting a few days’ supply at a time is fine; keep pieces dry.
- Don’t crush tablets for swallowing; finasteride tablets are small and swallowable.
Why the pregnancy warning? Finasteride can be absorbed through the skin from broken tablets. In a pregnant person carrying a male baby, it can interfere with normal development of the genitals. Intact coated tablets are not a risk to touch. Semen contains only tiny amounts, which manufacturers consider no risk to a pregnant partner.
Side effects to know about
Most men have no side effects. Possible effects include lower libido, erection or ejaculation problems, breast tenderness or enlargement, and, rarely, depression or suicidal thoughts. In 2024 the UK medicines regulator (MHRA) added a patient alert card to finasteride packs warning about psychiatric and sexual side effects, which in some men have persisted after stopping, and it strengthened these warnings again in May 2026. Report any mood changes promptly. Finasteride also lowers PSA blood test results by about half, so tell your doctor you take it before prostate testing.
Other splitting questions are covered in our guide to taking medicines correctly.
Frequently asked questions
Can finasteride for the prostate be cut in half?
The tablet can be split, but for an enlarged prostate the licensed dose is 5 mg daily. Halving it would mean a lower dose than prescribed; only do this if your doctor has recommended it.
Can I take 5 mg every few days instead of splitting?
That approach gives less steady levels and isn’t how the drug was studied. Daily dosing of a split tablet is more consistent.
Can dutasteride capsules be opened or cut?
No. Dutasteride (Avodart) soft capsules contain liquid that irritates the mouth and can be absorbed through skin; they must be swallowed whole and not handled if leaking by anyone pregnant.
Sources and further reading
CanforaMedicine Guide
