Chemsex: What the Latest Research Says About Risks and Help

Chemsex is the use of specific drugs during sex, mostly among gay and bisexual men. Researchers warn that it raises the risk of HIV, other STIs, and mental health problems. New studies from 2024 and 2025 show the practice is spreading beyond big cities. Health services across Europe are now expanding support programmes.

What is chemsex exactly?

Chemsex refers to sex under the influence of certain drugs. The main three are crystal meth, mephedrone, and GHB/GBL. Users take these drugs to lower inhibitions, extend sessions, and boost arousal. Sessions can last many hours or even days.

The term was first used in London around 2013. Since then, chemsex has become a public health topic across Europe. The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) now tracks it in multiple countries.

Not every drug use during sex counts as chemsex. Alcohol and cannabis are common but fall outside the definition. Chemsex specifically involves the three drugs mentioned above, often in combination.

How common is it?

Exact numbers are hard to find. Most data comes from surveys among gay and bi men in cities. A 2023 study in the journal Eurosurveillance found that between 3% and 15% of gay men in European capitals reported chemsex in the past year.

In the Netherlands, the Soa Aids Nederland foundation estimates around 10% of gay men in Amsterdam have used chemsex drugs. Numbers are lower in smaller towns but rising. Dating apps play a role in how people connect for these sessions.

The RIVM notes that chemsex is linked to a rise in some STIs, including hepatitis C among HIV-positive men. This link has been documented since the mid-2010s.

The health risks

Chemsex carries real medical risks. The most important ones are:

• HIV and other STIs. Longer sessions and lower inhibitions raise the chance of condomless sex with multiple partners.
• Overdose. GHB and GBL have a narrow safe dose. A small amount too much can cause unconsciousness or death.
• Injection risks. Some users inject crystal meth (called "slamming"). Sharing needles spreads HIV and hepatitis C.
• Mental health problems. Crystal meth is highly addictive. Users often report anxiety, depression, and psychosis after heavy use.
• Consent issues. Being high makes it harder to give or read consent clearly.

A 2024 study in The Lancet HIV followed 1,200 men who practise chemsex. Around 30% reported problems controlling their use. About 15% wanted help but did not know where to find it.

Why do people do it?

Researchers stress that chemsex is not simply about pleasure. Many users report deeper reasons. These include loneliness, internalised stigma about being gay, or trauma from bullying and rejection.

Dr. David Stuart, who worked at London's 56 Dean Street clinic until his death in 2022, described chemsex as often linked to shame around gay sex. His framework is still used by clinics today. The idea is that treatment must address emotions, not just drug use.

For men living with HIV, chemsex can also be about escaping the weight of diagnosis. Studies show HIV-positive men report chemsex more often than HIV-negative men.

What works in treatment?

Standard drug treatment is not always a good fit. Many general addiction services do not understand the sexual side of chemsex. That is why specialised clinics have opened in cities like London, Berlin, Amsterdam, and Barcelona.

These clinics offer a combination of care:

1. Medical support for STI testing and PrEP (HIV prevention medication).
2. Psychological help focused on sex, shame, and intimacy.
3. Harm reduction advice: safer dosing, not mixing drugs, never using alone.
4. Peer support groups where men share experiences without judgment.

The Aidsfonds in the Netherlands runs the "Mainline" project, which offers harm reduction information without pushing users to quit. Research shows this approach reaches more men than abstinence-only programmes.

Practical advice for readers

If you or someone you know is involved in chemsex, a few practical steps can lower risk:

• Get tested for HIV and STIs every three months. Regular testing catches infections early.
• Use PrEP if you are HIV-negative and have condomless sex. It cuts HIV risk by over 99% when taken correctly.
• Never use GHB or GBL alone. Tell someone where you are.
• Do not mix GHB with alcohol. The combination causes most overdoses.
• If you inject, use clean needles every time. Free needles are available at many health services.
• Talk to your GP or a sexual health clinic. In the Netherlands, GGD centres offer confidential help.

Readers may also want to know about Doxy-PEP, a new tool to prevent bacterial STIs after sex. It is often relevant for men who practise chemsex.

Where the research is heading

Scientists are now looking at long-term effects of chemsex. One question is whether repeated crystal meth use causes lasting brain changes. Early studies suggest yes, but more work is needed.

Another focus is younger users. Some research from 2025 shows chemsex is spreading among men under 25. This group often uses dating apps and may have less awareness of the risks.

There is also more attention to the mental health side. A large European project called "CHEMSEX-EU" is testing new therapy models. Results are expected in 2026.

For a wider view on sexual health issues in this group, see our piece on anal cancer screening for gay and bi men.

Bottom line

Chemsex is a real public health issue, not a moral panic. The drugs involved carry serious risks, especially GHB and crystal meth. But most men who practise it are not addicted and can benefit from clear information and non-judgmental care.

If chemsex is affecting your health, relationships, or work, professional help exists. Sexual health clinics, addiction services, and peer groups all have experience with this topic. Reaching out early makes recovery easier.