Investigation launched into hair loss pill as men report huge rise in side effects

Health watchdogs are investigating a popular hair loss drug after a three-fold increase since 2020 in men reporting serious side effects, including depression, insomnia, low libido and erectile dysfunction.

Government figures also show that the drug, finasteride, has been associated with at least 70 reports of patients with suicidal ideation as a suspected side effect.

The daily pill has been proven to regrow hair and is used by millions of men worldwide – although the exact number of users in the UK is unclear as the drug is not prescribed for hair loss by the NHS.

Previous studies have suggested that finasteride is safe and effective. But some users have reported slurred speech, gynecomastia (painful growth of breast tissue), and penile shrinkage.

Some say that symptoms persist long after treatment has stopped, a condition patients have dubbed Post-Finasteride Syndrome.

Merck & Co, the maker of finasteride, has long denied any association with serious long-term side effects, but has paid millions of dollars to settle lawsuits with US patients.

Now The Mail on Sunday has learned that the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has launched a safety review of the drug.

Finasteride is prescribed by the NHS for men with an enlarged prostate, but the review will only focus on its use in the treatment of hair loss.

Experts say the spike in side effects claims is largely due to the rise of online companies selling finasteride to treat hair loss through a personal prescription.

Patients order the drug over the Internet after completing an online questionnaire signed off by an in-house clinician.

Simon Breidert, President of the Post-Finasteride Syndrome Research Association, says: ‘Online pharmacies can freely market this drug as a quick and easy solution for hair loss.

“Men who are ashamed of losing their hair have been harassed. We need stricter rules that only doctors can prescribe finasteride, not websites.’

The MHRA has begun interviewing people who claim to have postfinasteride syndrome.

Patient advocate Ryan Clark, 56, who spoke to MHRA officials last week, says: ‘I have suffered from this horrible condition since the late 1990s and have been trying to get the MHRA to take action since 2017. People should be well informed about risks attached to finasteride before taking it. These side effects were devastating and made me worse and worse over the years.”

More than a million men use the drug in the US, including former President Donald Trump.

It works by blocking the conversion of the male hormone testosterone into dihydrotestosterone, or DHT. High levels of DHT are believed to lead to hair loss due to shrinking follicles on the scalp.

Finasteride was originally developed and taken in higher doses to treat an enlarged prostate. But users soon started seeing unexpected hair growth.

When given at lower doses in studies, more than 80 percent of men stopped losing their hair and 65 percent saw hair grow back, often within months.

Initial studies showed that in about four percent of cases, the use of finasteride can cause temporary psychological problems and erectile dysfunction. Websites selling the treatment warn that these symptoms may occur.

But post-finasteride syndrome, in which symptoms persist for months and years after stopping the drug, is hotly contested.

US health company Hims, which also sells finasteride in the UK, recently said: ‘There isn’t much high-quality scientific evidence to support its existence.’ The NHS says serious side effects are ‘rare’, occurring in less than one in 1,000 people, and does not recognize the syndrome.

However, in 2021, Reuters news agency reported that it had obtained US court documents showing that US health watchdogs had received more than 700 reports of suicide and suicidal ideation related to the drug since 2011. This included at least 100 reported suicides. The documents also revealed that Merck & Co had paid around £3.5 million to settle lawsuits brought by people claiming to be suffering from persistent side effects.

In court, Merck denied that the drug caused problems with sexual function after men stopped taking it, and was linked to mental illness. The claims were settled without admission of liability.

In a statement to Reuters, Merck said: “While consumers and healthcare professionals are encouraged to report side effects, the reaction may be related to the underlying disease being treated, or caused by another medication being taken concomitantly, or to other reasons occurred. .’

A paper published in 2020 by Baylor University in Texas examined the effect of finasteride on a group of 25 young men and found that nearly 70 percent of the study participants experienced abnormal penile reduction.

Doctors who prescribe the drug say the risk of serious side effects is rare, but add that it is irresponsible to have it dispensed through online pharmacies given its potency.

Dr. Harley Street dermatologist David Fenton regularly checks the hormone levels of his finasteride patients. He says, “The drug lowers your DHT levels, but this is a hormone that the body needs. So if someone has low levels to begin with and starts taking finasteride, you may be completely suppressing their DHT intake, which could explain many of the rare but terrible side effects.

“It is not possible for online pharmacies to monitor patients, so it is concerning how widespread the practice of companies distributing these pills to patients has become.”

28-year-old Manchester bank employee Tom Brown says he has suffered from Post-Finasteride Syndrome after starting the drug in 2012, as he started losing hair around his temples. He ordered it from abroad after completing a questionnaire.

Until 2019 he took finasteride every day. During that time, he noticed no change in his hair, so he decided to call it quits. But soon after, Tom found himself noticing symptoms he thought were side effects. “I felt so depressed. Then I started having a bunch of other extreme symptoms, including penile shrinkage, difficulty urinating, insomnia, and slurred words. This went on for years and life became a day to day struggle. My erectile dysfunction was so bad that even Viagra didn’t make a difference.”

“I started taking this drug because everything I read said there were no risks,” he says. “In the end it turned my life upside down.”

An MHRA spokesperson said: ‘We are reviewing the available evidence on the benefits and risks of finasteride. This is part of our ongoing responsibility to ensure that the benefits of all available medicines in the UK outweigh the risks.”