Finasteride and Dutasteride: Safety

Finasteride and Dutasteride are two of the most commonly prescribed medications by hair restoration specialists for the treatment of different types of alopecia. Although both medications have an excellent safety profile, they often raise concerns among patients. These concerns are largely unfounded and are influenced by package inserts and popular misconceptions.

The adverse effects listed for these medications are mainly related to male sexual function, including a possible reduction in erectile function, libido, and/or ejaculatory volume. However, these side effects occur only in a very small number of cases—around 3%—and usually resolve after adjusting the dosage or discontinuing treatment.

To properly understand these possible adverse effects, it is important to understand how the medications work, as well as their dosage and method of administration.

How Finasteride and Dutasteride Work

Both Finasteride and Dutasteride act as 5-alpha reductase inhibitors, an enzyme found in the roots of hair follicles (and in the prostate). These medications are highly selective and act only on these tissues, without affecting other organs. Dutasteride inhibits this enzyme more intensely and also remains active in the body for a longer period of time.

As mentioned, both medications were originally approved for the treatment of benign prostatic hyperplasia (BPH) and were introduced to the market in the 1990s. They were initially prescribed for older men, during whose treatment an improvement in hair density was observed. This led to studies confirming their effectiveness in treating alopecia in both men and women.

Side Effects: The Main Concern

Side effects are common to all medications, which is why they are listed in the package leaflet. However, the fact that a side effect appears in the leaflet does not mean that it will necessarily occur. In fact, these side effects are uncommon and usually reversible after adjusting the dosage or discontinuing treatment.

Finasteride and Dutasteride are both considered very safe medications. Adverse effects are reported in only about 3% of patients, a risk that is very similar to that observed in people who do not routinely take these medications.

The greatest concern among patients taking these medications is the possibility of reduced libido or temporary erectile dysfunction. It is important to note, however, that these symptoms were primarily observed in older patients being treated for prostate disorders. Because of their age, these patients were already more likely to experience these types of conditions. In younger patients, such side effects are very rarely observed.

Frequently Asked Questions

What should I keep in mind when taking Finasteride or Dutasteride?

You should keep in mind that these medications should only be prescribed and supervised by specialist physicians, such as Dr. Espinosa Custodio. The doctor will determine the appropriate dosage to ensure maximum safety. Both men and women may take these medications; however, it is essential to inform your doctor if you are planning a pregnancy. These medications may affect normal fetal development by reducing semen quality or affecting the eggs.

Will these medications affect my prostate?

At the doses typically prescribed for hair loss treatment, they will not negatively affect the prostate. If they have any effect, it would generally be beneficial, helping to prevent prostate-related problems.

Dr. Espinosa Custodio works at Instituto Médico del Prado, his hair clinic in Madrid, and performs hair transplants in Mexico, twice a year. If you would like to make an appointment, you can contact us on +34 912 468 664, on WhatsApp +34 627 396 322 or on the contact page of our website. From Mexico you can contact us at +52 55 4590 9909.

Bibliography

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Efficacy and safety of finasteride therapy for benign prostatic hyperplasia: Results of a 2-year randomized controlled trial (the PROSPECT study). PROscar Safety Plus Efficacy Canadian Two year Study. CMAJ., 155 (1996), pp. 1251-1259J.C. Nickel, Y. Fradet, R.C. Boake, et al. Medline

Incidence and severity of sexual adverse experiences in finasteride and placebo-treated men with benign prostatic hyperplasia. Urology., 61 (2003), pp. 579-584. H. Wessells, J. Roy, J. Bannow, et al. Medline.

Benign prostatic hyperplasia. Lancet., 361 (2003), pp. 1359-1367. A. Thorpe, D. Neal. Recuperado de: http://dx.doi.org/10.1016/S0140-6736(03)13073-5 | Medline

A review of the clinical efficacy and safety of 50alpha-reductase Inhibitors for the enlarged prostate. Clin Ther., 29 (2007), pp. 17-25. M. Naslund, M. Miner. http://dx.doi.org/10.1016/j.clinthera.2007.01.018 | Medline

Effect of 5α-reductase inhibitors on sexual function: A meta-analysis and systematic review of randomized controlled trials. J Sex Med., 13 (2016), pp. 1297-1310L. Liu, S. Zhao, F. Li, et al. http://dx.doi.org/10.1016/j.jsxm.2016.07.006 | Medline