The prescribing information for Propecia (finasteride 1 mg) says Propecia is not indicated for use in women and is not indicated for use in pediatric patients. Its Patient Information says Propecia is not for use by women and children. The label also says finasteride use is contraindicated in women when they are or may potentially be pregnant.
What the label says about women, pregnancy and children
The Propecia label says finasteride may cause abnormalities of the external genitalia of a male fetus of a pregnant woman who receives finasteride. It also says that in animal studies, finasteride caused abnormal development of external genitalia in male fetuses.
The Patient Information says it in plain words. If a woman who is pregnant with a male baby swallows or comes in contact with the medicine in Propecia, the male baby may be born with sex organs that are not normal.
For children, the label says safety and effectiveness in pediatric patients have not been established.
How exposure can happen, and what the label says about handling
The label says women could be exposed to finasteride through contact with crushed or broken Propecia tablets or semen from a male partner taking Propecia. On handling, it says:
- 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.
- The tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed.
- If a pregnant woman comes in contact with crushed or broken tablets, the contact area should be washed immediately with soap and water.
The Patient Information also says that females who are pregnant or who may become pregnant should not come in contact with broken or crushed Propecia tablets.
The semen figures in the label
Because the label names semen as a route of exposure, it also reports a measurement and a calculation. The measurement is in men taking finasteride 1 mg/day.
| Question | What the label says |
|---|---|
| What was measured? | Semen levels in 35 men taking finasteride 1 mg/day for 6 weeks. |
| How many samples were undetectable? | In 60% (21 of 35) of the samples, finasteride levels were undetectable (<0.2 ng/mL). |
| What were the mean and highest levels? | The mean finasteride level was 0.26 ng/mL and the highest level measured was 1.52 ng/mL. |
| What did the label estimate? | Using the highest semen level measured and assuming 100% absorption from a 5-mL ejaculate per day, human exposure through vaginal absorption would be up to 7.6 ng per day, which is 650-fold less than the dose of finasteride (5 µg) that had no effect on circulating DHT levels in men. |
What the FDA says
An FDA alert about compounded topical finasteride products states that approved finasteride products are contraindicated in pregnancy because of the potential to cause abnormalities of a male fetus in a pregnant woman. The same page states that compounded topical finasteride products pose a greater potential risk for inadvertent exposure to others, specifically females, through transfer of applied product.
What this does not tell you
The semen figures are one measurement in 35 men and one estimate that rests on the label's stated assumptions, including 100% absorption. The comparison in the label is to circulating DHT levels in men. This article does not say whether any amount of exposure is without effect in pregnancy. It reports the label's wording and nothing more.
A woman who is or may be pregnant and has a question about exposure can ask a licensed health care provider. Whether finasteride 1 mg is appropriate for a man is a decision for a licensed provider after review.