Robb Dixon regularly comes across social media posts from men eager to find solutions for thicker hair. He often feels compelled to advise them against it, believing it’s not worth the risk.

At 33, Robb, a music producer from Winchester, Hampshire, says he experienced erectile dysfunction, depression, anxiety, and various other issues after using finasteride for six months when his hair began to thin in his 20s.

The symptoms lasted for years after he stopped the medication.

‘I wanted more hair but paid with my health – it’s as simple as that,’ he says. ‘I wish I’d never taken it.’

His experience is not unique, leading to calls for better warnings about the drug’s potential side-effects.

Due to these concerns, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has issued a warning on the medication’s patient leaflet regarding potential risks of depression, suicidal thoughts, and sexual dysfunction.

Yet some experts believe warnings are still not clear enough.

Finasteride was originally developed to treat an enlarged prostate, thought to be hormone driven.

The drug works by stopping testosterone from being converted into another hormone, dihydrotestosterone (DHT), which prevents the prostate from growing too large.

DHT also shrinks hair follicles and can lead to thinning hair in some men – so reducing its levels also reduces the hormone’s effect on hair follicles, helping to stop further loss and in many cases, promoting new growth.

The drug is available on the NHS to treat prostate conditions but not for hair loss, as it’s considered a cosmetic treatment, rather than a medical one.

However, finasteride is widely available online and through private clinics to treat thinning hair – which is how Robb first came across finasteride when searching online for ways to combat his receding hairline aged 24 in 2016.

A quick Google search suggested two hair-loss treatments: finasteride, a daily pill, and minoxidil, a topical lotion that needed twice-daily application.

The pill seemed the easier option, so Robb went on to the Boots website, filled in an online form – and three days later the medication arrived in the post.

The medication leaflet did warn that it could in rare cases, cause depression, anxiety and reduced libido.

‘But I was a fit 24-year-old man and I had no history of mental illness – so I didn’t think it could happen to me,’ Robb recalls.

‘Besides, if that did begin to happen I’d stop and I thought all would be well.’

Within just 24 hours of beginning the medication, Robb noticed his libido had dramatically reduced and he couldn’t maintain an erection.

Hoping this was temporary Robb – who didn’t have a girlfriend at the time – carried on taking the medication. Within two weeks, his libido had vanished entirely and he could no longer get an erection at all.

‘I felt ashamed, worried, confused and upset,’ he says.

His hair wasn’t growing back either – so after six months, still suffering sexual problems, Robb stopped taking finasteride.

Just 48 hours later he woke in the middle of the night with ‘the worst panic attack ever’.

‘I was sitting bolt upright, sweating, panicking and with a hideous sense of dread. I also got blaring tinnitus,’ he recalls.

‘A few hours later I noticed my genitals were shrunken and retracted and I was having to urinate every 15 minutes,’ says Robb, who went straight to A&E the next morning.

‘By now I was also suffering a disassociation – I felt disconnected as though I was watching myself move through the world, interacting with people. I felt I was having an out-of-body experience. It was terrifying.’

Hospital tests revealed nothing, so he saw his GP later that week.

By this time, he was also having suicidal thoughts, joint pain and his vision was ‘blurred and snowy’.

The GP ordered blood tests to check his hormone levels, which also revealed nothing. Robb told him he was taking finasteride ‘and he looked at me blankly,’ he recalls. ‘He didn’t seem to have a clue.’

Within the next few weeks, Robb continued to suffer with ‘dreadful thoughts and anxiety’, as well as the tinnitus.

His digestive system was now also causing problems: ‘I was having bowel movements of completely undigested food for days,’ he says. ‘I couldn’t go out. I was unable to work. It was hell.’

After begging his GP to refer him to a specialist, Robb weeks later finally spoke to an endocrinologist, who’d heard of other men experiencing similar side-effects after stopping taking finasteride – ‘but he too was unable to help,’ he recalls.

Within weeks, Robb went from being ‘a muscular, fit young man’ to having no strength and feeling as though his muscles were ‘spongy’.

Robb recalls: ‘No one was able to help me. I felt angry at how easy it had been to get hold of this drug and feared for my future. I worried I’d never feel normal again.’

His experience is not uncommon. A study published in 2020 looking at the effect of finasteride in a group of 25 young men by Baylor University in the US found nearly 70 per cent had experienced penis shrinkage.

David Healy, a retired professor of psychiatry who is an expert on drug side-effects, says it’s not known why finasteride can trigger suicidal thoughts and long-term sexual dysfunction in some men.

‘There have been concerns about finasteride for a long time,’ says Professor Healy, whose book, Pharmageddon, delves into corruption in the pharmaceutical industry.

‘I have two medical colleagues who became suicidal on it when used for hair loss and one committed suicide.

‘There is no question but that it can make people suicidal and the PFS Foundation [the Post-Finasteride Syndrome Foundation, a non-profit organisation which supports individuals affected by side-effects of the drug] has been campaigning on this for a long time.’

Some men have sexual dysfunction and depression while taking the drug, but not afterwards: others have permanent side-effects even after they stop taking it, says Professor Healy – this is known as post-finasteride syndrome.

He adds: ‘The problem for those considering the medication is that there is no way of knowing if you might be affected or not – not all men who take finasteride are affected the same way.’

Worse, says Professor Healy, ‘we have no treatment for the sexual dysfunction these drugs can cause even once someone stops taking them.

‘It can sometimes recover spontaneously – but for many, the effect is permanent.’

Numerous reports from patients led to a safety review by the MHRA, which in April 2024 concluded that the drug was associated with ‘depression, suicidal thoughts and sexual dysfunction’ – as a result it introduced ‘a patient alert card’ to be included inside packs of finasteride, highlighting these risks and informing them of what to do if they experience these side-effects.

‘As patients may not notice changes to their mood, they are encouraged to show this card, and the patient leaflet, to friends and family,’ it noted.

Dr Alison Cave, chief safety officer at the MHRA, told Good Health that the new cards ‘aim to raise awareness among men taking finasteride about the potential for psychiatric and sexual side-effects so they can make an informed decision about their treatment and know what to do if they experience these side-effects’.

She added that anyone taking the drug for hair loss who develops such side-effects should immediately stop taking it and contact their doctor. Those taking the drug for prostate enlargement should also discuss side-effects with their GP or health professional.

‘Remember to always read the label inside the pack as it includes important information on how to take finasteride and its possible side-effects,’ says Alison Cave.

But as Robb points out, this is of no help when the damage is already done. ‘This advice is vacuous,’ he says. ‘It is of no help to someone who is already suffering from this.’

Thorrun Govind, a pharmacist based in Manchester and the former chair of the Royal Pharmaceutical Society, adds that health professionals should ask patients about any history of suicidal thoughts before prescribing the drug – and monitor them for potential side-effects once treatment starts.

She also advises anyone taking finasteride to tell their family or friends they’re taking the drug so they can also be alert for any mood or behaviour changes.

But Professor Healy is underwhelmed by the MHRA response.

He believes that MHRA guidelines are still inadequate on finasteride, as well as for SSRIs (selective serotonin reuptake inhibitors – drugs used to treat depression) and isotretinoin (to treat acne) – which have been linked with suicidal thoughts and sexual dysfunction in both sexes.

‘We have known about these problems for 40 years and the MHRA is only now getting around to alerting people about the risk – and not doing a particularly good job to date.’

He adds: ‘As for online prescribing, it is not clear that our systems are able to get the horse back in the stable – it may have bolted.

‘If this is the case, politicians need to start thinking about what warnings on essentially over-the-counter medicines should look like.

‘Online sales should be blocked until the patient has signed a form stating they have been informed of a serious risks of suicidal and permanent sexual side-effects – and the people prescribing and sending the medicine to them also sign a form saying they have warned about this.’

A spokesman for Boots told Good Health: ‘Patient safety is our number one priority. We prescribe finasteride through the Boots Online Doctor hair loss service and are sorry to hear of the experience of this patient. We encourage all patients experiencing any side-effects from any prescription-only medication to contact their prescribing clinician or pharmacist as soon as possible.

‘Boots Online Doctor ensures that patients prescribed finasteride are made aware of , and have confirmed that they understand, the possible side-effects of this prescription only medicine, in line with the latest information and guidance from the MHRA.’

Not everyone even agrees that finasteride is the most effective treatment for hair loss.

Steve O’Brien, a trichologist at the London Centre of Trichology, says he’s often asked about the drug by young men, drawn by the fact it’s relatively inexpensive (at £10 to £20 per month) and easy to take.

But he warns that it ‘works better at maintaining growth rather than making hair grow stronger or thicker’ and says that his clinic has never recommended finasteride ‘due to the serious potential side-effects’.

He adds: ‘We use natural lotions containing plant extracts on our patients that work better – with no side effects.’

Thankfully, four years after he stopped taking finasteride, in 2020, life finally improved for Robb as his sexual function gradually began to return, at the age of 28.

He met Rhian, now 45, and the couple married last year.

To begin with, he had to take Cialis (similar to Viagra) to maintain an erection and told Rhian about his post-finasteride syndrome. ‘She was very supportive and it made us closer,’ he says.

But even now he suffers with joint pain, fatigue and brain fog, as well as muscle wastage despite regularly training in the gym and eating healthily.

‘I still have snowy vision like an old TV set and chronic fatigue,’ he says.

Last year he co-founded the charity SIDEfxHUB to help those affected by finasteride or post-SSRI sexual dysfunction. Ironically since stopping the medication, his hair loss halted. He now also uses hair fibres to cover where the thinning was at its worst. But he stresses hair loss is something he wishes he had accepted rather than going through all he has gone through.

‘I should never have taken the finasteride in the first place.’

His message for others considering finasteride to combat hair loss is simple: ‘You cannot comprehend the levels of suffering this medication can bring.

‘No man should risk his health for a head of thicker hair. More awareness needs to be made of the risks of these medications for men.’

For more information visit sidefxhub.com