Do Hair Loss Medicines Affect Sexual Function? What Is Known About Erections, Sex Drive and Sperm

A young man who has started, or is considering, a hair loss medicine comes across forum stories such as “this drug ends your sex life” and asks: “Am I putting my sex life at risk while trying to keep my hair, and if I stop the medicine, will everything go back to normal?” Some never start treatment because of this worry; others stop the medicine on their own after a minor change.

The main group of medicines taken by mouth for male pattern hair loss is called 5-alpha reductase inhibitors. This article covers how these medicines work, the sexual side effects seen in controlled studies, the nocebo effect, complaints that persist after stopping, the mood warning, sperm, topical forms, the PSA test and what to do if complaints arise.

How do these medicines work in male pattern hair loss?

In male pattern hair loss, DHT (dihydrotestosterone), a potent derivative of testosterone, acts on genetically susceptible hair follicles; over time, DHT makes these follicles shrink and produce thinner, shorter hairs. 5-alpha reductase inhibitors suppress the enzyme that converts testosterone into DHT. With the tablet form, the DHT level in the blood falls by about 65% within the first 24 hours.

These medicines do not “cut off” testosterone; they do not stop testosterone production, they only reduce the conversion of part of it into DHT. Testosterone in the blood stays within the normal range and may even rise slightly. The same group is used at a higher dose for prostate enlargement; that topic is covered in a separate article on our site.

How often do sexual side effects occur in controlled studies?

In the placebo-controlled studies of the hair loss tablet, the first-year rates were as follows:

• Reduced sex drive: medicine 1.8%, placebo 1.3%
• Erection problems: medicine 1.3%, placebo 0.7%
• Reduced ejaculate volume: medicine 0.8%, placebo 0.4%

In the first year, 3.8% on the medicine and 2.1% on placebo reported at least one sexual complaint; the difference is real but small, and the vast majority of men are unaffected. The complaints resolved in men who stopped the medicine and in most of those who continued, and by the fifth year the frequency of each had fallen to 0.3% or below. However, a 2015 analysis in JAMA Dermatology noted that these studies may not have asked about sexual side effects thoroughly enough.

What is the nocebo effect, and why are forum stories so frightening?

The nocebo effect is when expecting a side effect makes you more likely to feel it. In a study published in the Journal of Sexual Medicine in 2007, men starting a medicine from this group for prostate enlargement were not told the name of the drug, and the possible sexual side effects were explained to only one group. After one year, the proportion reporting at least one sexual complaint was 43.6% in the informed group and 15.3% in the uninformed group.

This finding does not show that the complaints are “imaginary”; it shows that anxiety and expectation can genuinely affect sexual function. The study was small and was not carried out at the hair loss dose. Because forum posts come mostly from people who have had problems, the majority without problems go unheard and the risk can seem larger than it is.

Do the complaints go away when the medicine is stopped?

In most people, the complaints settle when the medicine is stopped. On the other hand, some people report problems with sex drive, erections or ejaculation that last for months after stopping. In 2011 and 2012, the US Food and Drug Administration (FDA) had the product information updated with reports of sexual side effects continuing after discontinuation, but stated that a cause-and-effect relationship with the medicine had not been established. The frequency and cause of this picture are scientifically debated; the data rely mostly on spontaneous reports. Even so, the distress is real and should be taken seriously.

The FDA product information, updated in 2022, also lists depression and suicidal thoughts among post-marketing reports. In May 2025, the safety committee of the European Medicines Agency (PRAC) accepted suicidal thoughts as a side effect of unknown frequency for the tablets of one medicine in this group, recommended a patient card for the hair loss tablets and stated that the benefits continue to outweigh the risks. So, if while taking the medicine you notice a marked change in your mood, low mood or thoughts of harming yourself, stop the medicine and see a doctor without delay.

Are sperm and fertility affected?

In a 48-week placebo-controlled study in healthy young men (Journal of Urology, 1999), the hair loss dose was reported not to affect sperm and semen production significantly. By contrast, in an observational study of men taking this medicine who sought help for infertility, sperm counts rose markedly in most after stopping (Fertility and Sterility, 2013). The product information also includes reports of reduced semen quality and of improvement after stopping.

• Couples planning a child: Continuing or pausing the medicine should be discussed with a doctor; in men with borderline sperm values, a semen analysis can guide this.
• Contact during pregnancy: Broken or crushed tablets should not be handled by women who are pregnant or may become pregnant; the active substance can be absorbed through the skin and affect the development of a male baby's external genitals. Intact, coated tablets do not lead to such contact in normal handling.

Are lotions, sprays and vasodilator products safer?

The spray or lotion forms of these medicines applied to the scalp pass into the blood less than the tablet. In a controlled study published in 2022, blood levels of the medicine with the spray were more than 100 times lower than with the tablet, and the fall in blood DHT was 34.5% versus 55.6%. However, the effect is not zero: in April 2025, the FDA announced 32 adverse event reports received in 2019–2024 for pharmacy-prepared topical products, including sexual and psychological complaints. Long-term evidence is limited, and transfer of the product to women should be avoided.

There is no strong evidence that hair products with a vasodilator (blood-vessel-widening) effect impair sexual function; there are only isolated case reports. The tablet form of this group, which is used off-label for hair loss, can lower blood pressure, speed up the heart rate and cause fluid retention (oedema); medical monitoring of blood pressure and the heart is needed.

What should you know if you are having a PSA test?

PSA is a blood test used in monitoring prostate disease and in cancer screening. 5-alpha reductase inhibitors lower the PSA value. In a controlled study published in Lancet Oncology in 2007, covering 355 men aged 40–60 with hair loss, after 48 weeks PSA had fallen by about 40% in the 40–49 age group and by about 50% in the 50–60 age group.

For this reason, always tell your doctor that you are taking a hair loss medicine at a prostate check or when having your PSA measured. The product information recommends roughly doubling the result when interpreting it; a confirmed rise while on the medicine should be investigated even if the value looks “normal”.

How are complaints assessed?

If you notice a sexual complaint, talk to your doctor rather than stopping the medicine on your own. When the medicine is stopped, the gain in hair can be lost within about 12 months; it also needs to be established whether the complaint stems from the medicine or another cause. In young men, too, erection problems can be linked to stress, sleep, weight, smoking or relationship difficulties. The assessment covers:

• Timing: how the complaint relates to the medicine, and sexual function before the medicine
• Blood-vessel health: factors such as blood pressure, blood sugar, cholesterol and smoking
• Hormones: testosterone and related hormone levels where needed
• Mood: anxiety, depression and performance anxiety

Whether to continue treatment, switch to a topical form or choose another option is a decision for dermatologists and urologists to make together.

When should you see a doctor?

A urology and andrology assessment is advisable in the following situations:

• If, after starting a hair loss medicine, there has been a change in sex drive, erections or ejaculation that bothers you
• If your complaints have continued for months even though you have stopped the medicine
• If you are planning to have a child, or if pregnancy has not occurred after more than a year of trying
• If you notice breast tenderness, enlargement or a lump, or pain in the testicles
• If you are going to have a PSA test, or if your PSA value has risen while on the medicine
• If marked low mood or thoughts of harming yourself have appeared (if there is danger, this is an emergency; 112)

5-alpha reductase inhibitors work in male pattern hair loss by reducing DHT; in controlled studies, sexual side effects were seen in a small minority of men and in most cases settled when the medicine was stopped. Persistent complaints and changes in mood should be taken seriously, and sperm, contact during pregnancy and PSA interpretation discussed with a doctor. Assoc. Prof. Zülfü Sertkaya practises in urology and andrology in Istanbul; assessment of sexual complaints related to hair loss medicines is carried out on an individual basis and in confidence.

Frequently Asked Questions