1. Your cycle
  2. Sex
  3. Sexual health

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Sex and Your Menstrual Cycle: Are They Connected?

How does becoming sexually active affect your monthly cycle? Today, Flo answers this and many more fascinating questions about sex and your menstrual cycle.

Medical experts associate changes in sex drive with changes in the ratio of estrogen and progesterone, hormones that are produced by the ovaries. These shifts occur at different phases of your monthly cycle. During your period and for a few days after, the concentration of both hormones is low, resulting in less sexual desire.

By the time ovulation rolls around, estrogen peaks, naturally increasing libido. Once the process of ovulation wraps up, there’s a boost in progesterone production, and you might notice a dip in your sex drive.

The exact length of a menstrual cycle differs a lot from person to person. But how does the frequency of sexual intercourse affect it?

In an attempt to answer this question, researchers conducted a number of studies in the United States in the 1970s. They involved people who engaged in varying levels of sexual activity, didn’t use hormonal contraceptives or intrauterine devices, and started their period at least seven years before the study.

For the participants who had regular intercourse, their menstrual cycles ranged from 26 to 33 days long (with 29.5 days being the average). This length of time is considered conducive to conception since such cycles are usually ovulatory, meaning that ovulation has likely taken place.

For participants who had intercourse on an inconsistent basis, their cycles had a broader spectrum of lengths. They had either very short or very long cycles, usually anovulatory (meaning that ovulation has not taken place), compared to the other group.

After becoming sexually active, some people notice a change in their monthly cycle. Indeed, intercourse can trigger certain changes in the female body. Orgasms release large amounts of oxytocin. And even though you don’t need to orgasm to become pregnant, it produces hormonal fluctuations and reduces stress.

Routine sexual activity also tends to change certain hormone-based characteristics of your menstrual cycle. Your periods may become increasingly predictable, and symptoms of premenstrual syndrome may be less noticeable.

Huynh, Hieu Kim, et al. “Female Orgasm but Not Male Ejaculation Activates the Pituitary. A PET-Neuro-Imaging Study.” NeuroImage, U.S. National Library of Medicine, 1 Aug. 2013, www.ncbi.nlm.nih.gov/pubmed/23523775.

Caruso, Salvatore, et al. “Do Hormones Influence Women’s Sex? Sexual Activity over the Menstrual Cycle.” The Journal of Sexual Medicine, The Journal of Sexual Medicine, Jan. 2014, www.jsm.jsexmed.org/article/S1743-6095(15)30527-0/pdf.

Lorenz, Tierney K., et al. “Partnered Sexual Activity Moderates Menstrual Cycle–Related Changes in Inflammation Markers in Healthy Women: an Exploratory Observational Study.” Fertility and Sterility, American Society for Reproductive Medicine, Mar. 2017, www.fertstert.org/article/S0015-0282(16)63008-X/fulltext.

Lorenz, Tierney K, et al. “Interaction of Menstrual Cycle Phase and Sexual Activity Predicts Mucosal and Systemic Humoral Immunity in Healthy Women.” Physiology & Behavior, U.S. National Library of Medicine, 1 Dec. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4633338/.

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