18 Aug Can marijuana affect your menstrual cycle?
- Key findings: Research shows that recreational and medical marijuana use can shorten your menstrual cycle and block or delay ovulation.
UPDATED AUGUST 18, 2021 (originally published December 24, 2019)—Do you use marijuana and wonder how it can impact your hormones or menstrual cycle?
Scientists now want to know, too.1 That’s because marijuana use has become far more common and acceptable in many areas of the world today. One reason is that many people now use it to treat medical conditions, such as epilepsy, severe nausea and severe pain.2 A 2021 study from Canada’s Dalhousie University shows that some women challenged by premenstrual dysphoric disorder (PMDD)–a severe form of premenstrual syndrome that interferes with everyday life–turn to marijuana as a coping mechanism to deal with depression during their premenstrual phase.3 And more countries and states are legalizing the plant for recreational and/or medical use, making it easier to access.
Unfortunately, despite marijuana’s growing widespread use, research has not kept up with the times. There aren’t a lot of recent studies that examine its impact on female reproduction.
However, one 2018 study and one review of older research suggest that, in fact, marijuana can impact hormones and your menstrual cycle—and knowing how is important for your health and fertility. Here’s what the researchers found…
Pot can shorten your luteal phase
According to a 2018 study of 52 women in the Journal of Addiction Medicine, compared to women who smoke cigarettes only, women who smoke both marijuana and cigarettes are more likely to have a short luteal phase.4 This is the second “half” of your cycle, which starts the day after ovulation and lasts through the day before your next period. Specifically, the study found that the luteal phase of marijuana users was nearly five-and-half days shorter than non-users.
While it would have been helpful to include a group of women who didn’t smoke cigarettes at all, the results of this study suggest that components in marijuana disrupt menstrual cycle processes in ways that tobacco smokers don’t experience.
Pot can block or delay ovulation
There are some studies about marijuana and its effect on women’s reproductive systems that date back a few decades. One researcher, Lisa K. Brents, Ph.D., reviewed this research in a 2016 issue of the Yale Journal of Biology and Medicine.5
What she discovered? Regular marijuana users have a “slightly elevated rate” of menstrual cycles where you don’t ovulate (which are called anovulatory cycles) and “are also at higher risk for decreased fertility due to ovulatory abnormalities”.
The research she examined also showed that marijuana users could have a longer follicular phase “resulting in delayed ovulation” and “have a luteal phase shorter than 11 days”, which is considered shorter than what is typical—the same results that are echoed by the 2018 study above.
How does marijuana disrupt your menstrual cycle?
Brents’ review of past research goes on to uncover why marijuana can alter your cycle—and, according to the studies she examined, one key culprit is the way THC (tetrahydrocannabinol), the compound that gives marijuana its euphoric sensation, disrupts the domino effect of processes that manage ovulation, specifically the hypothalamic-pituitary-ovarian axis, which regulates female reproduction. Brent writes:
“THC suppresses the release of gonadotropin-releasing hormone (GnRH) and thyrotropin-releasing hormone (TRH) from the hypothalamus, preventing these hormones from stimulating the release of prolactin and the gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), from the anterior pituitary. The gonadotropins maintain the menstrual cycle by promoting ovarian follicle maturation, stimulating production of the ovarian steroids estradiol and progesterone, and inducing ovulation, and alterations in circulating gonadotropin can disrupt these processes.”
The risks of wonky cycles
When you don’t ovulate in your cycle, your body doesn’t produce typical amounts of estrogen or progesterone. This can result in changes in menstrual flow, such as heavy bleeding, no bleeding or irregular bleeding. And, it has the potential to raise your risk of health issues later in life since a certain level of estrogen in your premenopausal (cycling) years helps protect your bones, heart and brain.
Additionally, when you don’t ovulate when you expect to in your cycle because it’s delayed or absent, this will also impact fertility—whether you want to get pregnant or are trying to be accurate when avoiding pregnancy.
Unfortunately, research about marijuana and menstrual cycles is still evolving and more studies need to be conducted. So, this is a good time to become an active member of your own healthcare team: If you use marijuana in any form, consider tracking your menstrual cycle (which means making daily notes about your flow, cervical mucus, health, moods, energy and more). And use an ovulation tool (such as a basal thermometer and urine strips that measure luteinizing hormone available at drugstores and Amazon) to determine if you’ve ovulated and when.
And to figure out if marijuana is having an impact on your cycle, take a break from using the drug for one to three months (with the okay from your doctor if you’re using it medicinally) and continue tracking your cycle to see if you notice any changes.
I’ve made it easy to track your cycle with my Hormonology Menstrual Cycle Tracker Journal, which is a paperback period tracker that’s available at Amazon. It gives you 12 sets (a year’s worth) of period tracking calendars that help you easily monitor more than 70 facets of your cycle, such as flow, basal temperature, mood and energy. It’s also fully customizable so you can add your own categories.
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(1) Bryn Nelson, David B. Kaminsky, “New momentum in exploring marijuana’s medical benefits,” Cancer Cytopathology, August 5, 2021
(2) Salomeh Keyhani, et al., “Risks and Benefits of Marijuana Use: A National Survey of U.S. Adults”, Annals of Internal Medicine, 169 (2018): 282-290
(3) Kayla M. Joyce, et al., “The impact of depressed mood and coping motives on cannabis use quantity across the menstrual cycle in those with and without pre-menstrual dysphoric disorder”, Addiction, published online March, 2, 2021
(4) Sara Lammert, et al., “Menstrual Cycle in Women Who Co-use Marijuana and Tobacco,” Journal of Addiction Medicine, 12 (2018): 207-211
(5) Lisa K. Brents, “Marijuana, the Endocannabinoid System and the Female Reproductive System,” The Yale Journal of Biology and Medicine, 89 (2016): 175-191
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