Can I take finasteride while pregnant or breastfeeding?

A plain-words look at what the NHS, the US drug label and LactMed say about finasteride.

In short

Pregnancy: Semen contains only very small amounts of finasteride. If your partner takes finasteride while you're pregnant, it's very unlikely to harm you or your baby.

Breastfeeding: There isn't a simple UK NHS summary for this medicine. Ask your doctor or pharmacist.

Your doctor, midwife or pharmacist can help you decide.

What this means for you

Pregnancy

Talk to your doctor or pharmacist

This page is educational, not advice for your own situation. Talk to your doctor, midwife or pharmacist before you start, stop or change any medicine in pregnancy or while breastfeeding.

The details: what each source says

Finasteride in pregnancy

The NHS says

Semen contains only very small amounts of finasteride. If your partner takes finasteride while you're pregnant, it's very unlikely to harm you or your baby.

The makers of finasteride still advise using a condom during sex, but the real risk is unlikely to be significant, and most experts agree a condom is not necessary for this reason.

In our words, from the NHS page Finasteride (nhs.uk). Contains public sector information licensed under the Open Government Licence v3.0 (OGL v3.0). The NHS does not endorse this site.

What these words mean

contraindicated
there is a reason not to use this medicine, because it may be harmful
embryo-fetal
about the embryo and fetus (a baby's early stages of growing in the womb)

Definitions adapted from the NCI Dictionary of Cancer Terms (National Cancer Institute).

The US drug label says

8.1 Pregnancy Risk Summary Finasteride is contraindicated in pregnant females and not indicated for use in females. Based on animal studies and the mechanism of action, finasteride may cause abnormal development of external genitalia in a male fetus if administered to a pregnant female [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.1) ]. In an embryo-fetal development study in rats, there was a dose-dependent increase in hypospadias that occurred in 3.6 to 100% of male offspring of pregnant rats administered oral finasteride during the period of major organogenesis at doses approximately 0.1 to 86 times the maximum recommended human dose (MRHD) of 5 mg/day (based on AUC at animal doses of 0.1 to 100 mg/kg/day). Decreased prostatic and seminal vesicular weights, delayed preputial separation and transient nipple development were also observed in male offspring at oral maternal doses approximately 0.03 times the MRHD (based on AUC at animal dose of 0.03 mg/kg/day), along with decreased anogenital distance in male offspring at oral maternal doses approximately 0.003 times the MRHD (based on AUC at animal dose of 0.003 mg/kg/day).

Prescribing label, section “8.1 Pregnancy” (opening excerpt): Finasteride (oral), Bryant Ranch Prepack. Read the full section on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.

Finasteride while breastfeeding

The US prescribing label says

8.2 Lactation Risk Summary Finasteride is not indicated for use in females.

Prescribing label, section “8.2 Lactation”: Finasteride (oral), Bryant Ranch Prepack. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.

Other names

UK brand names (per the NHS): Proscar, Propecia.

Sources

  1. NHS, Finasteride (nhs.uk), page last reviewed 2 August 2023. Paraphrased. Contains public sector information licensed under the Open Government Licence v3.0.
  2. US drug label: Finasteride (oral), Bryant Ranch Prepack, human prescription drug, label effective 9 September 2026, set ID c9a3cb34-9a8e-4538-ab90-32e08d8acc3a. DailyMed (National Library of Medicine). Public domain; quoted verbatim.

Sources checked 26 September 2026. How we source and check every page.

Educational summary of named sources, not medical advice.