Does Finasteride have side effects?
As with all medicines, Finasteride can cause side effects, although not everyone will experience them. Most are uncommon, and mild side effects often ease as your body adjusts to the medication. If side effects persist or trouble you, speak to your doctor or our pharmacy team.
Uncommon side effects (may affect up to 1 in 100 people):
- Reduced sex drive (decreased libido)
- Erectile dysfunction (difficulty getting or maintaining an erection)
- Ejaculation problems, such as a reduced volume of semen
- Depression or low mood
Other reported side effects (frequency not known):
- Breast tenderness, swelling or enlargement
- Testicular pain
- Anxiety
- Heart palpitations
- Blood in the semen
- Changes in liver function (detected through blood tests)
- Male infertility and/or reduced semen quality
- Persistent sexual side effects such as erectile dysfunction, reduced libido or ejaculation problems, that continue after stopping treatment
Important: mental health and Finasteride
Recent MHRA guidance highlights that Finasteride has been associated with depression, low mood and suicidal thoughts.
Stop taking Finasteride immediately and contact your doctor as soon as possible if you develop depression or suicidal thoughts.
Because some mood or behaviour changes can be hard to notice yourself, it can help to let people close to you know you have started this medication so they can help you spot any changes early.
Sexual side effects
Sexual side effects such as reduced libido, erectile dysfunction and ejaculation problems are uncommon. In most men these resolve after stopping treatment, but there are reports of sexual side effects persisting after Finasteride is discontinued.
Breast changes
Speak to your doctor promptly if you notice any lumps, pain, swelling or enlargement in the breast area, or any nipple discharge. These can be signs of a serious condition, including male breast cancer.
Allergic reaction
Some people may have an allergic reaction to this medication. Stop taking Finasteride and seek medical attention immediately if you experience:
- Skin rash, itching or hives (lumps under the skin)
- Swelling of the lips, face, tongue or throat
- Difficulty breathing or swallowing
Reporting side effects
This is not a complete list of side effects. Always read the Patient Information Leaflet supplied with your medication.
You can report suspected side effects directly through the MHRA Yellow Card Scheme. You can also tell our team, who can report on your behalf.