Can CBD help with birth control, and if so, how?
There are several ways by which CBD may interfere with the effectiveness of birth control methods, primarily hormonal ones.
CBD has been shown to compete with estradiol, influence hormones, and interfere with how contraceptives are broken down in the body.
CBD Competes with Estradiol
Estradiol is one of three estrogen hormones naturally produced in the body. Increased estradiol levels precede the maturation and release of the egg from the ovary and the thickening of the uterus lining to implant a fertilized egg(1).
A study published in The Journal of Pharmacology and Experimental Therapeutics examined CBD’s interference with estrogen receptors in rats (2). At large doses, cannabis exhibited neither estrogenic or non-estrogenic effects.
Of several other common cannabinoids tested, only cannabidiol competed with estradiol for estrogen receptor binding. This binding action was evident only at very high concentrations of cannabidiol.
The study found that CBD might compete with estradiol for estrogen receptors found in the female reproductive system.
Scientists believe this action is how CBD prevents estrogen-based contraceptives from working properly, possibly leading to an increased risk of unwanted pregnancy.
CBD Influences Sex Hormones
Hormonal contraceptives work by influencing hormone behavior. In a study published in 2019 in the International Journal of Reproductive Medicine, it was noted that the essential component for any hormonal contraceptive method is progestogen(3).
Progestogens are synthetic forms of progesterone, a naturally occurring sex hormone. Progestogen’s primary role is to prevent ovulation through a negative feedback mechanism, resulting in a decrease in luteinizing hormone.
Luteinizing hormone is associated with reproduction and ovulation. Its stimulation of either ovary or testicles results in the release of an egg from the ovary (ovulation) in women or testosterone production in men(4).
A study found that carefully-controlled regulation of the endocannabinoid system (ECS) is required for successful reproduction, and marijuana from the Cannabis sativa plants may disrupt the delicate balance of the ECS in the female reproductive system (5).
A study published in the Journal of Ovarian Research in 2019 examined the role of the endocannabinoid system in female reproductive tissues(6).
The authors found that chronic exposure to cannabinoids resulted in reduced sperm count, serum testosterone levels, and reduced ovulation in women(5).
In females, chronic exposure to cannabinoids delayed sexual maturation, caused menstrual cycle disruption, and reduced serum concentrations of sex hormones.
CBD Interferes with Metabolism of Contraceptives
Preclinical research shows that CBD is broken down by cytochrome P450 enzymes while functioning as a competitive inhibitor of the same liver enzymes(7).
The cytochrome P450 enzyme system is responsible for breaking down over 60% percent of any drugs, including contraceptives(8).
CBD can inhibit the cytochrome P450 system’s ability to metabolize certain drugs, leading to an overall increase in processing times(9).
When hormone-based contraceptives are taken with CBD, CBD can decrease how quickly the liver breaks down these oral contraceptives, which theoretically would increase the contraceptive hormone levels and increase the contraceptive’s effectiveness. However, unwanted side effects may occur as a result.
This enzyme-inhibiting action of CBD is suspected to increase breakthrough bleeding due to excess estrogen levels as a result of a slower breakdown. The role of marijuana or CBD on the effectiveness of oral contraceptives is unknown. Furthermore, marijuana is known to have adverse effects on fertility for both men and women. In women, it lowers the rate of ovulation which would lower pregnancy rates.
Further research is needed to determine what level of CBD impacts estrogen. Currently, there is no guideline as to the safe levels of CBD for women on birth control.
Before deciding to use CBD as a supplemental birth control method, consult with a doctor, preferably an obstetrician-gynecologist, who is experienced in cannabis use.
- Hormone Health Network. (2017, June). Estradiol. Retrieved from https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/estradiol.
- Sauer MA, Rifka SM, Hawks RL, Cutler GB Jr, Loriaux DL. Marijuana: interaction with the estrogen receptor. J Pharmacol Exp Ther. 1983;224(2):404–407.
- De Castro Coelho F, Barros C. The Potential of Hormonal Contraception to Influence Female Sexuality. Int J Reprod Med. 2019;2019:9701384. Published 2019 Mar 3. DOI:10.1155/2019/9701384.
- AACC. (2019, Dec. 5). Luteinizing Hormone. Retrieved from https://labtestsonline.org/tests/luteinizing-hormone-lh.
- Brents, Lisa. (2016). Marijuana, the Endocannabinoid System and the Female Reproductive System. The Yale Journal of Biology and Medicine. 89. 175-191.
- Walker, O.S., Holloway, A.C. & Raha, S. The role of the endocannabinoid system in female reproductive tissues. J Ovarian Res 12, 3 (2019). https://doi.org/10.1186/s13048-018-0478-9
- Jiang R, Yamaori S, Takeda S, Yamamoto I, Watanabe K. Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes. Life Sci. 2011;89(5-6):165–170. DOI:10.1016/j.lfs.2011.05.018.
- Zendulka O, Dovrtělová G, Nosková K, et al. Cannabinoids and Cytochrome P450 Interactions. Curr Drug Metab. 2016;17(3):206–226. DOI:10.2174/1389200217666151210142051;Back DJ, Orme ML. Pharmacokinetic drug interactions with oral contraceptives. Clin Pharmacokinet. 1990;18(6):472–484. DOI:10.2165/00003088-199018060-00004.
- Pharmotech SA. CBD Drug Interactions. Retrieved from https://pharmotech.ch/cbd-drug-interactions/.
- Zylenko S. (2017, June 22). Cannabis and Birth Control: What You Need to Know. Retrieved from https://naturalhealthservices.ca/cannabis-and-birth-control-what-you-need-to-know/#.