The Medicines and Healthcare products Regulatory Agency (MHRA) has updated safety advice for hair loss drug finasteride, and prostate drug dutasteride, after reviewing evidence on the risks of “sexual dysfunction, depression and suicidal thoughts”.
The MHRA announced on May 11 that it has updated the advice to “strengthen warnings about potential psychiatric and sexual dysfunction” linked to finasteride, and “provide precautionary advice” on dutasteride, a drug in the same class.
Read more: Finasteride: MHRA warns of hair loss drug ‘psychiatric and sexual side effects’
Finasteride is used to treat androgenetic alopecia - also known as male pattern hair loss - at a dose of 1mg, and benign prostatic hyperplasia at a dose of 5mg.
Dutasteride is used to “treat benign prostatic hyperplasia” at 0.5mg, and can also be prescribed off-label to treat male hair pattern loss.
The MHRA said the product information for finasteride 1mg has been updated “to clarify that sexual dysfunction may contribute to mood disorders, and that sexual dysfunction has also been reported with and without mood alterations”.
Read more: GPhC: Pharmacies to ‘verify’ patient history before supplying hair loss drug
And a “precautionary warning” added to product information for dutasteride highlights that “mood alterations have been reported” with finasteride.
The regulator said the new drug safety update follows an “additional detailed review of the evidence, including the outcome of a European regulatory review”.
The updated product information will “provide clearer guidance for healthcare professionals and patients”, it added.
“Significant action”
MHRA chief safety officer Dr Allison Cave said the regulator “has taken significant action to raise awareness of the risks of sexual dysfunction, depression and suicidal thoughts associated with finasteride, including issuing a drug safety update and introducing patient alert cards in 2024.”
“We expect prescribers to discuss the relevant safety information with patients so they can make informed decisions about their treatment,” she added.
Read more: Over £4m of illegal medicines seized in ‘intensive’ operation
The potential psychiatric and sexual side-effects of finasteride were highlighted by the MHRA in April 2024, when it issued patient alert cards after some patients reported “depressed mood, depression, suicidal thoughts and sexual dysfunction”.
It said at the time that despite the “widespread” use of the drug, there was a “lack of awareness of these potential side effects”.
Read more: MHRA and eBay remove over 200 fake ED meds from sale
More recently, data from the MHRA has shown that in the last five years, more than 65,000 doses of illegal hair loss medicines have been seized by the regulator.
A Freedom of Information request sent to the MHRA in March revealed that 27,091 doses were seized in 2025 alone, including the drugs eflornithine, finasteride and minoxidil.
