Key takeaways
- Dutasteride improved hair counts more than finasteride in a 24-week trial, but that does not establish the best long-term choice for everyone. Randomised trial.
- Both medicines reduce the formation of dihydrotestosterone, or DHT, through related but different enzyme effects. Trial background.
- Sexual side effects and mood changes deserve attention, not dismissal as anxiety about treatment. EMA safety review.
- The EMA confirmed suicidal thoughts as a side effect of finasteride tablets in 2025; the frequency is unknown. Regulatory findings.
A circle of scalp 2.54 cm in diameter was the main measuring area in this trial. Researchers counted its hairs at week 24, measured hair width and assessed photographs, including a front view. The 917 men were aged 20 to 50 and had androgenetic alopecia. For someone wondering whether to switch, this is a six-month comparison in diagnosed male pattern hair loss. Trial methods.
This comparison concerns male pattern hair loss. Sudden shedding, isolated bald patches or a painful scalp need a different assessment.
Is dutasteride more effective than finasteride?
One substantial head-to-head trial favoured dutasteride, but its follow-up lasted only 24 weeks.
The study included 917 men with androgenetic alopecia. The tested dutasteride regimen improved hair count and width more than the finasteride comparator. Side effects reported during the trial were broadly similar between groups. This is useful evidence, but a relatively short study cannot settle uncommon risks or years of treatment. Published trial.
| Question | Finasteride | Dutasteride |
|---|---|---|
| Main enzyme action | Mainly type 2 5-alpha reductase | Types 1 and 2 |
| Evidence in the comparison trial | Improved hair growth | Greater improvement at the tested regimen |
| Does this determine an individual’s choice? | No | No |
More hair growth does not make an adverse effect acceptable. The choice needs to account for symptoms experienced during treatment as well as the scalp photographs.
Which side effects should change the conversation?
New sexual symptoms, depression or thoughts of self-harm need prompt attention.
The EMA’s 2025 review identified 325 relevant reports of suicidal thoughts: 313 for finasteride and 13 for dutasteride, with one report involving both. These were suspected adverse-effect reports, not a measured frequency. The review confirmed suicidal thoughts as a finasteride-tablet side effect; frequency remains unknown. It did not establish a direct link for dutasteride, but recommended precautionary information because of the related mechanism. Sexual problems, including reduced desire, erectile dysfunction or ejaculation problems, may contribute to mood changes. EMA review.
The measures endorsed in Europe on 19 June 2025 include a patient card for finasteride hair-loss tablets. It tells patients about mood and sexual-function symptoms and the action to take. If mood changes develop while taking finasteride for hair loss, stop the treatment and contact a doctor as soon as possible. Thoughts of self-harm need immediate emergency help; do not wait for the hair-loss review. EMA patient advice.
Give the clinician the dates of the symptoms and any medicine changes. Someone else’s success story, or a claim online that the symptoms are “nocebo”, cannot establish their cause.
What should you ask before switching?
Ask what a switch is expected to improve and how its benefits and harms will be followed.
Bring dated photographs taken in similar lighting, your treatment history and a list of adverse effects. Ask whether the prescription is for an approved indication or an off-label use in the country concerned. Overseas approval can be informative, but it does not answer that local prescribing question.
Also tell the clinician about fertility concerns, prostate investigations and other medicines. Do not use a prostate-treatment pack as a substitute for a hair-loss prescription or improvise a tablet-splitting schedule.
If you are comparing a DHT blocker with minoxidil, remember that these are different approaches. Our oral minoxidil article covers the evidence and cardiovascular considerations. Questions about testosterone and fertility are addressed separately in the enclomiphene and Clomid comparison.
Do and don’t
Do:
- Agree on a review date and use dated photographs in consistent lighting, instead of daily mirror checks, to judge progress.
- Raise sexual or mood symptoms even if you are unsure they are related.
Don’t:
- Treat greater DHT suppression as proof of greater personal benefit.
- Switch, combine or alter prescription medicines without a treatment plan.
