A young health worker died after she took an overdose of slimming pills, each containing two-and-a-half times as much caffeine as a can of Red Bull.

Cara Reynolds had bought Forza raspberry ketone ‘natural’ supplements from Amazon to help her lose weight, even though she was a size ten, her family said yesterday.

Unproven ketone pills have been marketed on Facebook using bogus endorsements from celebrities, although Forza says it has not used such endorsements.

After splitting up with her fiance, Miss Reynolds, 24, swallowed a large number of the tablets, containing as much caffeine as 225 cans of Red Bull energy drink.

Medics tried to restart her heart more than 40 times, but were unable to save her.

A report submitted to the British Medical Journal said the tragedy highlighted the dangers of untested over-the-counter supplements. Miss Reynolds’s family yesterday called on retailers such as Holland and Barrett to stop selling raspberry ketones.

‘If the ketones had not been so readily available, Cara might still be here today,’ her father Michael, 55, said.

‘These pills need to be taken off the shelves.’

He said: ‘My entire world has collapsed since I lost my Cara. Our beautiful girl paid less than £20 and bought these pills from a website.

‘They are targeted at vulnerable, young women who already have body image issues.’

A representative for Forza said: ‘This is a tragic and understandably upsetting situation for her family and friends, but it could have been effected through the misuse of any supplement.

‘Forza products meet vigorous health and safety standards and have clear labelling and directions for safe usage.

‘It is regrettable to our client that an intentional overdose of a large number of capsules of a food supplement has potentially contributed to Miss Reynolds’ suicide.

‘The facts surrounding this incident are not yet wholly clear, but our client entirely rejects any implication that an inherent safety issue with its products is responsible.’

In February, Miss Reynolds, a support nurse, bought the raspberry ketones on the internet.

She told her parents she planned to take them to help her lose weight while working out at the gym.

Her father said: ‘She was 5’4″ and a size 10. She wasn’t overweight at all.

‘But we wanted to be supportive of her. She told us the slimming pills were made from natural ingredients, so we didn’t think they were anything to worry about.’

Devastated: Her father Michael, said many popular retailers should ban over-the-counter sales of slimming pills such as these. He said: ‘If the ketones had not been so readily available, Cara might still be here today’

After taking two pills, Miss Reynolds went to her father complaining of heart palpitations.

He said: ‘She’d only taken the recommended amount of pills but was scared because her heart was going 10 to the dozen.

‘That’s when she said she wasn’t going to take them for weight loss any more – it had really worried her.’

But a month later, on March 5, 2013, her mother saw her have a seizure and ran to her side.

Miss Reynolds admitted she had taken most of the slimming pills and was vomiting and fitting for half an hour before falling unconscious.

‘Raspberry ketones are the naturally occurring chemical compounds that give raspberries their scent.

‘They are promoted as ‘fat burners’ although there is little evidence for this.’

Raspberry ketone is a natural compound found in raspberries.

It is the chemical that gives berries their signature scent.

For years raspberry ketones were used primarly by the perfume and food industries, but the compound is also sold as a supplement.

Raspberry ketone is a natural compound found in raspberries and the chemical that gives berries their signature scent

Raspberry ketone is a natural compound found in raspberries and the chemical that gives berries their signature scent

They have been touted as a miracle weight-loss drug, with manufacturers claiming they can break down fat, helping people lose weight.

But there is no reliable scientific evidence that the ketones work to improve weight loss.

Some studies, carried out on animals, show raspberry ketones increase some aspect of metabolism.

And it is also thought to affect a hormone in the body, adiponectin.

There is not enough scientific evidence to know if raspberry ketone is safe to take as a supplement.

No human studies have been carried out to date.

However, there are some concerns about the products.

It is thought they could cause jittery feelings, increase blood pressure or a rapid heart beat.

In a report into the death of Miss Reynolds, doctors writing in the BMJ said: ”Many slimming products have concentrations of up to 250mg of caffeine per tablet.

‘This is equivalent to more than four cans of Red Bull or seven cans of Coca Cola.

After finding his daughter unconscious on her bedroom floor, Mr Reynolds noticed evidence of raspberry ketones and called an ambulance.

He said: ‘I held my only daughter in my arms and before she became unresponsive she kept telling me she had made a mistake and that she didn’t want to die.

‘She’d broken up with her fiance of one year and was left devastated by the rocky relationship.

‘In a moment of madness, she’d taken an overdose because she had the ketones to hand.

‘It was the most heartbreaking moment of my life, and one I will never forget.’

When paramedics arrived to rush her to the Royal Infirmary, Edinburgh, he told medics he had found the empty packaging by her body.

Despite 44 attempts to resuscitate her, Miss Reynolds died five hours later from cardiovascular collapse because of the fatal dose of caffeine she had ingested.

A case report of her death submitted to the British Medical Journal (BMJ) said the high dosage of caffeine sent her heart into cardiac arrest.

The report author stated: ‘This case report highlights the dangers of increasingly popular over-the-counter slimming pills.

‘Many slimming products have concentrations of up to 250mg of caffeine per tablet which is equivalent to more than four cans of Red Bull or seven cans of Coca Cola.