Finasteride and dutasteride are clinically proven treatments for pattern hair loss. Most people take them without issue, but as with any medicine, side effects are possible. Knowing what to look for helps you make a confident decision and know when to get in touch with our Dermatology Team.
Before you start treatment
Read the Patient Information Leaflet. You can find a link to this in every shipment email and in the account section of your profile.
Tell your Dermatology Clinician if you have a history of depression, low mood, anxiety, self-harm or suicidal thoughts.
What side effects can occur?
The Patient Information Leaflet covers every possible side effect. Below are the key ones to know when starting treatment.
Sexual side effects
Finasteride and dutasteride can sometimes cause sexual side effects, including:
Reduced sex drive (low libido)
Difficulty getting or maintaining an erection (erectile dysfunction)
Changes to ejaculation, such as reduced semen volume
These side effects are uncommon. They often improve during treatment, or after stopping. In some people, symptoms have continued after treatment was stopped.
If you notice any sexual side effects, stop using your treatment and get in touch with your Dermatology Team for advice.
Mood and mental health changes
Finasteride has been associated with:
Low mood
Depression
Suicidal thoughts
These side effects are rare, but serious. Don't ignore them.
If you're taking finasteride or dutasteride and develop depression or suicidal thoughts, stop treatment immediately and contact your Dermatology Team as soon as possible via hello@hairandme.com.
If you have seriously harmed yourself, or feel at immediate risk of serious harm, call 999.
Are side effects permanent?
Most side effects ease after stopping treatment. Some people have reported sexual, mood-related or physical symptoms that persist — sometimes referred to as post-finasteride syndrome (PFS).
The true frequency and cause of persistent symptoms remain unclear, and research is ongoing. If anything feels off, flag it early as that's what your Dermatology Team is here for.
Can the risk of side effects be reduced?
You can help lower the risk by:
Taking your treatment exactly as your Dermatology Clinician has set out
Completing your regular check-ins on time
Flagging any concerns or symptoms early, rather than waiting
Your Dermatology Clinician may also consider topical finasteride as part of your treatment plan, if suitable. This is applied directly to the scalp and may result in lower absorption into the bloodstream compared with capsules.