Does Finasteride Have Sexual Side Effects?

Does Finasteride Have Sexual Side Effects?

Finasteride is a medication that is used by millions of men around the world as a treatment for male pattern hair loss or androgenic alopecia. It’s easy to understand why this medicine is widely used in balding men - in a number of studies and clinical trials, finasteride has proven to be a very effective mechanism to treat male pattern balding. In fact, in a study of more than 3000 men over a 3-year period, taking finasteride resulted in hair growth for 87% of participants, with reported adverse effects in only 0.7% of participants [1]. Because the listed side effects include erectile dysfunction and lowered libido, even the smallest chance of getting these side effects raises concern for many men. In this post we’ll unpack the side effects of finasteride and the likelihood of getting (and not being able to reverse) them.

We’ve all had that friend that proudly proclaims “rather no hair on my head, than being unable to perform in bed” – it’s a fair point – men often put themselves under pressure to perform sexually (hello performance anxiety), so it’s easy to understand the hesitancy to use a drug that could risk sexual prowess.

If you’re wondering: does finasteride have side effects? The answer is yes, any medication has a side effect profile, but these were thoroughly tested and understood before the medicine was made publicly available. In 2012, the FDA published a warning on the use of finasteride, citing that it may increase the risk of experiencing sexual side effects. They also said that this was very rare. So, lets dive into the science.

Sexual Dysfunction

For men using finasteride, there are reported side effects of sexual dysfunction including lowered libido, erectile dysfunction and decreased ejaculate volume. This is in a small percentage of men – and Merck, the inventors of finasteride, have published the following data:

Drug-related adverse experiences for finasteride (1 mg) in Year 1 when treating male pattern hair loss


Taking Finasteride

Not Taking Finasteride

Decreased Libido



Erectile Dysfunction



Decreased Volume of Ejaculate



Source [4]

Other long-term studies have shown that these sexual side effects occurred in <2% of men and that they disappeared if men stopped the drug or if they continued therapy. You read that right - the incidence of these sexual side effects was comparable to placebo levels at the end of 1 year of treatment and decreased to ≤0.3% by the 5th year of treatment. [5]

The Nocebo Phenomenon

A complex term to explain the adverse effects a drug can have on a patient that is not a direct result of the specific pharmacological action of a drug, but rather the fact that they have been made aware of the possibility of side effects. For finasteride, this was studied in a group of 120 men which found that a significantly higher proportion of sexual dysfunction was reported in men who were made aware of the potential side effects of finasteride. [6]

Post finasteride syndrome

You may have read online that the side effects like erectile dysfunction and lowered libido may be permanent and irreversible. This is because there have been a few research reports claiming that some of the side-effects of finasteride persist even after stopping treatment and that these side effects are irreversible. [7] Currently there is not strong enough evidence-based data to substantiate these claims and the scientific process used for the research has been heavily scrutinized by the medical community. The persistence of sexual side effects appears to be a very rare event and a true causal relationship has not been established.


A lot of the negative finasteride reviews consider using the medicine to treat benign prostate syndrome at a dose far greater than that used to treat hair loss. There are many options available to balding men - the dosage of finasteride can be adjusted for each patient to lower the risk of side effects while ensuring the treatment of hair loss. Utilising a topical form of the treatment is also a viable option. In a small study assessing the topical application of finasteride, 90% of patients treated with a finasteride and minoxidil solution experienced moderate to marked improvements in hair regrowth, with no reported adverse side effects. [8]

Should You Consider Using Finasteride?

Millions of men have used finasteride as an effective hair loss treatment with no side effects at all. The small group of men who do experience side effects have found that these typically reverse after stopping treatment or adjusting the frequency that the medicine is used. The research alleging that the side effects persist represent only a handful of reports submitted to the FDA in a more than 20-year lifespan of the drug.

The Most Important Takeaways

  1. Finasteride has been rigorously studied with proven results and is probably the best available drug to treat male pattern hair loss.
  2. There are several studies confirming its safety, especially at the dosages used for hair loss treatment. If side effects are experienced, they are most likely reversible once you stop treatment.
  3. Because the drug has a relatively long lifespan in the body, the dose can be titrated to give you the best experience with the lowest chance of side effects. 
  4. The nocebo effect has an influence in causation of side effects, so it is important to monitor the role of psychological factors on your body’s response.
  5. Treating male pattern hair loss is a cosmetic choice, not a health choice, so you don’t have to proceed with treatment. 
  6. Talk to your doctor to get a full understanding of finasteride or for any advice so that you can make an informed decision.

The articles published by &BAM are for informational purposes only and do not constitute medical advice. If you have any medical questions or concerns, you should contact your doctor.