Psychedelics & Birth Control Pills
By Martha Allitt
Birth control pills are the most popular form of contraception across the UK, Europe, Asia, and Oceania. Nearly 12% of all women in the UK received prescriptions for contraceptive medication in 2022. As psychedelics continue to grow in popularity worldwide, understanding how they might affect the effectiveness and side effects of these drugs is imperative.
Psychedelics and Birth Control Mechanisms
Birth control pills consist of steroid hormones, either progesterone or a combination of progesterone and estrogen. Emerging evidence suggests psychedelics interact with female reproductive hormones. However, no studies have directly looked at this interaction when it comes to birth control pills.
Progesterone-only pills reduce pregnancy risk by blocking the release of gonadotropin-releasing hormone (GnRH). This stops other key reproductive hormones from being produced, preventing ovulation. Combined pills, which include estrogen, work similarly, but estrogen additionally helps prevent the release of hormones and helps women continue having regular bleeds.
Lindsey Block, PhD, a reproductive science lecturer and research associate at Hystelica, believes that psychedelics are unlikely to directly interact with estrogen and progesterone receptors. However, she notes that there may be an overlap in their downstream biological effects.
Classical psychedelics activate 5-HT2A receptors, which respond to the chemical messenger serotonin. One study found that blocking these receptors inhibited the release of luteinising hormone-releasing hormone (LHRH) in rats. Psychedelics could therefore have an opposite effect, increasing LHRH through the activation of 5-HT2A. This would increase fertility and potentially jeopardise the effectiveness of birth control pills.
Moreover, both LSD and mescaline have been found to increase uterine contractions. These muscle movements help move sperm toward the egg for fertilisation and are also important in fertility.
Taking Cautionary Measures
If psychedelics do have the potential to decrease the effectiveness of birth control pills, it’s critical women should be informed about this risk. Extra cautionary measures, like wearing a condom, could be advised if women using psychedelics want to avoid the risk of pregnancy.
For example, St. John's Wort is a mood-enhancing herb that interacts with the serotonin system like classical psychedelics. Health officials warn against women using St. John Wort at the same time as taking birth control because it can decrease their effectiveness.
Scientists have shown that St. John’s Wort increases the action of CYP3A enzymes, which break down estrogen. There’s no direct evidence to show psychedelics also activate these enzymes, but it’s possible the shared effects of St. John’s Wort and psychedelics on serotonin receptors could influence birth control efficacy. For instance, 5-HT2A receptors are found in large quantities in the gut, which could affect how well oral contraceptives are absorbed into the bloodstream.
Could Birth Control Affect Psychedelic Effects?
Lindsey says that though “the serotonin pathway and estrogen and progesterone pathways are entwined,” it may be more likely that hormonal contraception impacts psychedelics than the reverse.
In line with this suggestion, some early psychedelic research found progesterone decreased the effects of LSD, although the evidence was limited to animals and small numbers of humans. Men who had progesterone and LSD together had less pronounced changes in their sensory-motor and cognitive functions than those who took LSD alone in one experiment.
In more recent times, researchers have found that progesterone can block the effects of DMT through its action at sigma-1 receptors. These receptors are directly affected by the intense, short-acting psychedelics DMT and 5-MeO-DMT and are thought to contribute to their psychoactive effects.
With both DMT and 5-MeO-DMT being trialled for the treatment of depression, knowing whether they interact with contraceptive medication could be hugely important. Therapists may want to consider what doses are appropriate depending on whether a woman is taking birth control pills.
Whereas these lines of evidence suggest progesterone could decrease psychedelic effects, other research suggests estrogen could amplify the signalling of 5-HT2A receptors and increase psychedelic effects.
In a study on rats, scientists found that estrogen increased the number of 5-HT2A receptors in brain areas involved in cognition and emotions. Rats with dysfunctional estrogen receptors also showed impaired 5-HT2A action in another study.
Shared Breakdown Mechanisms
Both estrogen and progesterone, as well as psychedelics, are broken down by enzymes from the CYP family. Since these drugs share the same enzymes, the availability of CYP enzymes could become limited when used together. This could prolong the action of either drug and increase the risk of side effects.
Psilocin, the active molecule of psilocybin, and estrogen are also cleared from the system through glucuronidation, meaning they could compete for the enzymes involved in this process.
Shared side effects of contraceptive pills and psychedelics include headaches, nausea, and increased blood pressure. If amplified through combined use, these side effects could become more unpleasant and potentially dangerous.
An Unmet Need for More Research
People are becoming more interested in psychedelics, whether microdosing, attending psychedelic retreats or taking these substances recreationally. Psychedelic-assisted therapy is becoming increasingly recognised as a valuable mental health treatment and may soon be therapeutically available in several countries.
Yet, despite a growing body of psychedelic research, there remains big question marks about how they affect women’s health.
This article has highlighted several findings that give rise to speculation, but the research is conflicting. Many of these studies are also conducted in animals or small numbers of human subjects, making them unreliable measures of what might be happening in women’s bodies.
Through gaining data about women’s psychedelic use, Hystelica is starting to uncover these research gaps. We are advocating for more research into psychedelics that ensures their safe and effective use among all women.