Can the Menstrual Cycle Affect a Female's HIV Risk?

Hormonal changes can potentially place females at higher risk for HIV

The risk of transmitting HIV is much higher from males to females than from females to males due to in large part to the vulnerability of the vagina, cervix, and (possibly) the uterus. Not only is there greater tissue surface area in the female reproductive tract (FRT) when compared to the penis, changes in biology can often make the mucosal tissues that line the FRT even more susceptible to infection.

Woman sitting on the side of the bed holding her hip
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While the mucosal membranes of the vagina are far thicker than the rectum, with around a dozen overlapping layers of epithelial tissues providing a ready barrier from infection, HIV can still gain access to the body through healthy cells. Furthermore, the cervix, which has thinner mucosal membranes than the vagina, is lined with CD4+ T-cells, the very immune cells that HIV preferentially targets.

Many things can enhance a woman's vulnerability to HIV, including bacterial vaginosis (which can alter the vaginal flora) and cervical ectopy (also known as an "immature" cervix).

But increasing evidence has also shown that hormonal changes, either naturally occurring or induced, play a key role in increasing a female's potential for HIV acquisition.

A Note on Gender and Sex Terminology

Verywell Health acknowledges that sex and gender are related concepts, but they are not the same.

  • Sex refers to biology: chromosomal makeup, hormones, and anatomy. People are most often assigned male or female at birth based on their external anatomy; some people do not fit into that sex binary and are intersex.
  • Gender describes a person's internal sense of self as a woman, man, nonbinary person, or another gender, and the associated social and cultural ideas about roles, behaviors, expressions, and characteristics.

Research studies sometimes don't use the terminology in this way. Terms that describe gender (“woman,” “man”) may be used when terms for sex (“female,” “male”) are more appropriate. To reflect our sources accurately, this article uses terms like "female," "male," "woman," and "man" as the sources use them.

The Menstrual Cycle and HIV Risk

Hormonal changes during the normal menstrual cycle can provide HIV and other sexually transmitted infections (STIs) an increased opportunity to infect.

The immune function, both innate (natural) and adaptive (acquired after a previous infection), is known to be regulated by hormones. During the menstrual cycle, the two hormones meant to optimize the conditions for fertilization and pregnancy—estradiol and progesterone—directly affect the epithelial cells, fibroblasts (cells found in connective tissues), and immune cells that line the FRT.

During the secretory phase of the menstrual cycle (which occurs between ovulation and menstruation), increased levels of these hormones may suppress immune protection throughout the FRT. This can create a window of vulnerability, during which one may be more susceptible to HIV infection.

Regardless of this window of opportunity, a person with a uterus can acquire HIV at any point during their menstrual cycle. Therefore, it's important to focus on consistent use of safer sex practices, regardless of where you may be in your menstrual cycle.

Menopause and HIV Risk

A 2015 study suggests that changes in the FRT during menopause may also contribute to an increased risk of HIV in post-menopausal females.

It is well known that the immune function of the lower genital tract quickly declines during and after menopause, with the thinning of epithelial tissues and a marked decrease in the mucosal barrier. The mucosa, known to contain a spectrum of antimicrobials, is supported by secretions from the upper FTR that provide downstream protection to the lower genital tract.

The researchers recruited 165 asymptomatic females—including postmenopausal females; pre-menopausal females not on contraceptives; and females on contraceptives—and measured HIV vulnerability by comparing cervicovaginal fluids obtained by irrigation. Using HIV-specific testing assays, they found that post-menopausal females had three times less "natural" anti-HIV activity (11% vs. 34%) than either of the other two groups.

While conclusions are limited by the study design and size, it does suggest that hormonal changes during and after menopause may place older females at increased HIV risk. As such, greater emphasis should be placed on safer sex education for older females, as well as ensuring that HIV and other STI screenings are neither avoided nor delayed.

Hormonal Contraceptives and HIV Risk

Evidence that hormonal contraceptives can increase a female's risk of HIV has been inconsistent, either by way of oral or injectable birth control drugs.

A robust meta-analysis of 12 studies—eight done in the general population and four among high-risk females—did show a moderate, overall increase in HIV risk in females using the long-acting injectable, depot medroxyprogesterone acetate (DPMA, a.k.a. Depo-Provera). For females in the general population, the risk was seen to be smaller.

The analysis, which included over 25,000 female participants, showed no tangible association between oral contraceptives and HIV risk.

While the data is considered insufficient to suggest the termination of DPMA usage, the researchers advise that females using progestin-only injectables be informed about the uncertainty regarding DPMA and HIV risk, and that they be encouraged to use condoms and explore other preventive strategies such as HIV pre-exposure prophylaxis (PrEP).

Emerging research suggests that a female's risk of acquiring HIV is largely similar among non-condom contraceptives. That said, it's still recommended that you use condoms, regardless of any other contraceptives you may be using.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Mirmonsef P, Krass L, Landay A, Spear GT. The role of bacterial vaginosis and trichomonas in HIV transmission across the female genital tract. Curr HIV Res. 2012;10(3):202-10. doi:10.2174/157016212800618165

  2. Wira CR, Rodriguez-Garcia M, Patel MV. The role of sex hormones in immune protection of the female reproductive tractNat Rev Immunol. 2015;15(4):217-230. doi:10.1038/nri3819

  3. Byrareddy SN. Immune landscape of female reproductive tract and HIV susceptibility. EBioMedicine. 2021;70:103497. doi:10.1016/j.ebiom.2021.103497

  4. Chappell CA, Isaacs CE, Xu W, Meyn LA, Uranker K, Dezzutti CS, Moncla BJ, Hillier SL. The effect of menopause on the innate antiviral activity of cervicovaginal lavage. Am J Obstet Gynecol. 2015;213(2):204.e1-6. doi:10.1016/j.ajog.2015.03.045

  5. Ralph LJ, McCoy SI, Shiu K, Padian NS. Hormonal contraceptive use and women’s risk of HIV acquisition: a meta-analysis of observational studiesLancet Infectious Diseases. 2015;15(2):181-189. doi:10.1016/S1473-3099(14)71052-7

  6. Aberg JA, Cespedes MS. HIV and women. UpToDate.

Additional Reading

By James Myhre & Dennis Sifris, MD
Dennis Sifris, MD, is an HIV specialist and Medical Director of LifeSense Disease Management. James Myhre is an American journalist and HIV educator.