But he became addicted to the fake pills - which he continued to believe were real - and earlier this year they almost killed him.

Joe had struggled with shyness in his late teens and, like many, he found moving away to university a challenge.

But when the 23-year-old returned home to rural mid Wales after his first year, mum Sarah was initially excited to see changes in him.

"I would say his personality had changed," said Sarah.

"He was much louder and almost like a little bit brash. Naively, I thought he'd just come out of his shell."

What Sarah didn't know was Joe - not their real names - had begun to self-medicate with what he believed were genuine diazepam and Xanax pills bought online in an effort to help with his anxiety.

It wasn't long before his family noticed other changes in him too.

"He go through phases of sleep walking, mood changes, very dilated pupils," said 25-year-old Alex, Joe's older sister.

"I asked him to talk to me as a sibling, I said I wouldn't say anything to mum and dad, but he never did."

When he returned to university for his second year, his mum began to get phone calls from him in the middle of the night.

"He said 'I've been using prescription drugs to try and help myself and I think it's getting out of control,'" said Sarah.

"I became aware he was buying them on the internet and that he was using them to address his mental health issues. He'd researched what he thought he needed to take - and in his mind he'd tackled the problem.

"But as things got worse I think he became very afraid that he was being overtaken by the addiction."

When he was at home normal-looking packages would arrive for him - inside were what he believed to be prescription drugs. He eventually showed his mum them, hoping to reassure her.

Prescription drugs have to be prescribed by your GP but many people, like Joe, are going online to buy pills that they believe are legitimate to avoid consulting with a doctor.

"It was mostly diazepam," she said. "It was in fully printed and marked packaging with batch numbers, dates and the information leaflet inside.

"To me they were the genuine drugs - and to Joe they were the genuine drugs.

"He used to say to me 'I know not to take too many, I know how many I should take, I'm in control, don't worry mum.'

"It didn't for one minute enter my mind that it wasn't what it said on the tin."

However the pills weren't what they claimed to be.

According to drugs testing lab Wedinos, between 45% to 65% of benzodiazepines sent in for testing, which include diazepam and Xanax, are actually fakes.

These pills can use unregulated and much stronger ingredients, frequently leaving users with pills up to 10 times stronger than what they think they are taking.

Joe had no idea the pills he was taking were fake. Earlier this year his mum went to wake him, only to find he had overdosed.

"I could see as soon as I approached the door that he was lying across his bed," recalled Sarah.

"The look of him, the feel of him, it just said to me 'he's dead, he's gone.'

"I just became hysterical. There was no-one in the house. I dialled the emergency services - and I couldn't speak - I was just shouting."

The paramedics battled to save Joe's life for hours. Eventually a decision was made to try to move him to hospital.

Sarah was told he could die on the way down the stairs, let alone the long journey to the nearest emergency department.

Joe had suffered a cardiac arrest. He survived, but suffered major brain damage.

"The prescription drugs that Joe had been buying on the internet were not legitimate," she said.

"It wasn't what he believed, and I believed, was in the tablets.

Some drugs charities in Wales say referrals for benzodiazepines have gone up 150% in the past year, with many warning about the dangers of buying pills online.

"It is incredibly easy to be deceived," said Josie Smith, national lead for substance misuse at Public Health Wales.

"We're seeing very clever marketing of tablets that look exactly as you would find from a prescribed medication. Even in the blister packs, with the packaging, it can look really like a medication.

"Certainly in the past few years, not only in Wales but also right across in Europe, we know these drugs have become incredibly easy to obtain. They're highly available, even promoted through particular website or social media.

"I think that's the challenge that we need to address, to inform and to increase awareness around the risk of not knowing what it is that you're taking - even if it looks like something you've been prescribed in the past."

For Joe, just 23 and still - several months later - fighting for his life, it is too late.

But his family are speaking out in the hope of raising awareness.

"Joe's story is still unfolding," said his sister Alex.

"But if we can help even one family, to not go through what we're going through, then that would be job done."

The names of Joe and his family have been changed to protect their identities.