Bodybuilders in Brazil are risking death by injecting themselves with a potentially lethal cocktail of oil and alcohol to pump up their muscles.
Arlindo de Souza has grown 29in biceps - the biggest in Brazil - after injecting the filler into his body, where it causes appearance of swollen muscles.
But even he admits it can cause dangerous infections. Some users have had their arms amputated. Others have died.
'My friend Paulinho, he passed away from doing these things,' said Mr de Souza. 'I felt his death a lot. He took it, I took it, but he went beyond the limit. I advise no-one to take this oil.
'I've stopped taking it, and other things as well, but there is always that will to start again. But I'm managing to control myself, to this day.'
The Arnold Schwarzenegger fan, nicknamed 'The Mountain' in his hometown, had already been taking a cocktail of steroids, hormones and horse vitamins to bulk up.
Then a gym buddy offered him a 'site enhancement oil' to help pull ahead of his rivals.
'The guy gave it to me. He said, "Take this, it will make you grow in days",' said Mr de Souza, who is single and lives with his elderly mother, Josefa Gomes de Souza, in Olinda on the coast of Brazil's Pernambuco state.
'I loaded the syringe, put it in my arm, injected it and it swelled me up right there and then.
'To tell you the truth, I didn't feel a thing. There was sometimes a bit of dizziness but nothing apart from that.
'I was working out the same so my strength stayed the same - nothing changed.
'Most people who take it do not know how to apply it. They will use just any old blood vessel. Some will end up loosing an arm, another needs an operation, some may even lose their lives.'
Injecting site enhancement oils carry the risk of infection and of abscesses developing in the muscle. These abbesses can grow and spread within the tissue.
Some users, when operated on, have been found to have arms full of pus and oil.
Mr de Souza has fears for his own health and has visited a clinic for help. But medics have so far refused to operate because 'he did it to himself'.
The oil concoction Mr de Souza injected is believed to contain mostly mineral oil, which is similar to baby oil but unscented, and smaller amounts of alcohol and anaesthetic.
Worryingly, he has said it can easily be bought online or under-the-counter at rogue pharmacies.
And, though he has stopped using and warns others to stay away from it, he says it is continuing to sweep across body-conscious Brazil and South America.