This sheet is about exposure to finasteride in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare providers.

What is finasteride?

Finasteride is a medication that has been used to treat male pattern hair loss and benign prostatic hyperplasia (enlarged prostate). Oral finasteride (a pill taken by mouth) has been approved by the U.S. Food and Drug Administration (FDA) for use in males. Finasteride is not approved for use in females but has been used “off-label” in females to treat hair loss and hirsutism (extra hair growth on areas of the body such as the face, chest, and back). Some brand names for finasteride are Propecia® and Proscar®.

Topical finasteride (used on the skin) has not been approved by the U.S. FDA, but has been used to treat male and female pattern hair loss. This fact sheet will focus on the use of oral finasteride. Finasteride, in any form, is not recommended for use by someone who is pregnant.

I am taking finasteride, but I would like to stop taking it before becoming pregnant. How long does the drug stay in my body?

People eliminate medication at different rates. In healthy adults, it takes up to 2 days, on average, for most of the finasteride to be gone from the body.

I take finasteride. Can it make it harder for me to get pregnant?

It is not known if finasteride can make it harder to get pregnant. Some people taking finasteride have reported reduced desire to have sex (low libido).

I just found out I am pregnant. Should I stop taking finasteride?

Finasteride is not recommended for use during pregnancy. If you are taking finasteride and find out that you are pregnant, contact your healthcare provider to talk about your exposure.

Does taking finasteride increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done to see if taking finasteride could increase the chance of a miscarriage.

Does taking finasteride increase the chance of birth defects?

Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Studies have not been done in humans to see if finasteride increases the chance for birth defects above the background risk.

Animal studies have suggested that exposure to large doses of finasteride when the fetal sex organs are developing (8 to 12 weeks of pregnancy) could increase the chance for some birth defects of the sex organs in a male fetus. The animal studies have reported hypospadias (when the opening of the penis is on the underside of the penis instead of at the tip), a shorter distance from the anus to the genitals (anogenital distance), and lower weight of the prostate and seminal vesicles (glands that help make semen).

If I touch or handle finasteride tablets during pregnancy, is there an increased chance for birth defects?

People who are pregnant are told not to handle finasteride tablets that are crushed or broken as a precaution. The coating on uncrushed or unbroken tablets should prevent contact with finasteride during normal handling. If you touch or handle crushed or broken finasteride tablets, wash your hands. It is unlikely that enough of the medication would get through the skin to be a problem.

People who are required to work with finasteride as part of their job should wear gloves, clean surface areas where pills are handled, and wash their hands. Workers should discuss proper handling and storage with their occupational safety officers. For more information about workplace exposures, see the MotherToBaby fact sheet here: https://mothertobaby.org/fact-sheets/reproductive-hazards-workplace/.

Does taking finasteride in pregnancy increase the chance of other pregnancy-related problems?

Studies have not been done in humans to see if finasteride increases the chance for pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth).

Experimental animal studies suggest that finasteride exposure in pregnancy might increase the chance of preterm delivery and might affect the ability of the baby’s testicles to move down into the proper position in the scrotum (the bag of skin hanging below the penis). This process is called testicular descent and usually happens on its own in most males soon after their birth.

Does taking finasteride in pregnancy affect future behavior or learning for the child?

Studies have not been done in humans to see if finasteride can cause behavior or learning issues for the child. An animal study reported use of finasteride in pregnancy might affect memory in some exposed offspring.

Breastfeeding while taking finasteride:

Finasteride use while breastfeeding has not been studied. No information is available on its transfer into human milk. Be sure to talk to your healthcare provider about all your breastfeeding questions.

If a male is taking finasteride, should they stop taking finasteride before trying to get a partner pregnant?

Males taking finasteride should discuss the benefits of taking the medication and possible harmful effects from not taking it with their healthcare provider before deciding to stop treatment.

If a male takes finasteride, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects in a partner’s pregnancy?

Problems with sexual function have been reported in males taking finasteride. Some small differences have been seen in the semen of males who take finasteride, such as low sperm counts. Sperm levels improved when the medication was stopped.

A study in rats did not show an increased chance for birth defects in the offspring of female rats who had mated with male rats given finasteride.

There has been concerns about an increased chance of birth defects involving the sex organs of male babies if a male and female had unprotected sex during the critical time in pregnancy when the sex organs are developing (8 to 12 weeks of pregnancy). However, the amount of finasteride found in semen is small. If fetal exposure to the drug is only through semen with vaginal sex, the amount of finasteride in semen is not expected to be enough to cause a problem for the developing baby. There are case reports of pregnancies with documented paternal exposure to finasteride either before or during pregnancy that resulted in the birth of full-term infants without reported birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

Selected References:

• Ahn KH, et al. 2015. Pregnancy outcomes with paternal exposure to finasteride, a synthetic 5-alpha-reductase inhibitor: a case-series. J Clin Toxicol 5:2
• AlSaad D, et al. 2018. Finasteride use during pregnancy and early neonatal outcome: a case report. Int J Clin Pharm 40(4): 803-805. [PubMed: 29855987]
• Amory JK, et al. 2007. The effect of 5- alpha-reductase inhibition with dutasteride and finasteride on semen parameters and serum hormones in healthy men. J Clin Endocrinol Metab 92:1659-1665. [PubMed: 17299062]
• Anderson CA, Clark RL. 1990. External genitalia of the rat: normal development and the histogenesis of 5 alpha-reductase inhibitor-induced abnormalities. Teratology;42:483-496. [PubMed: 2177574]
• Bowman CJ, et al. 2003. Effects of in utero exposure to finasteride on androgen-dependent reproductive development in the male rat. Toxicol Sci; 74:393-406. [PubMed: 12773767]
• Carlin JR, et al. 1992. Disposition and pharmacokinetics of (14C) finasteride after oral administration in humans. Drug Metab Dispos Biol Fate Chem; 20:148-55. [PubMed: 1352203]
• Cather JC, et al. 1999. Finasteride – An update and review. Cutis 64:167-172. [PubMed: 10500917]
• Ciotta L, et al. 1995. Clinical and endocrine effects of finasteride, a 5(alpha)-reductase inhibitor, in women with idiopathic hirsutism. Fertil Steril 64:299-306. [PubMed: 7615107]
• Clark RL, Anderson CA, Prahalada S et al: Critical developmental periods for effects on male rat genitalia induced by finasteride, a 5(alpha)-reductase inhibitor. Toxicol Appl Pharmacol 119:34-40. [PubMed: 8385814]
• Clark RL, et al. 1990. External genital abnormalities in male rats exposed in utero to finasteride, a 5-alpha reductase inhibitor. Teratology; 42:91-100. [PubMed: 2168096]
• Falsetti L, et al. 1997. Treatment of hirsutism by finasteride and flutamide in women with polycystic ovary syndrome. Gynecol Endocrinol 11:251-157. [PubMed: 9272421]
• Husmann DA, McPhaul MJ. 1991. Time-specific androgen blockade with flutamide inhibits testicular descent in the rat. Endocrinology; 129:1409-1416. [PubMed: 1678699]
• Gupta AK & Talukder M. 2022. Topical finasteride for male and female pattern hair loss: Is it a safe and effective alternative?. Journal of cosmetic dermatology, 21(5), 1841–1848. [PubMed: 35238144]
• Khera M, et al. 2020. Penile vascular abnormalities in young men with persistent side effects after finasteride use for the treatment of androgenic alopecia. Transl Androl URol 9(3): 1201-1209. [PMC free article: PMC7354335] [PubMed: 32676403]
• Kohler C, et al. 2007. Effect of finasteride 5mg (Proscar) on acne and alopecia in female patients with normal serum levels of free testosterone. Gynecol Endocrinol; 23:142-145. [PubMed: 17454167]
• Kurzrock EA, et al. 2000. Urethral development in the fetal rabbit and induction of hypospadias: a model for human development. J Urol 164(5):1786-1792. [PubMed: 11025770]
• Laborde, E. and R. E. Brannigan. 2010. Effect of 1-mg dose of finasteride on spermatogenesis and pregnancy. J Androl; 31(2): e1-2. [PubMed: 19834128]
• Lumachi F, Rondinone R. 2003. Use of cyproterone acetate, finasteride, and spironolactone to treat idiopathic hirsutism. Fertil Steril 79:942-946. [PubMed: 12749435]
• Martinez AG, et al. 2011. Effects of in utero exposure to D-004, a lipid extract from Roystonea regia fruits, in the male rat: a comparison with finasteride. J Med Food. Dec;14(12):1663-9. [PubMed: 21861713]
• Overstreet JW, et al. 1999. Chronic treatment with finasteride daily does not affect spermatogenesis or semen production in young men. J Urol 162:1295-1300. [PubMed: 10492183]
• Paris JJ, et al. 2011. Inhibition of 5 alpha reductase activity in late pregnancy decreases gestational length and fecundity and impairs object memory and central progestogen milieu of juvenile rat offspring. J Neuroendocrinol; 23(11): 1079-90. [PMC free article: PMC3196810] [PubMed: 21914008]
• Prahalada S, et al. 1997. Effects of finasteride, a type 2 5-alpha reductase inhibitor, on fetal development in the Rhesus monkey (Macaca mulatta). Teratology; 55:119-31. [PubMed: 9143092]
• Propecia prescribing information. 2020. Accessible from https://dailymed​.nlm​.nih.gov/dailymed/drugInfo​.cfm?setid=4e07adb4-7807-47d3-b9a9-2332a3047410#S12.3
• Ricci G, et al. 2012. Finasteride and fertility: case report and review of the literature. J Drugs Dermatol; 11(12):1511-3. [PubMed: 23377525]
• Rittmaster, RS, 1994. Drug Therapy: Finasteride. New Engl J Med 330:120-125. [PubMed: 7505051]
• Salvarci A, Istanbulluoglu O. 2013. Secondary infertility due to use of low-dose finasteride. Int Urol Nephrol; 45(1):83-5. [PubMed: 23070721]
• Samplaski MK, et al. 2013. Finasteride use in the male infertility population: effects on semen and hormone parameters. Fertility and Sterility; 100:1528-1529. [PubMed: 24012200]
• Spencer JR, et al. 1991. Effects of flutamide and finasteride on rat testicular descent. Endocrinology; 129:741-748. [PubMed: 1677329]
• Teichert M, et al. 2017. Contraindicated use of 5-alpha-reductase inhibitors in women. Br J Clin Pharmacol. 83(2): 429-431 [PMC free article: PMC5237684] [PubMed: 27567019]
• Wise LD, et al. 1991. Reversible decreases of fertility in male Sprague-Dawley rats treated orally with finasteride, a 5-alpha-reductase inhibitor. Reprod Toxicol 5:353-362. [PubMed: 1666857]