In this descriptive study, we found that drug use and chemsex practices were highly prevalent between a population attending an STI clinic. Subjects reporting drug use and chemsex were more frequently cis-men, identified as MSM, living with HIV and with a history of multiple partners or group sex. The ratio of MSM who participated in our survey closely matches the ratio of MSM attending the clinic (according to the statistics of our service, 60% of the people are MSM), and the high prevalence of chemsex detected in this group (49.3%) is slightly higher than described so far in our environment (15). Previous research in MSM living with HIV has reported a chemsex prevalence of 29.1% (16), and data from a study in 13 European cities showed a prevalence of sex-related drug consumption of 30% between MSM, including alcohol and erectile dysfunction medications (17).

Recent data have contributed to the knowledge of this issue in other settings. A French study including 680 university students and using an anonymous online questionnaire similar to ours, found a prevalence of chemsex use of 22.5%, lower compared to the prevalence in our study (33.8%). The most significant associated factors were the use of dating applications, chemsex use with a partner, pornography use, and bisexual orientation (18). Another questionnaire-based study conducted in an STI clinic in Italy found a prevalence of sex-related use of 24.7% during the last year, with a significant association between chemsex consumption and number of previous partners (>5), use of dating apps, reduced condom use and use of PEP between 96 MSM participants (19). The higher prevalence observed in our sample could be explained by the previous association between chemsex use and STIs, as all of our participants were evaluated for an STI diagnosis.

Additionally, in our study, we have found differences in drug consumption patterns according to the type of sexual partner. Other studies have also shown that among MSM, substances like poppers, mephedrone, and GHB/L (20) are the most commonly used, in consonance with our results. Among MSW, we found that cocaine and poppers were the most commonly used drugs after cannabis and alcohol, but the survey did not collect their use in the sexual context. We consider this a relevant limitation given the previous data on this question. In an online survey conducted in Canada (21) to explore how people feel when combining cannabis and sexual activity, most of the respondents used cannabis regularly and reported that when using during sex they were able to increase the intensity of their sensations. Among the differences between men and women, 50% of the women found it easier to reach orgasm compared to 31.4% of the men.

The use of drugs during sex can have detrimental effects on sexual health. It impairs the individual ability to negotiate safer sex practices, leading to a higher number of sexual partners and prolonged and intense sexual sessions (11, 15). Among MSM, participation in recent multipartner chemsex has been associated with a higher risk of syphilis, gonorrhea and chlamydia diagnosis (22), and the prevalence of sex-related drug consumption observed in our sample highlights the association between chemsex and STIs, consistent with previous studies (23–25).

Moreover, engaging in chemsex can significantly negatively affect mental and social well-being. Our survey results indicate that the participants had moderate levels of anxiety. Although we did not find differences between drug users in the HADS score, the reported consequences and experiences related to drug use included episodes of anxiety and impaired and dysfunctional sexual experiences, especially after drug discontinuation. A previous cross-sectional study of chemsex between MSM living with HIV using the HADS scale for mental health evaluation found that chemsex was associated with lower odds of depression and not associated with anxiety (26). However, other previous research links chemsex with increased levels of anxiety, depression, social isolation, stigma, violence, and addiction (26, 27). While different types of drugs have various psychological effects, international organizations identify anxiety as one of the main common symptoms (28). On the other hand, many people develop pathological drug use in an attempt to alleviate the symptoms of anxiety or stress, leading to unsatisfactory sexual relations. For such individuals, chemsex serves as an escape route (28, 29).

Our study has some limitations. The descriptive approach provides a snapshot of the participants’ characteristics and does not allow for tracking changes over time or establishing causal relationships. Participants attending STI clinics may have different characteristics and risk behaviors than those who do not seek medical care (30), implying a potential selection bias as the sample may not fully represent the general population engaging in chemsex. The reliance on self-reported behaviors collected through a self-administered interview introduces the possibility of recall bias. In addition, the ambiguity of some questions may lead to misinterpretation or social desirability bias, where subjects may underreport certain behaviors due to stigma associated with chemsex or personal beliefs about drug use and sexual behaviors. The online nature of the survey poses a limitation in terms of response rate and representativeness of the sample, as it may attract individuals with easier access to the internet, potentially excluding other subjects, such as those with lower socioeconomic status (31, 32). The non-response rate in online surveys can also be higher compared to face-to-face interviews or paper-based surveys (32).

One of the major strengths of our study is the different characteristics of the participants, including women, people living with and without HIV infection, and subjects with variable sexual orientations. It contributes to the limited research focusing on individuals engaged in heterosexual or bisexual relationships, which is an important aspect to consider in chemsex studies. This broadens the knowledge of chemsex practices beyond specific populations and provides insights into the impact across diverse groups.

The implications of this study are relevant for the design and implementation of preventive strategies, targeting chemsex practices, and addressing the psychological and social consequences of chemsex in comprehensive interventions. First, it is crucial to raise awareness among individuals about the risks and harms associated with chemsex and provide accessible testing and treatment services for STIs. Creating a supportive and non-judgmental environment within healthcare settings is essential to foster trust and communication between healthcare professionals and patients, thus facilitating early intervention and care. Additionally, collaborative work between sectors and stakeholders to effectively reach individuals engaged in chemsex is crucial, providing integrated care and addressing the multifaceted challenges associated with drug consumption (11, 15, 27). It is essential to take a balanced approach when discussing chemsex. While sex-related drugs can be associated with potential negative outcomes, such as increased risk of STIs, it is equally important to recognize the diverse motivations and experiences of those who engage in them. Many people who consume chemsex engage in chemsex to enhance their sexual experiences and connect with sexual partners (23). There are several studies in this regard conducted in the MSM population and it would be interesting to expand the boundaries of these studies to the general population. A harm reduction-oriented tone is recommended to address chemsex as a public health problem (20).

Our study emphasizes the urgent need for targeted interventions on prevention, education, and drug use support, as well as the relevance of drug consumption evaluation in clinical practice. Information and counseling can enhance individuals’ ability to be aware and minimize risk factors, encourage seeking care, and promote similar actions among their sexual partners. Future research should aim to overcome these limitations, including larger and more diverse populations, as well as evaluate the effectiveness of interventions for harm reduction and prevention in the context of chemsex.

In conclusion, we found a high prevalence of drug use and chemsex practices, which should prompt public health interventions given their potential impact on the sexual and mental health of people attending STI clinics.