Why Clinicians Advise Stopping Finasteride Before Trying to Conceive

If you take finasteride for male pattern hair loss and are planning to start a family, always let your prescribing clinician know ahead of time. Finasteride can reversibly affect male fertility parameters and sexual function, which is why prescribers typically recommend pausing treatment before trying to conceive (1).

How finasteride affects DHT and male fertility

Finasteride is a 5-alpha reductase inhibitor that blocks the conversion of testosterone into dihydrotestosterone (DHT), lowering serum DHT by roughly 70% to protect scalp follicles (2). Because the prostate and seminal vesicles also rely on normal DHT signaling (3), clinical studies comparing daily 1mg finasteride users with non-users have observed lower average sperm concentration (55.6 vs. 90.6 million/mL), total motile sperm count, and semen volume (4). Reassuringly, stopping finasteride has been shown to restore sperm counts and semen quality toward baseline (5).

What about exposure during pregnancy?

Only trace amounts of finasteride pass into semen in men taking 1mg daily, and documented paternal exposures have generally resulted in healthy full-term pregnancies (8,15). However, pregnant women must never handle crushed or broken finasteride tablets, as direct systemic absorption during weeks 8–12 of pregnancy can affect male fetal genital development (8,14). Manufacturers recommend barrier protection or pausing treatment as a precaution.

Is topical finasteride safer when trying to conceive?

Phase III trial data show plasma finasteride levels are more than 100 times lower with topical spray than with 1mg oral tablets (13). However, fertility, semen concentrations, and conception outcomes have not been formally studied for topical formulations, so clinicians still advise caution when planning pregnancy.

When to stop — and hair-safe alternatives while conceiving

Because a full spermatogenesis cycle takes roughly 2 to 3 months, prescribers typically recommend stopping finasteride at least 3 months before unprotected conception attempts — no dose tapering is required (9). During this window, topical minoxidil (alone or paired with gentle scalp microneedling) offers a non-hormonal way to support follicles in the anagen growth phase without altering DHT (10,12).

References

1. NHS. Fertility and pregnancy while taking finasteride. 2023.
2. Kaufman KD, et al. Finasteride in the treatment of men with androgenetic alopecia. J Am Acad Dermatol. 1998;39(4):578–89.
3. Kinter KJ, Anekar AA. Biochemistry, Dihydrotestosterone. StatPearls; 2020.
4. Filho NM, et al. Finasteride 1 mg: Silent impacts on male fertility despite preserved hormonal balance. Journal of Urology. 2026;215(5S).
5. Irwig MS. Androgen levels and semen parameters among former users of finasteride. JAMA Dermatol. 2014;150(12):1361–3.
6. MotherToBaby / NCBI. Finasteride Fact Sheet. 2024.