Men who have sex with men (MSM) refers to all men who engage in sexual activity with other men, regardless of sexual identity.[1] The term was created by epidemiologists in the 1990s, to better study and communicate the spread of sexually transmitted infections such as HIV/AIDS between all sexually active males, not strictly those identifying as gay or bisexual, but also for example male prostitutes. The term is often used in medical literature and social research to describe such men as a group. It does not describe any specific kind of sexual activity, and which activities are covered by the term depends on context. An alternative term, males who have sex with males is sometimes considered more accurate in cases where those described may not be legal adults.[1]

As a constructed behavioral category

The term men who have sex with men had been in use in public health discussions, especially in the context of HIV/AIDS, since 1990 or earlier, but the coining of the initialism by Glick et al. in 1994 "signaled the crystallization of a new concept."[2][3] This behavioral concept comes from two distinct academic perspectives. First, it was pursued by epidemiologists seeking behavioral categories that would offer better analytical concepts for the study of disease-risk than identity-based categories (such as "gay", "bisexual", or "straight"), because a man who self-identifies as gay or bisexual is not necessarily sexually active with men, and someone who identifies as straight might be sexually active with men. Second, its usage is tied to criticism of sexual identity terms prevalent in social construction literature which typically rejected the use of identity-based concepts across cultural and historical contexts. The Huffington Post postulates that the term MSM was created by Cleo Manago, the man who is also credited for coining the term same gender loving (SGL).[4]

MSM are not limited to small, self-identified, and visible sub-populations. MSM and gay refer to different things: behaviors and social identities. MSM refers to sexual activities between men, regardless of how they identify, whereas gay can include those activities but is more broadly seen as a cultural identity. Homosexuality refers to sexual/romantic attraction between members of the same sex and may or may not include romantic relationships. Gay is a social identity and is generally the preferred social term, whereas homosexual is used in formal contexts, though the terms are not entirely interchangeable. Men who are non-heterosexual or questioning may identify with all, none, a combination of these, or one of the newer terms indicating a similar sexual, romantic, and cultural identity like bi-curious.

In their assessment of the knowledge about the sexual networks and behaviors of MSM in Asia, Dowsett, Grierson and McNally concluded that the category of MSM does not correspond to a single social identity in any of the countries they studied.[5] There were no similar traits in all of the MSM population studied, other than them being males and engaging in sex with other men.

In some countries, homosexual relationships may be illegal or taboo, making MSM difficult to reach.[6][7]

The term's precise use and definition has varied with regard to transgender and intersex people, who do not fall neatly into binary sex categories.[8]


Determining the number of men who have ever had sex with another man is difficult. Worldwide, at least 3% of men have had sex at least once with a man.[9]

In the U.S., among men aged 15 to 44, an estimated 6% have engaged in oral or anal sex with another man at some point in their lives, and about 2.9% have had at least one male sexual partner in the previous 12 months.[10]

Sexual practices

Main article: Sexual practices between men

Men kissing intimately

Historically, anal sex has been popularly associated with male homosexuality and MSM. However, many MSM do not engage in anal sex, and may engage in oral sex, frotting or mutual masturbation instead.[11][12][13] Among men who have anal sex with other men, the insertive partner may be referred to as the top, the one being penetrated may be referred to as the bottom, and those who enjoy either role may be referred to as versatile[14]—with those who do not prefer/practice anal sex being referred to as side.

Number of sexual partners

A 2007 study reported that two large population surveys found "the majority of gay men had similar numbers of unprotected sexual partners annually as straight men and women."[15][16] According to the 2013 NATSAL (a representative population study in the UK), MSM typically had 17 lifetime sexual partners (median), which included all forms of sexual contact including oral and anal sex.[17] An epidemiological article in The BMJ reported that national probability surveys like the NATSAL have been found to better reflect the population of MSM but are limited by their smaller samples of MSM. Convenience sample surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviors.[18]

Health issues

Main article: Healthcare and the LGBT community

The examples and perspective in this section may not represent a worldwide view of the subject. You may improve this section, discuss the issue on the talk page, or create a new section, as appropriate. (January 2018) (Learn how and when to remove this template message)

Sexually transmitted infections

Main article: Sexually transmitted infection

Among men who have anal sex with other men, anal sex without use of a condom is considered to be high-risk for STI transmission. A person who inserts their penis into an infected partner is at risk because sexually transmitted infections (STIs) can enter through the urethra or through small cuts, abrasions, or open sores on the penis. Also, condoms are more likely to break during anal sex than during vaginal sex. Thus, even with a condom, anal sex can be risky.[19][20][21]


Main article: HIV and men who have sex with men

Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV).[22][23][24] HIV can infect anybody, regardless of sex, ethnicity, or sexual orientation.[25] Worldwide, an estimated 5–10% of HIV infections are the result of men having sex with men.[26] However, in many developed countries, more HIV infections are transmitted by men having sex with men than by any other transmission route.[25] In the United States, "men who have had sex with men since 1977 have an HIV prevalence (the total number of cases of a disease that are present in a population at a specific point in time) 60 times higher than the general population".[27]

In 2007, the largest estimated proportion of HIV/AIDS diagnoses among adults and adolescents in the U.S. were men who have sex with men (MSM). While this category is only 2% of the U.S. population[28] they accounted for 53% of the overall diagnoses and 71% among men. According to a 2010 federal study, one in five men who have sex with men are HIV positive and nearly half do not realize it.[29]

According to a CDC study, HIV prevalence in the MSM population of the U.S. varies widely by ethnicity. "As many as 46% of black MSM have HIV" while "the HIV rate is estimated at 21% for white MSM and 17% for Hispanic MSM."[30][31][32] In the United States from 2001 to 2005, the highest transmission risk behaviors were sex between men (40–49% of new cases) and high risk heterosexual sex (32–35% of new cases).[33] HIV infection is increasing at a rate of 12% annually among 13–24-year-old American men who have sex with men.[34][35][36] Experts attribute this to "AIDS fatigue" among younger people who have no memory of the worst phase of the epidemic in the 1980s and early 1990s, as well as "condom fatigue" among those who have grown tired of and disillusioned with the unrelenting safer sex message. The increase may also be because of new treatments.[34] In developing countries, HIV infection rates have been characterized as skyrocketing among MSM.[37] Studies have found that less than 5% of MSM in Africa, Asia, and Latin America have access to HIV-related health care.[37]

HIV prevention with PrEP

Main article: Pre-exposure prophylaxis for HIV prevention

Pre-exposure prophylaxis (PrEP) is the use of medication to prevent HIV transmission in people who have not yet been exposed to the virus. When used as directed, PrEP has been shown to be highly effective, reducing the risk of contracting HIV up to 99%.[38] As of 2018, numerous countries have approved the use of PrEP for HIV/AIDS prevention, including the United States, South Korea,[39] France, Norway,[40] Australia,[41] Israel,[42] Canada,[42] Kenya, South Africa, Peru, Thailand, the European Union[43][44] and Taiwan.[45] New Zealand was one of the first countries in the world to publicly fund PrEP for the prevention of HIV in March 2018.[46]

Other sexually transmitted infections

Main article: Healthcare and the LGBT community

Men who have sex with men are at a higher risk of acquiring hepatitis B and hepatitis A through unprotected sexual contact. The U.S. CDC and ACIP recommend hepatitis A and hepatitis B vaccination for men who have sex with men.[47] About a third of the world's population, more than 2 billion people, have been infected with hepatitis B virus (HBV).[48] Hepatitis B is a disease caused by HBV which infects the liver and causes an inflammation called hepatitis.

Syphilis (caused by infection with Treponema pallidum) is passed from person to person through direct contact with a syphilis sore; these occur mainly on the external genitals, or in the vagina, anus, or rectum.[49] Sores also can occur on the lips and in the mouth.[49] Transmission of the organism occurs during vaginal, anal, or oral sex.[49] In 2006, 64% of the reported cases in the United States were among men who have sex with men.[49] This is consistent with a rise in the incidence of syphilis among MSM in other developed nations, attributed by Australian and UK authors to increased rates of unprotected sex among MSM.[50][51]

Genital human papillomavirus (HPV) is a common virus that most sexually active people in the U.S. will have at some time in their lives.[52] It is passed on through genital contact and is also found on areas that condoms do not cover.[52] Most men who get HPV of any type never develop any symptoms or health problems.[52] Some types of HPV can cause genital warts, penile cancer, or anal cancer.[52] MSM and men with compromised immune systems are more likely than other men to develop anal cancer.[52] The incidence of anal cancer among HIV‐positive MSM is nine times higher than among HIV‐negative MSM, even in antiretroviral therapy. HIV-negative MSM has a higher incidence than the general population.[53] Men with HIV are also more likely to get severe cases of genital warts that are hard to treat.[52][54][55]

Though not commonly classified as an STI, giardiasis can be transmitted between gay men,[56] and it can be responsible for severe weight loss and death for individuals who have compromised immune systems, especially HIV.[57]

Mental health

Main article: Mental health in the LGBT community

According to the U.S. Centers for Disease Control, the majority of gay and bisexual men have and maintain good mental health, though research has shown that they are at greater risk for mental health problems. Stigma and homophobia can have negative consequences on health. Compared to other men, gay and bisexual men have a higher chance of having depression and anxiety disorders.[58]


Mpox has been shown to disproportionately affect men who have sex with men.[59]

MSM blood and tissue donor controversy

Main article: Blood donation restrictions on men who have sex with men

Many countries impose restrictions on donating blood for men who have or have had sex with men, as well as their female sexual partners. Similar restrictions in many countries also prohibit donation of tissues such as corneas by men who have sex with men, often with far longer deferral periods than for MSM blood donors.[60] Most national standards require direct questioning regarding a donor's sexual history, but the length of deferral varies.

Blood donation policies for men who have sex with men
  Men who have sex with men may donate blood without a deferral
  Men who have sex with men may not donate blood within the deferral period
  Men who have sex with men may not donate blood; permanent deferral
Blood donation policies for female sex partners of men who have sex with men
  Female sex partners of men who have sex with men may donate blood without a deferral
  Female sex partners of men who have sex with men may not donate blood within the deferral period
  Female sex partners of men who have sex with men may not donate blood; permanent deferral

See also


  1. ^ a b "UNAIDS: Men who have sex with men" (PDF). UNAIDS. 2006. Archived from the original (PDF) on June 21, 2013. Retrieved April 2, 2014.
  2. ^ Young RM, Meyer IH (July 2005). "The trouble with "MSM" and "WSW": erasure of the sexual-minority person in public health discourse". Am J Public Health. 95 (7): 1144–1149. doi:10.2105/AJPH.2004.046714. PMC 1449332. PMID 15961753.
  3. ^ Glick M, Muzyka BC, Salkin LM, Lurie D (May 1994). "Necrotizing ulcerative periodontitis: a marker for immune deterioration and a predictor for the diagnosis of AIDS". J. Periodontol. 65 (5): 393–7. doi:10.1902/jop.1994.65.5.393. PMID 7913962.
  4. ^ The Huffington Post, "Cleo Manago: The Most Dangerous Black Gay Man?" by Irene Monroe, January 1, 2016 [1]
  5. ^ A review of knowledge about the sexual networks and behaviors of men who have sex with men in Asia. Dowsett, Grierson and McNally.PDF Archived August 21, 2006, at the Wayback Machine
  6. ^ "MSM in Africa: highly stigmatized, vulnerable and in need of urgent HIV prevention". Archived from the original on July 13, 2007.
  7. ^ "Criminalizing high-risk groups such as MSM". Archived from the original on December 27, 2008. Retrieved July 16, 2008.((cite web)): CS1 maint: unfit URL (link)
  8. ^ Operario D, Burton J, Underhill K, Sevelius J (January 2008). "Men who have sex with transgender women: challenges to category-based HIV prevention". AIDS Behav. 12 (1): 18–26. doi:10.1007/s10461-007-9303-y. PMID 17705095. S2CID 31831055.
  9. ^ "Between Men – HIV/STI prevention for men who have sex with men" (PDF). Frontiers Prevention Project. 2003. p. 3. Retrieved May 21, 2021.
  10. ^ Mosher, William D.; Anjani Chandra; Jo Jones (September 15, 2005). "Sexual Behavior and Selected Health Measures: Men and Women 15–44 Years of Age, United States, 2002" (PDF). Advance Data from Vital and Health Statistics (362): 2. PMID 16250464. Retrieved May 7, 2012.
  11. ^ Wellings, Kaye; Mitchell, Kirstin; Collumbien, Martine (2012). Sexual Health: A Public Health Perspective. McGraw-Hill International. p. 91. ISBN 978-0-335-24481-2. Retrieved August 29, 2013.
  12. ^ Goldstone, Stephen E.; Welton, Mark L. (2004). "Anorectal Sexually Transmitted Infections in Men Who Have Sex with Men—Special Considerations for Clinicians". Clin Colon Rectal Surg. 17 (4): 235–239. doi:10.1055/s-2004-836944. PMC 2780055. PMID 20011265.
  13. ^ Edwin Clark Johnson, Toby Johnson (2008). Gay Perspective: Things Our Homosexuality Tells Us about the Nature of God & the Universe. Lethe Press. p. 139. ISBN 978-1-59021-015-4. Retrieved February 12, 2011.
  14. ^ Steven Gregory Underwood (2003). Gay Men and Anal Eroticism: Tops, Bottoms, and Versatiles. Harrington Park Press. ISBN 978-1-56023-375-6. Retrieved February 12, 2011.
  15. ^ "Sexual Behavior Does Not Explain Varying HIV Rates Among Gay And Straight Men". Medical News Today. September 13, 2007.
  16. ^ Goodreau SM, Golden MR (October 2007). "Biological and demographic causes of high HIV and sexually transmitted disease prevalence in men who have sex with men". Sex Transm Infect. 83 (6): 458–462. doi:10.1136/sti.2007.025627. PMC 2598698. PMID 17855487.
  17. ^ Mercer, Catherine H.; Prah, Philip; Field, Nigel; Tanton, Clare; Macdowall, Wendy; Clifton, Soazig; Hughes, Gwenda; Nardone, Anthony; Wellings, Kaye; Johnson, Anne M.; Sonnenberg, Pam (July 7, 2016). "The health and well-being of men who have sex with men (MSM) in Britain: Evidence from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)". BMC Public Health. 16 (1): 525. doi:10.1186/s12889-016-3149-z. ISSN 1471-2458. PMC 4936006. PMID 27386950.
  18. ^ Prah, Philip; Hickson, Ford; Bonell, Chris; McDaid, Lisa M.; Johnson, Anne M.; Wayal, Sonali; Clifton, Soazig; Sonnenberg, Pam; Nardone, Anthony; Erens, Bob; Copas, Andrew J. (September 1, 2016). "Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys". Sexually Transmitted Infections. 92 (6): 455–463. doi:10.1136/sextrans-2015-052389. ISSN 1368-4973. PMC 5013102. PMID 26965869.
  19. ^ "HIV Transmission". Centers for Disease Control and Prevention (CDC). Retrieved May 3, 2014.
  20. ^ Hoeger, Werner W. K.; Hoeger, Sharon A. (2010). Fitness and Wellness: A Personalized Program. Cengage Learning. p. 455. ISBN 978-1-133-00858-3. Retrieved May 3, 2014.
  21. ^ Remis, Robert S. (2014). "HIV Transmission among Men Who Have Sex with Men due to Condom Failure". PLOS ONE. 9 (9): 9. Bibcode:2014PLoSO...9j7540R. doi:10.1371/journal.pone.0107540. PMC 4161430. PMID 25211493.
  22. ^ Sepkowitz KA (June 2001). "AIDS—the first 20 years". N. Engl. J. Med. 344 (23): 1764–1772. doi:10.1056/NEJM200106073442306. PMID 11396444.
  23. ^ Weiss RA (May 1993). "How does HIV cause AIDS?". Science. 260 (5112): 1273–1279. Bibcode:1993Sci...260.1273W. doi:10.1126/science.8493571. PMID 8493571.
  24. ^ Cecil, Russell (1988). Textbook of Medicine. Philadelphia: Saunders. pp. 1523, 1799. ISBN 978-0-7216-1848-7.
  25. ^ a b "2009 AIDS epidemic update". Joint United Nations Programme on HIV/AIDS and World Health Organization. November 2009. Archived from the original on September 28, 2011. Retrieved September 28, 2011.
  26. ^ "Men who have sex with men (MSM) and HIV/AIDS". July 20, 2015.
  27. ^ Consumer Affairs Branch (CBER) (March 18, 2013). "Blood Donations from Men Who Have Sex with Other Men Questions and Answers". Retrieved May 17, 2013.
  28. ^ "Few Americans with HIV have virus under control". NBC News News Services. Retrieved November 30, 2011.
  29. ^ "1 in 5 men who have sex with men have HIV, nearly half don't know it". USA Today. September 23, 2011. Retrieved November 30, 2011.
  30. ^ "HIV more prevalent among black MSM despite fewer risk behaviors".
  31. ^ Millett, Gregorio A; Flores, Stephen A; Peterson, John L; Bakeman, Roger (October 2007). "Explaining disparities in HIV infection among black and white men who have sex with men: a meta-analysis of HIV risk behaviors". AIDS. 21 (15): 2083–2091. doi:10.1097/QAD.0b013e3282e9a64b. PMID 17885299. S2CID 22098986.
  32. ^ "Kaiser Daily HIV/AIDS Report Summarizes Opinion Pieces on U.S. AIDS Epidemic". Archived from the original on September 17, 2018. Retrieved May 20, 2010.
  33. ^ "2005 report". Centers for Disease Control and Prevention.
  34. ^ a b Paddock, Catharine (June 27, 2008). "HIV Rising Among Young Gay Men In The US". Medical News Today.
  35. ^ Centers for Disease Control and Prevention (CDC) (June 2008). "Trends in HIV/AIDS diagnoses among men who have sex with men—33 States, 2001–2006". MMWR Morb. Mortal. Wkly. Rep. 57 (25): 681–6. PMID 18583954.
  36. ^ "New HIV diagnoses rising in New York City among young men who have sex with men". Archived from the original on April 9, 2014.
  37. ^ a b Foley, Meraiah (July 24, 2007). "HIV rates skyrocketing among men who have sex with men". Taiwan News. Retrieved May 21, 2021.
  38. ^ "Effectiveness of Prevention Strategies to Reduce the Risk of Acquiring or Transmitting HIV". Centers for Disease Control and Prevention (CDC). November 12, 2019. Archived from the original on December 10, 2019. Retrieved December 9, 2019.
  39. ^ "Korea has just approved PrEP but who can afford it at that price?". Gay Star News. February 21, 2018. Archived from the original on January 5, 2021. Retrieved March 17, 2020.
  40. ^ "Norway becomes first country to offer free PrEP - Star Observer". October 21, 2016. Retrieved January 12, 2017.
  41. ^ "Pre-Exposure Prophylaxis (PrEP)". Australian Federation of AIDS Organizations. Retrieved December 15, 2017.
  42. ^ a b "Canada and Israel OK Truvada as PrEP to Prevent HIV". Poz. March 1, 2016. Retrieved January 12, 2017.
  43. ^ Brooks M (July 22, 2016). "Truvada Recommended as First Drug for HIV PrEP in Europe". Medscape. Retrieved December 15, 2017.
  44. ^ "First medicine for HIV pre-exposure prophylaxis recommended for approval in the EU". European Medicines Agency (EMA) (Press release). July 22, 2016. Retrieved January 12, 2017.
  45. ^ Gilead Sciences Policy Position. "Pre-Exposure Prophylaxis (PrEP) for HIV Prevention" (PDF). Gilead Sciences. Retrieved December 15, 2017.
  46. ^ "HIV prevention drug Truvada to be publicly funded in New Zealand". Retrieved February 7, 2018.
  47. ^ "Men Who Have Sex with Men | Populations and Settings | Division of Viral Hepatitis | CDC". August 21, 2019. Retrieved March 18, 2020.
  48. ^ "WHO | Hepatitis B".
  49. ^ a b c d Syphilis & MSM (Men Who Have Sex With Men) – CDC Fact Sheet Archived June 27, 2017, at the Wayback Machine, Centers for Disease Control and Prevention
  50. ^ Christopher K Fairley; Jane S Hocking; Nicholas Medland (2005). "Syphilis: back on the rise, but not unstoppable". Medical Journal of Australia. 183 (4): 172–173. doi:10.5694/j.1326-5377.2005.tb06985.x. PMID 16097910. S2CID 46196236.
  51. ^ M Hourihan; H Wheeler; R Houghton; B T Goh (2004). "Lessons from the syphilis outbreak in homosexual men in east London". Sex Transm Infect. 80 (6): 509–511. doi:10.1136/sti.2004.011023. PMC 1744940. PMID 15572625.
  52. ^ a b c d e f "STD Facts – HPV and Men". Centers for Disease Control and Prevention. Retrieved August 17, 2007.
  53. ^ Quinn, Gwendolyn P.; Sanchez, Julian A.; Sutton, Steven K.; Vadaparampil, Susan T.; Nguyen, Giang T.; Green, B. Lee; Kanetsky, Peter A.; Schabath, Matthew B. (September 1, 2015). "Cancer and lesbian, gay, bisexual, transgender/transsexual, and queer/questioning (LGBTQ) populations". CA: A Cancer Journal for Clinicians. 65 (5): 384–400. doi:10.3322/caac.21288. ISSN 1542-4863. PMC 4609168. PMID 26186412.
  54. ^ Frisch M, Smith E, Grulich A, Johansen C (2003). "Cancer in a population-based cohort of men and women in registered homosexual partnerships". Am. J. Epidemiol. 157 (11): 966–972. doi:10.1093/aje/kwg067. PMID 12777359. However, the risk for invasive anal squamous carcinoma, which is believed to be caused by certain types of sexually transmitted human papilloma viruses, notably type 16, was significantly 31-fold elevated at a crude incidence of 25.6 per 100,000 person-years.
  55. ^ Chin-Hong PV, Vittinghoff E, Cranston RD, et al. (2005). "Age-related prevalence of anal cancer precursors in homosexual men: the EXPLORE study". J. Natl. Cancer Inst. 97 (12): 896–905. doi:10.1093/jnci/dji163. PMID 15956651.
  56. ^ "Factsheet – Health Protection Surveillance Centre". Archived from the original on December 17, 2010. Retrieved May 17, 2013.
  57. ^ "Giardia in Drinking Water Giardiasis Waterborne Disease". Retrieved May 17, 2013.
  58. ^ "Mental Health for Gay and Bisexual Men | CDC". January 16, 2019. Retrieved March 17, 2020.
  59. ^ "Morbitity and Mortality Weekly Report". August 5, 2022. Retrieved March 13, 2023.
  60. ^ Puente, Michael A; Patnaik, Jennifer L; Lynch, Anne M (2020). "Association of Federal Regulations in the United States and Canada With Potential Corneal Donation by Men Who Have Sex With Men". JAMA Ophthalmol. 138 (11): 1143–1149. doi:10.1001/jamaophthalmol.2020.3630. PMC 7516798. PMID 32970105.

Further reading