In the United States and most regions outside sub-Saharan Africa, HIV is far more common in men. Of the roughly 39,200 new HIV diagnoses in the U.S. in 2023, 81% were among males. Across all regions outside sub-Saharan Africa, about 73% of new infections in 2024 occurred in men and boys. The reasons involve biology, sexual behavior patterns, injection drug use, and social barriers that keep men from getting tested and treated.
The global picture, though, is more complicated than the search suggests. Worldwide, women and girls actually make up 53% of all people living with HIV, driven largely by sub-Saharan Africa, where women account for 63% of new infections. So the pattern of HIV being “more common in men” is strongest in higher-income countries and specific risk groups.
Anal Sex Carries the Highest Transmission Risk
The single biggest biological factor is the per-act risk of HIV transmission during different types of sex. Receptive anal sex without a condom, pre-exposure prophylaxis, or treatment carries a risk of about 138 infections per 10,000 acts. That’s more than 17 times the risk of receptive vaginal sex (8 per 10,000 acts) and over 30 times the risk of insertive vaginal sex (4 per 10,000). Insertive anal sex sits at about 11 per 10,000.
These numbers explain why men who have sex with men face disproportionate risk. The rectal lining is thinner and more fragile than vaginal tissue, making it easier for the virus to enter the bloodstream during intercourse. Both the receptive and insertive partners face elevated risk compared to vaginal sex, but the receptive partner’s risk is dramatically higher.
Male-to-Male Sexual Contact Drives U.S. Cases
In 2022, male-to-male sexual contact accounted for 87% of all estimated new HIV infections among males in the United States, and 67% of all new infections regardless of gender. By comparison, heterosexual contact accounted for just 6% of new infections among men, and injection drug use accounted for 4%.
This concentration of cases isn’t because gay and bisexual men are inherently more vulnerable. It’s a compounding effect: when HIV prevalence is already high within a sexual network, each new sexual encounter carries greater odds of exposure. Combined with the elevated per-act risk of anal sex, this creates a cycle where prevalence stays high even as prevention tools like PrEP and treatment-as-prevention have made significant progress.
Injection Drug Use Affects Men and Women Differently
Men are about five times more likely than women to inject drugs, based on data from 18 countries. That means far more men are exposed to HIV through shared needles in absolute numbers. But here’s a counterintuitive detail: women who inject drugs are 1.2 times more likely than their male counterparts to be living with HIV. The median HIV prevalence among women who inject drugs is 15%, compared to 8.5% among men who inject drugs.
Safe injection practices are similar across genders, with about 92% of both men and women reporting safe practices at their last injection. The higher prevalence among women who inject drugs likely reflects additional sexual transmission risk and barriers to healthcare access that compound the risk from drug use itself.
Men Get Tested Less and Test Later
Men are consistently less likely than women to get tested for HIV. In 2017, 14% of U.S. men reported being tested in the past year, compared to 15.6% of women. That gap has persisted over time, and it means men are more likely to be diagnosed later in the course of infection, when the virus has had more time to damage the immune system and, critically, more time to be unknowingly transmitted to others.
Women also benefit from routine HIV screening during pregnancy, which creates a built-in testing opportunity that men don’t have. In many countries, clinics are perceived as spaces designed for women, particularly around reproductive health. Men in sub-Saharan Africa, where much of the research on this topic has been conducted, frequently describe health clinics as feminized environments where they feel out of place.
Masculinity Norms Create Barriers to Care
Research across multiple African countries has identified a consistent set of social pressures that keep men from seeking HIV testing and treatment. Caring too much about one’s health is sometimes viewed as a sign of weakness. Men avoid testing because they fear a positive result would threaten their identity as a provider, father, or husband. Some fear it would reveal infidelity and destabilize their marriages. Others assume they’re already positive based on their own risk behavior but avoid confirming it.
Communication plays a role too. In studies from Cameroon, Lesotho, Uganda, and Zambia, men reported that discussing HIV or sexual behavior with a wife or family member felt inappropriate. Women in these settings often couldn’t approach their husbands about testing because of household power dynamics. Couple-based testing was sometimes seen as a threat to male authority, giving women the ability to question men’s behavior in front of healthcare providers. These patterns delay diagnosis and keep men out of treatment longer, which sustains transmission within their communities.
Circumcision Reduces Risk in Heterosexual Transmission
Male circumcision reduces the risk of female-to-male HIV transmission by approximately 60%. The World Health Organization endorsed voluntary medical male circumcision as a prevention strategy in 2007, and large-scale programs in 13 eastern and southern African countries have since reached millions of men. The foreskin contains a high concentration of cells that HIV targets, so removing it reduces the virus’s entry points during vaginal sex.
This intervention is specifically relevant to heterosexual transmission and doesn’t provide the same level of protection for men who have sex with men, where rectal transmission is the primary route. In regions where circumcision rates are already high, like the United States, it plays a smaller role in the overall epidemiology.
Treatment Outcomes Are Similar Across Genders
Once men are diagnosed and start treatment, their outcomes are comparable to women’s. Over a seven-year follow-up period, cisgender men on antiretroviral therapy spent an average of 34.4 months with fully suppressed viral loads, compared to 32.3 months for cisgender women. The challenge for men isn’t treatment effectiveness; it’s getting into care in the first place. Later diagnosis means more time spent transmitting the virus unknowingly and more immune system damage before treatment begins.
The gap between men and women in HIV isn’t really about biology making men more susceptible. It’s about which types of exposure carry the highest risk, which populations have the highest prevalence, and which social forces keep people from testing and treatment. In the U.S. and similar settings, the concentration of HIV among men is overwhelmingly shaped by the high transmission risk of anal sex within sexual networks where prevalence is already elevated.