Is it safe for a male to conceive while taking finasteride (5-alpha-reductase inhibitor) 5 milligrams?

From the Guidelines

Finasteride 5 mg is not recommended for men who are actively trying to conceive with their partner. This medication, commonly used to treat enlarged prostate and male pattern baldness, works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT). While there is limited data on the effects of finasteride on paternal fertility and fetal development, the available evidence suggests that it is best to exercise caution. According to the 2020 American College of Rheumatology guideline for the management of reproductive health in rheumatic and musculoskeletal diseases 1, there are no reports of post-conception teratogenesis attributable to medications taken by a man with RMD, but this does not necessarily apply to finasteride.

Key Considerations

• The medication can affect sperm parameters, including count, motility, and morphology, potentially reducing fertility.
• If a pregnant woman handles crushed or broken finasteride tablets, there is a risk of absorption through the skin, which could potentially harm a male fetus's genital development.
• Men should discontinue finasteride at least 3-6 months before attempting conception to allow for complete clearance of the medication and production of new, unaffected sperm.

Alternative Treatments

During this time, alternative treatments for hair loss or prostate issues should be discussed with a healthcare provider. Once pregnancy is achieved, men can generally resume finasteride if needed, as there is no evidence of harm through seminal fluid exposure during pregnancy, as stated in the guideline 1. However, it is essential to prioritize the safety of the fetus and the mother, and any decision to continue or discontinue finasteride should be made in consultation with a healthcare provider.

Prioritizing Safety

In the absence of clear evidence on the safety of finasteride during conception, it is recommended that men discontinue finasteride at least 3-6 months before attempting conception. This approach prioritizes the safety of the fetus and the mother, and minimizes any potential risks associated with finasteride use. By exercising caution and discontinuing finasteride before conception, men can reduce the risk of any potential harm to their partner or unborn child.

From the FDA Drug Label

Finasteride tablets are contraindicated in pregnant females and not indicated for use in females. Based on animal studies and the mechanism of action, finasteride tablets may cause abnormal development of external genitalia in a male fetus if administered to a pregnant female No developmental abnormalities were observed in the offspring of untreated females mated with finasteride treated male rats that received approximately 61 times the MRHD (based on AUC at animal dose of 80 mg/kg/day) Treatment with finasteride tablets for 24 weeks to evaluate semen parameters in healthy male volunteers revealed no clinically meaningful effects on sperm concentration, mobility, morphology, or pH.

Key Points:

• The FDA drug label does not directly address the safety of a male conceiving while taking finasteride.
• However, it does mention that finasteride may cause abnormalities of the external genitalia of a male fetus if a pregnant female receives finasteride.
• Studies in male rats showed no developmental abnormalities in the offspring of untreated females mated with finasteride-treated male rats.
• Finasteride had no clinically meaningful effects on sperm concentration, mobility, morphology, or pH in healthy male volunteers.

Answer: The FDA drug label does not answer the question.

From the Research

Finasteride and Male Conception

• The safety of finasteride for male conception is a topic of interest, particularly in relation to its effects on hormone profiles, reproduction, and sexual function 2, 3, 4, 5, 6.
• Studies have shown that finasteride, a 5-alpha-reductase inhibitor, can alter sperm parameters, including a decrease in total sperm number and an increase in abnormal forms 2.
• However, these changes were found to be temporary, and sperm parameters returned to baseline after treatment discontinuation 2.
• Finasteride has also been associated with an increased risk of sexual dysfunction, including erectile dysfunction and decreased libido 3, 4, 6.
• The mechanism of action of finasteride, which involves the inhibition of type II 5alpha-reductase, can lead to a decrease in serum and scalp dihydrotestosterone (DHT) levels, potentially affecting male fertility 5.

Dosage and Conception

• The studies reviewed used a dosage of 1 mg/day of finasteride, which is the standard dose for the treatment of androgenetic alopecia 2, 3, 5, 6.
• The question specifically asks about the safety of conceiving while taking 5 milligrams of finasteride, which is a higher dose than typically used for androgenetic alopecia.
• There is limited information available on the effects of higher doses of finasteride on male fertility and conception.

Recommendations

• Based on the available evidence, it is recommended that men taking finasteride for androgenetic alopecia be informed about the potential risks of sexual side effects and the importance of careful andrological evaluation before treatment 2, 6.
• However, the safety of conceiving while taking finasteride, particularly at a higher dose of 5 milligrams, is not well established, and further studies are needed to fully understand its effects on male fertility 3, 4.