Finasteride and depression: what the evidence means

Reports linking finasteride with depression and suicidal thoughts have raised an important question for people treating hair loss: how should a potential mental health risk affect their choices? Research has identified a safety signal, but the studies behind these headlines cannot establish an individual’s likelihood of experiencing these symptoms.

The findings covered by Healthline in February 2021 concern an established prescription medicine, not a newly discovered treatment. For UK readers, they sit alongside subsequent advice from the Medicines and Healthcare products Regulatory Agency (MHRA), which reinforced warnings about psychiatric and sexual side effects in April 2024.

What happened

A study published in 2020 examined reports held in the World Health Organization’s international medicines safety database, drawing on submissions from more than 150 countries. Researchers identified disproportionate reporting of depression, anxiety and suicidal thoughts among younger people using finasteride for hair loss, particularly those aged 45 or under.

Disproportionate reporting means a problem appears more frequently in reports involving one medicine than expected against a comparison group. It is a way of spotting concerns that deserve investigation. It is not the same as following everyone prescribed a medicine and measuring how many develop a condition.

The analysis also found that reporting increased after 2012. That timing matters because publicity can encourage patients and clinicians to report symptoms they might previously have left unreported. Increased awareness can help uncover genuine harm, but it can also influence patterns in a safety database.

Separately, Reuters examined court documents and regulatory records concerning finasteride, sold as Propecia and in generic versions. According to Healthline’s account of that investigation, an internal Merck assessment in 2009 recorded 200 reports of depression, including suicidal thoughts, among men using the drug.

Reuters also reported that suicidal behaviour was not included in a 2011 US warning-label update. Following that decision, the US Food and Drug Administration (FDA) received more than 700 reports involving suicidal thoughts or deaths by suicide among users, including at least 100 reported deaths, by the time of the investigation.

These are historical report counts, not confirmed totals of harm caused by finasteride. Reports may lack clinical detail, and there is no reliable denominator showing how many people used the medicine during the relevant period. The figures therefore cannot be converted into a percentage risk for someone considering treatment.

The background

Finasteride treats male pattern hair loss, also called androgenetic alopecia: gradual thinning influenced by inherited susceptibility and hormones. It reduces production of dihydrotestosterone, or DHT, a hormone that contributes to the shrinking of susceptible hair follicles, the structures from which hairs grow.

Treatment can slow further loss and improve growth for some people, but benefits generally depend on continued use. Our guide to finasteride’s benefits, risks and UK prescribing advice explains the wider considerations behind starting treatment.

Getting the diagnosis right comes first. A receding hairline and progressive thinning over the crown differ from sudden widespread shedding, smooth bald patches or an inflamed scalp. These patterns can require different investigations and treatment, as our overview of male pattern baldness and when to seek help explains.

Hair loss itself can affect confidence, relationships and emotional wellbeing. That creates a challenge for researchers: depression occurring during treatment could relate to the medicine, the distress of losing hair, another health condition or several influences together. This uncertainty does not make someone’s symptoms less important or less deserving of care.

A medicines review can also uncover another explanation for shedding. According to GoodRx, some antidepressants, oral retinoids used for acne and anticoagulants, which help prevent blood clots, can cause hair loss. The likelihood and pattern vary between medicines; taking one does not mean it is responsible.

One example is telogen effluvium, when more hairs than usual move into the resting phase of their growth cycle and subsequently shed. Oral isotretinoin can trigger this in some people. Our explanation of isotretinoin-associated hair loss covers why assessment is preferable to stopping acne treatment without advice.

Antidepressants should not be stopped abruptly because of suspected shedding. Withdrawal symptoms and a return of the condition being treated are separate risks. A prescriber can assess the timing, consider other causes and discuss whether a supervised change is appropriate.