The STI Clinic News > HIV Transmission and Chemsex
# Friday, April 6, 2018
Posted: Friday, April 6, 2018 | Categories:

According to a 2017 report from Public Health England, HIV diagnoses are finally on the decline, 30 years after the original epidemic. In 2016, new HIV diagnoses in men who have sex with men decreased by 21% from the previous year (1). This decline has been attributed to falling rates of HIV transmission, which in turn may be associated with the availability of pre-exposure prophylaxis, a medication taken before sex to prevent infection.

Although this is encouraging news, HIV remains an issue – and particularly amongst those who practise chemsex.

Chemsex is a sexual practice whereby participants snort or swallow drugs to enhance pleasure and performance. Popular chemsex drugs include crystal methamphetamine, gamma hydroxybutyrate (GHB) and mephedrone (MCAT). An alternative form of chemsex is slamsex, which is where the drugs are injected for a more intense experience.

Chemsex is a cause for concern amongst medical professionals, as it is associated with risky sexual behaviours which can lead to the spread of sexually transmitted diseases such as HIV.

A recent article from Avert drew particular attention to this problem, noting that – while we have seen a decline in HIV diagnoses – we have also seen an increase in diagnoses of gonorrhoea and syphilis amongst men who have sex with men. The article also highlights a number of specific risk factors related to chemsex and HIV, quoting from a survey carried out by Public Health England, Imperial College London and University College London.

As noted in the article, "the survey revealed that 29.9% of gay men living with HIV reported having had chemsex in the last year, and 10.1% reported having had ‘slamsex’– where drugs are injected." The survey also revealed that men who practise chemsex are more likely to have a bacterial STIs and to practise unprotected anal sex.

This last factor is particularly concerning, as condomless anal sex is a high-risk behaviour when it comes to HIV transmission. The lining of the anus is very thin and easily broken, which means that receiving anal sex is the most risky sexual behaviour for HIV transmission; a person receiving anal sex is 13 times more likely to get infected than the person inserting their penis (2).

The popularity of slamsex is also concerning as it requires needle use, one of the riskiest behaviours for HIV transmission, along with anal and vaginal sex.

Now that the NHS has rolled out the PrEP Impact Trial across England, it’s fair to assume that certain men engaging in chemsex are also taking pre-exposure prophylaxis. However, the prevalence of STIs amongst men who practise chemsex may also suggest that certain people engaging in chemsex are not regularly visiting sexual health services for testing and treatment.

If you’re a gay or bisexual man concerned about HIV – whether or not you engage in chemsex – read on for a guide to staying safe.

Preventing HIV Transmission

As previously explained, the two most high-risk behaviours for HIV transmission are unprotected sex and sharing needles/injecting equipment.

When engaging in penetrative anal or vaginal sex with a man or woman whose HIV status is unclear, you should use condoms. Used correctly, male condoms are 98% effective and female condoms are 95% effective (4). HIV is not often transmitted through oral sex; however, it can happen. If in doubt, use condoms and dental dams for oral sex. To ensure that the condom doesn’t break, it’s a good idea to used water-based lubricants during sex; oil-based lubricants can cause latex condoms to tear.

If you inject drugs you should be incredibly careful not to share needles or other injecting equipment. If you do share equipment you may come into contact with infected blood. Talk to your GP or drug counsellor if you need information on where to get clean needles and equipment.

Depending upon your circumstances, you might also consider taking pre-exposure prophylaxis. PrEP is available on the NHS in Scotland, and is being trialled in Wales and England. PrEP comes in tablet form and is either taken every day, or on an on-demand basis. To find out more about PrEP, visit the PrEP Impact Trial site.

PrEP is available privately via various clinics. Some websites also facilitate the importation of PrEP for personal use (which is legal depending on the quantity being purchased). There is currently only one UK licensed online service allowing patients to have PrEP prescribed and that can be found here. This website can also do all of the essential monitoring required to ensure patient safety.

Lastly, if you are engaging in any behaviours that may expose you to HIV it’s a good idea to get regular tests. Early diagnosis will help you manage the infection effectively and, with the appropriate treatment, live a relatively normal life.

To order a home HIV test kit, visit our clinic.







How Our Service Works

  • Order your
    STI test online
  • Discreet package
    arrives next day
  • Provide a sample and post in pre-paid envelope
  • Access results online
How it works - order a test, provide sample and get results online


UK +44 (0)20 7125 0367



2 Wingate Business Exchange, 64-66 Wingate Square
London SW4 0AF

Registered Address

7 Tufton Street
London SW1P 3QB

The STI Clinic is owned and operated by Online Medical Services Limited. Any medical service required is contracted to be provided by Online Clinic (UK) Limited, which is licensed by the Care Quality Commission. Testing is undertaken at The Doctors Laboratory, which is registered with Clinical Pathology Accreditation.

  • The Doctors Laboratory
  • Clinical Pathology Accreditation logoClinical Pathology Accreditation no. 1954
  • Information Commissioner's OfficeData Protection Act registered
    ICO registration no. Z2782183
Visa and Visa Debit accepted Master accepted American Express accepted