In recent years a new, extreme sub-culture of sex and drugs has become a way of life for a growing minority of gay men. The so-called chemsex scene involves an unholy trinity of drugs – Mephedrone, GHB/GBL and Crystal Meth – and together they can keep men awake for days. These relatively new drugs are taken to enhance one thing in particular - sex. Mobeen Azar travels to San Francisco - one of the first cities to see the ‘party and play’ scene emerge - and London, where chemsex is a relatively new phenomenon and speaks frankly to men involved in the lifestyle.