Hair Loss News

A frequent question that is raised by men who want to use Propecia, Dutasteride and other DHT inhibitors to treat their hair loss is, “will it affect my ability to have children?”

Conventional wisdom has previously held that it would not and that it’s only problematic if the woman takes the drug while she is pregnant.   Some new research however has shown that DHT inhibitors, in particular Finasteride (Propecia/Proscar) and Dutasteride (Avodart), do in fact affect the quantity and motility of a man’s sperm.

In this study below, researchers found that in healthy men who were taking 5mg of Finasteride or 0.5mg of Dutasteride, there was a significant (6-12%) reduction of their sperm’s motility.   Sperm motility is the amount of movement the sperm makes.   Motility is important as far as pregnancy goes because if the sperm does not move enough, it can make it difficult for a man to impregnate a woman.

The other area that was affected was sperm count, i.e. the number of sperm present per ejaculation and the concentration of sperm.

In both treatment groups, total sperm count compared to baseline was significantly decreased at 26 weeks (6.5 months).  In Dutasteride users it had decreased by 28.6% and in Finasteride users it had decreased by 34.3%.

However after 52 weeks (1 year) things did improve slightly.   The Dutasteride group was down by 24.9%, compared to 28.6%, and the Finasteride group was down by 16.2% compared to 34.3%.

After 1 year the men’s semen volume was also decreased.   In the Dutasteride group it was down by 29.7% and in the Finasteride group it was down by 14.5%.  In addition to this their sperm concentration was decreased too.   In the Dutasteride users it was down by 13.2% and in the Finasteride users it was down by 7.4%, neither was considered to be significant.

In conclusion, it appears that DHT inhibition does affect the sperm in the following ways: decreased sperm count, decreased sperm motility, and a decreased concentration of sperm.

This does not appear to have any impact on the health of the child fathered, but rather it can make it more difficult for a man to father a child while using DHT inhibitors.   Another issue to note is that the group who used Finasteride took the 5mg dose as is present in the drug Proscar and not the 1mg dose that’s in Propecia.   While there should be less concern using Propecia, without a study there is no way of knowing exactly how different the effects would be when using 1mg of Finasteride instead of 5mg.

Lastly, the researchers stated that the effects appear reversible after discontinuation of the drugs.

The Effect of 5alpha-Reductase Inhibition with Dutasteride and Finasteride on Semen Parameters and Serum Hormones in Healthy Men.

J Clin Endocrinol Metab. 2007 Feb 13
Amory JK, Wang C, Swerdloff RS, Anawalt BD, Matsumoto AM, Bremner WJ, Walker SE, Haberer LJ, Clark RV.
Department of Medicine (J.K.A., B.D.A., A.M.M., W.J.B.), Veterans Affairs-Puget Sound Health Care System (B.D.A., A.M.M.), and Geriatric Research, Education and Clinical Center (A.M.M.), University of Washington, Seattle, WA, USA; Department of Clinical Pharmacology (S.E.W., L.J.H., R.V.C.), GlaxoSmithKline R&D, Research Triangle Park, NC, USA; and the Department of Medicine (R.S.S., C.W.) and General Clinical Research Center (C.W.), Harbor-UCLA Medical Center, Torrance, CA, USA.

Context: Dutasteride and finasteride are 5alpha-reductase inhibitors (5ARI) that dramatically reduce serum levels of dihydrotestosterone (DHT).

Objective: As androgens are essential for fertility, we sought to determine the impact of 5ARI administration on serum testosterone (T), DHT, and spermatogenesis.

Design, Setting, Subjects, and Intervention: We conducted a randomized, double-blinded, placebo-controlled trial in 99 healthy men randomly assigned to receive dutasteride (0.5 mg) (n = 33), finasteride (5 mg) (n = 34) or placebo (n = 32) once daily for 1 year.

Main Outcome Measures: Blood and semen samples were collected at baseline, at 26 and 52 weeks of treatment, and at 24 weeks post-treatment, and were assessed for T, DHT, and semen parameters. Results: Dutasteride (D) and finasteride (F) significantly (P < 0.001) suppressed serum DHT compared with placebo (dutasteride, 94%; finasteride 73%), and transiently increased serum T. In both treatment groups, total sperm count compared to baseline was significantly decreased at 26 weeks (D -28.6%, F -34.3%) but not at 52 weeks (D -24.9%, F -16.2%) nor at the 24 week follow-up (D -23.3%, F -6.2%). At 52 weeks, semen volume was decreased (D -29.7%, F -14.5%, significantly for D) as was sperm concentration (D -13.2%, F -7.4%, neither significant). There was a significant reduction of 6-12% in sperm motility during treatment with both dutasteride and finasteride and at follow-up. Neither treatment had any effect on sperm morphology.

Conclusions: This study demonstrates that the decrease in DHT induced by 5ARIs is associated with mild decreases in semen parameters that appear reversible after discontinuation.

Source: PMID 17299062