Made for VICE by directors William Fairman and Max Gogarty, Chemsex is an eighty-minute documentary film about drug-fuelled gay sex parties, the men involved, and the risks they take with their health. While the stories and images of injecting drug use and group sex won’t have mass-market cinema appeal, the film explains why chemsex in London’s gay scene has registered on the public health radar.

The film uses powerful, personal testimonies and barely censored, documentary footage. These expose how easy access to sexually disinhibiting drugs and potentially unsafe group sex have put a new generation of gay and bisexual men at risk of HIV and hepatitis C. Vividly documented in the film is how the latest geospatial dating apps provide access to both drugs and new sexual partners. But the complex reasons why some of these men seek out and become dependent on meth, meph and GHB proves harder to document on film.

Released in cinemas in December, this film makes a timely contribution to public health debates. Chemsex got its own explainer in the BMJ editorials section this year, although the authors acknowledged that part of the problem is a lack of data and how little is really known. It’s still impossible to even estimate how many new HIV and Hepatitis C diagnoses are due to the use of new drugs such as meph and GHB and greater sexual risk taking.

The only major piece of research undertaken so far is Sigma research’s South London Chemsex study. Led by Adam Bourne, this research found that chemsex is a diverse and complex social phenomenon and warns against more simplistic social marketing strategies that target gay men while ignoring their needs. For example, lots of the men they interviewed in south London were using meph and GHB because they’re cheap, easily available and provide intense sexual pleasure – but these risky behaviours were often just the most visible symptoms of longer term sexual, emotional and mental health problems.

The film provides vivid insights, which even the best research can’t, about quite how quickly sites like Grindr and Scruff connect gay men to each other. It also documents an increasing use of cheap drugs that increase their sexual pleasure. The most vivid depiction of how addictive these behaviours are is evident when a man is captured having sex while already online looking for his next sexual partner and a new high. These overlapping, connected digital and sexual networks are what the filmmakers portray as the epicentre of a perfect storm for a new generation of HIV transmission. This in the context of improved HIV treatment in which gay and bisexual men may be more willing to take more risks.

But, the reasons why these men take risks with their health receive less attention. The underlying social drivers of drug dependency are undoubtedly more complex that depicted in the film. This is not to say that Chemsex is a superficial film: it seeks a range of people’s views and gives everyone a voice to tell their own story. It’s just that issues such as years of homophobic bullying, stigma, or the need to find a sense of belonging and escape aren’t as easy to capture on film as men lining up to have sex with each other. Chemsex, like a lot of drug use and dependency issues, is partly a cause and a consequence of mental health problems, which are less visible and amenable to documentary. This is a gay scene in the capital city of a country that’s increasingly unequal, austere and unwilling to protect vulnerable groups.

There is potential for the film’s shock value to stir up a new moral panic about drugs, social networking sites and HIV. Some critics have suggested that VICE are demonising gay men through this film. Alarmist headlines about a chemsex addiction ‘horror story’ caught on film are one example of how to further stigmatise vulnerable people and make harm reduction harder. So there is some merit in these demonisation critiques. Not least, because alcohol fuelled sex, and the sexual health fallout, is normalized across all sections of society and sexualities. There’s also nothing new about people using drugs as source of belonging, to escape or to facilitate better sex. But this isn’t just a new version of a rave scene without the dancing. Practices such as ‘pozzing up’ (knowingly becoming infected with HIV), injecting, and the risk of GHB overdose mean that a targeted – but reasoned – public health response is urgently required.

More integrated health services, like the 56 Dean Street clinic featured in the film, are needed to bridge the gaps between NHS sexual health services and drug services. Based in the heart of Soho, 56 Dean Street provides a mix of testing, advice and counselling services. But it’s the exception rather than the norm. This is one reason why the filmmakers argue that the growing popularity of chemsex in Britain represents a new health care emergency. Cuts in spending and the fragmentation of sexual health services across more than 150 local authorities means that that replicating this best practice is challenging. As well ensuring access to integrated, gay friendly health services, harm reduction policies also now need to engage with the commercial sector and intervene via gay social networking apps and websites.

Chemsex ultimately raises more questions than it answers. Why are people putting themselves at risk of HIV again after three decades of education and prevention efforts? Why did these people want to tell their stories on film? Is this just about the London gay scene? But that’s part of the point of documentary filmmaking. Despite its critics, it’s hard to see how raising the profile of this issue could do more harm than ignoring it altogether. Fairman and Gogarty get as close to both the highs and lows as is possible, even if they can’t always document the complexity of drug dependency and its less visible interconnections with mental health. David Stuart, the chemsex lead at 56 Dean Street, neatly sums up my thoughts at the end of the film when he says: “It looks like a load of gay boys getting high but it’s more complicated than that”. I recommend you watch it.

Chemsex was released in the UK by Pecadillo Pictures on December 4.