It's over 20 years since human growth hormone was first used as an anti-ageing treatment.
Back then it was the catalyst for these two men to create an entire discipline.
Ronald Klatz is chairman of the Academy For Anti-Ageing Medicine, Bob Goldman is its president.
They make their money not from selling treatments, but from spreading the word about anti-ageing.
Their company runs events like this around the world, attracting lucrative sponsorship and thousands of paying exhibitors.
It's earnt them close to 60 million dollars.
Here they're treated like the A list celebrities who support them.
But I wanted to talk to them about making money out of an industry whose credibility is questioned by many in the medical establishment.