Finasteride and related 5-alpha reductase inhibitors (5-ARIs), like dutasteride, are widely considered to be the most effective treatment for male pattern hair loss. It targets a specific mechanism, the production of a hormone called dihydrotestosterone (DHT), that in men who are genetically at risk, drives a process that causes hair follicles to stop producing hair. But things can get complicated when you factor in the key role that DHT also plays in the maintenance of male sexual, reproductive and neurological health.
Many men can take finasteride without any problems, but numerous studies have shown that finasteride can cause sexual side effects in some patients. Let’s take a closer look at the most common sexual side effects associated with taking finasteride, how frequently they occur and importantly, how you might be able to minimize this risk.
Does finasteride cause sexual side effects?
It’s not common, but finasteride can cause sexual side effects in some men. The most plausible explanation for these effects is the medication’s interaction with an androgen (male sex steroid hormone) called DHT. Finasteride treats male pattern balding by blocking the enzyme responsible for converting testosterone into DHT, lowering concentrations of DHT in the body.
There are studies that suggest that higher DHT levels at the scalp are responsible for the progression of thinning hair, but it can be challenging to keep the effects of finasteride localized to this area. When you take finasteride as an oral tablet, the whole body is potentially exposed to the medication. If DHT levels in tissues such as the penis and prostate are impacted, the risk of sexual side effects may be higher. Many patients are aware of DHT’s role in the progression of pattern hair loss, but don’t realize that the hormone is also involved in the maintenance of normal male sexual and neurological health (Traish, 2020).
Whether a patient experiences side effects while taking finasteride can depend on several factors, including how the body metabolizes (breaks down) the medication and individual sensitivity to changes in DHT levels. For example, a patient might experience a decrease in serum (blood) DHT levels after starting finasteride but not experience any side effects. Or a patient might have a pre-existing health condition that already puts them at a higher risk for sexual dysfunction. For these reasons, it’s important for patients to have ongoing conversations with their doctors about treatment progress and any concerns about side effects as they come up.
What are the most common sexual side effects of finasteride?
Many men can take finasteride for hair loss without experiencing any problems, but when they do occur, the most common sexual side effects are erectile dysfunction, ejaculatory disorders and decreased libido (sex drive). It’s difficult to know exactly how frequently they occur, but one review of finasteride’s use in the treatment of benign prostatic hyperplasia suggests that finasteride causes sexual side effects in 2.1% to 38% of men (Erdimer et al, 2008).
The wide range in values reported in studies emphasizes how bodies can respond differently to medications. It’s also important to remember that most of the current literature on finasteride is focused on the safety and efficacy of the oral form of the medication. The percentages cited above don’t consider alternative forms of finasteride, such as compounded topical finasteride, which can potentially lower the risk of sexual side effects by allowing treatment to be applied directly to the scalp and reducing the amount of drug that enters the bloodstream.
Does finasteride cause erectile dysfunction (impotence)?
Finasteride may cause erectile dysfunction. It’s the most common sexual side effect reported in clinical trials of patients taking finasteride for either hair loss or benign prostatic hyperplasia. In studies comparing active treatment with finasteride to a placebo (an inactive dummy treatment), 3.4-15.8% of patients treated with finasteride reported experiencing erectile dysfunction compared to 1.7-6.3% treated with placebo (Hirshburg et al., 2016). This suggests that there is possibly a relationship between taking finasteride and an elevated risk of erectile dysfunction.
Interestingly, at least two other studies evaluating the impact of taking finasteride on sexual function reported no significant differences between International Index of Erectile Function (IIEF) scores for patients on active treatment versus those on placebo (Tosti, 2001 and 2004). The IIEF is a validated and standardized tool that clinicians can use to assess sexual interest, satisfaction, performance, and the severity of erectile dysfunction symptoms. But one of the test’s weaknesses is that it can’t distinguish between different causes of erectile dysfunction—whether it’s a physiological, or organic issue, or something psychological.
We explore the possible biological links between 5-ARI use and erectile dysfunction in another article but it’s important to acknowledge that sexual function is something that can be impacted by social and emotional factors. Here’s some food for thought: several studies have examined the impact of patient counselling about side effects and found that in cases where men were warned beforehand about the possibility of adverse effects, patients were nearly three-times more likely to report having them (Mondaini et al., 2007). These findings don’t invalidate patient concerns about side effects but draw attention to the challenges that doctors and their patients face in navigating the risks associated with treatment.
Does finasteride lower libido?
It’s possible that finasteride may lower libido in some patients. Some experts believe that this could be linked to DHT’s role in brain function. The emotional and physiological aspects of sex are controlled by the nervous system and mediated by molecules called neuroactive steroids. This group of steroids includes DHT, which is present in high concentrations in the parts of the brain that are associated with sexual desire (King and Lamb, 2006).
When finasteride is taken orally, DHT production in the brain may be impacted. A 2016 study found that scans of brain activity in participants who had taken finasteride showed abnormal activity in regions of the brain involved in sexual arousal and motivation, but brain function returned to normal once they stopped taking the medication (Basaria et al., 2016). In this study, researchers were not able to conclude whether finasteride use caused these responses.
Like erectile dysfunction, sex drive can be strongly affected by a person’s emotional state. The jury is still out on whether finasteride directly lowers sex drive and it’s important to recognize that there are other factors that may be contributing to it.
Are finasteride side effects permanent?
It’s unlikely that patients will experience permanent side effects after taking finasteride. In general, side effects resolve once patients come off the medication and DHT levels slowly return to baseline levels.
One long-term study of finasteride users found that sexual side effects occurred in less than 2% of participants and in those who initially reported side effects, these went away with continued therapy. By the fifth year of treatment, the incidence of side effects decreased to ≤0.3% and was comparable to the placebo-treated group (Mysore, 2012).
Studies like the one above provide support for the tolerability and safety of finasteride. However, there have been rare cases of people experiencing long-term side effects that don’t go away even after stopping finasteride. The phenomenon is known as “post finasteride syndrome” and its existence remains a controversial topic within the medical community.
Irrespective of whether side effects are temporary or permanent, we encourage patients to talk to their doctors about concerns around finasteride treatment and its potential impact on sexual and mental health.
How to reduce sexual side effects of finasteride
For many men, time can help with side effects. Long-term studies of finasteride users have shown that side effects do resolve with continued use of the medication. But there are other steps you can take to further lower your risk:
Try a lower dose to avoid sexual side effects
Your doctor might recommend trying a lower dose of finasteride or staggering your doses so that you take it less frequently. It’s important to consult with your doctor first before attempting to change your dosing because a dose that’s too small could end up being ineffective.
Using topical finasteride instead of oral finasteride for hair loss
Compounded topical finasteride may be an option for some patients. The active ingredient, finasteride, is mixed into a base to allow the medication to be applied to the skin. The idea is that by reducing the amount of drug entering the bloodstream, the risk of impacts to DHT concentrations is lower. Remember that compounded treatments are not FDA-approved and require a doctor’s prescription. Additionally, not all compounded topical finasteride formulations are created the same—some are better at keeping excess drug out of the body than others, so it’s important to do your research and weigh your options.
Alternative treatments for hair loss
Finasteride works well for treating pattern hair loss, but it’s not the only option. If you’re worried about sexual side effects, you may want to talk to your doctor about other treatments such as minoxidil or natural DHT blockers (e.g., saw palmetto) and whether they could be beneficial. If you are considering an alternative hair loss treatment, keep in mind that not all treatments are supported by high equality, strong evidence. If in doubt, consult with your doctor.
Getting to the heart of the problem
Patients with anxiety and or depression may also want to consider counselling to help address issues that may be contributing to sexual performance and satisfaction. Erectile dysfunction and lowered libido are complex issues that can have an enormous impact on one’s self esteem and quality of life. While medication shouldn’t be ruled out as a possible cause, we invite patients to consider other factors—even the ones that are hard to talk about and get the help that they deserve.
Takeaway: Sexual side effects of finasteride
Finasteride is commonly prescribed to help manage androgenetic hair loss and for many patients, the medication can be taken without causing sexual side effects. However, there are unfortunately individuals who have a sensitivity to the effects of DHT blockers and do experience adverse effects and others who are worried about their impact on sexual health and wellness. The fact remains that sexual side effects are uncommon and that sometimes, simply persisting with treatment can result in an improvement in symptoms. Of course, there is always the option to discontinue medication and in many cases, this also results in the resolution of sexual dysfunction.
If you think you may be experiencing sexual side effects, it’s a good idea to inform your doctor, who can provide guidance on next steps. At XYON, we understand that starting a new medication can be an adjustment and it’s normal to feel uncertain about how your body might react. That’s why we make sure that patients have access to an expert at every stage of their hair regrowth journey.
References:
Basaria, S., Jasuja, R., Huang, G., Wharton, W., Pan, H., Pencina, K., Li, Z., Travison, T. G., Bhawan, J., Gonthier, R., Labrie, F., Dury, A. Y., Serra, C., Papazian, A., O’Leary, M., Amr, S., Storer, T. W., Stern, E., & Bhasin, S. (2016). Characteristics of men who report persistent sexual symptoms after finasteride use for hair loss. The Journal of Clinical Endocrinology & Metabolism, 101(12), 4669–4680. https://doi.org/10.1210/jc.2016-2726
Erdimer, F., Harbin, A., Hellstrom, W. (2008). 5-alpha reductase inhibitors and erectile dysfunction: The connection. The Journal of Sexual Medicine, 5(12). https://doi.org/10.1111/j.1743-6109.2008.01001.x
Hirshburg, J. M., Kelsey, P. A., Therrien, C. A., Gavino, A. C., & Reichenberg, J. S. (2016). Adverse Effects and Safety of 5-alpha Reductase Inhibitors (Finasteride, Dutasteride): A Systematic Review. The Journal of Clinical and Aesthetic Dermatology, 9(7), 56–62.
King, S., & Lamb, D. (2006). Why we lose interest in sex: Do neurosteroids play a role? Sexuality, Reproduction & Menopause, 4(1), 20–23. https://doi.org/10.1016/j.sram.2006.03.007
Mondaini, N., Gonetero, P., Guibilie, G., Lombardi, G., Cai, T., Gavazzi, A., Bartoletti, R. (2007). Finasteride 5mg and sexual side effects: How many of these are related to the nocebo effect? The Journal of Sexual Medicine, 4(6). 10.1111/j.1743-6109.2007.00563.x
Mysore, V. (2012). Finasteride and sexual side effects. Indian Dermatology Online Journal, 3(1), 62. https://doi.org/10.4103/2229-5178.93496
Tosti, A., Piraccini, B. M., & Soli, M. (2001). Evaluation of sexual function in subjects taking finasteride for the treatment of androgenetic alopecia. Journal of the European Academy of Dermatology and Venereology : JEADV, 15(5), 418–421. https://doi.org/10.1046/j.1468-3083.2001.00315.x
Tosti, A., Pazzaglia, M., Soli, M., Rossi, A., Rebora, A., Atzori, L., Barbareschi, M., Benci, M., Voudouris, S., & Vena, G. A. (2004). Evaluation of sexual function with an international index of erectile function in subjects taking finasteride for androgenetic alopecia. Archives of Dermatology, 140(7). https://doi.org/10.1001/archderm.140.7.857
Traish, A. M. (2020). Post-finasteride syndrome: a surmountable challenge for clinicians. Fertility and Sterility, 113(1), 21–50. https://doi.org/10.1016/j.fertnstert.2019.11.030
