For decades sexual health workers have concentrated on the message of always using a condom as the main tactic against the spread of HIV and other sexually transmitted infections.To get more news about buy vigrx oil, you can visit vigrxplus-original.com official website.

But certain risky behaviours are on the rise. Illegal drugs like MDMA and speed have long been used on the gay club scene. But now "chemsex" is a growing problem - parties in private homes centred on communal drug taking and sex.

The likes of mephedrone, crystal meth and GHB/GBL (or "G" for short) can increase libido and dramatically decrease inhibition and the desire to sleep.

It's impossible to know how many men have become infected with HIV while using chems, but condom-less sex is normal for many men on the chem scene. In a study published by the London School of Hygiene and Tropical Medicine, a third of men surveyed described incidents of unintended unprotected sex while under the influence of chemsex drugs.

Simultaneously, HIV infection rates are rising. One in every eight gay men in London is HIV positive.

Kiran is one of them. "Once you try a powerful drug like crystal meth, and if that's linked to sex, that's the kind of sex you're going to want. Vanilla sex just doesn't compare. Your boundaries shift."

He began using chems after a break up with his long-term boyfriend. "Sometimes I was safe but when I didn't use a condom I would see it as a cheeky risk. When I was diagnosed as HIV positive I felt there was no point in holding back at all. I began injecting crystal meth and had absolutely no boundaries. I would try anything when I was high."

A new type of drug treatment - Pre-Exposure Prophylaxis (PrEP) - could offer protection against HIV infection. People are given a combination of anti-HIV drugs tenofovir and emtricitabine - currently being sold under the trade name Truvada - before they have unprotected sex. The drug is taken as a single pill and halts the replication of the virus, stopping infection.
Dr Sheena McCormack from University College London is leading the study. "To take part gay men had to identify that they had had condom-less anal sex in the three months prior to the study and recognise that this was likely to happen again in the near future."

Just over 40% of the men on the study had used chems in the three months prior to joining the study, McCormack says. "We found no HIV infections amongst men who took Truvada during periods of risk. It is extremely effective but it does rely on human behaviour. You do have to take the pill."

The World Health Organization has recognised that PrEP could dramatically cut HIV infection rates but some critics suggest the drug could encourage condom-less sex. Taking PrEP does not offer protection against infections such as gonorrhoea, syphilis or hepatitis. So could these infections increase if the drug is made widely available?

PrEP should be used in combination with condoms, says McCormack. "There was a slight reduction is condom use among men on the trial who took Truvada but I don't think it's a problem what people do in the bedroom unless it generates an increase in infections such as syphilis, gonorrhoea and hepatitis. We didn't see that in the study. There was no increase. Most people say they have not abandoned their previous strategies."