Pregnancy hormones likely alter how the body processes THC
Pregnancy hormones induce the liver enzymes that metabolize THC (CYP2C9 and CYP3A4), potentially changing how THC and its psychoactive metabolite 11-OH-THC are processed, with unknown effects on maternal and fetal safety.
Quick Facts
What This Study Found
THC is primarily (>70%) cleared by CYP2C9 to its psychoactive metabolite 11-OH-THC, with CYP3A4 contributing <30%. Both enzymes are induced during pregnancy by pregnancy hormones, which is predicted to alter THC and 11-OH-THC disposition and pharmacodynamic effects.
Key Numbers
THC clearance: >70% via CYP2C9 (to 11-OH-THC), <30% via CYP3A4. Both enzymes are induced during pregnancy.
How They Did This
Narrative review of literature on THC metabolism, pharmacokinetics, and how pregnancy-related physiological and hormonal changes may alter cannabinoid disposition.
Why This Research Matters
Cannabis is the most widely used drug of abuse during pregnancy, yet almost nothing is known about how pregnancy changes THC processing. If CYP2C9 induction increases 11-OH-THC production, pregnant users might experience stronger psychoactive effects than expected.
The Bigger Picture
Most cannabis safety discussions focus on whether THC reaches the fetus, but this review raises a different concern: pregnancy may change how THC is metabolized in the mother, potentially increasing levels of the active metabolite. This adds another layer of uncertainty to prenatal cannabis use.
What This Study Doesn't Tell Us
Predictions based on known enzyme induction patterns, not direct measurement of THC pharmacokinetics in pregnant women. In vitro enzyme studies may not fully predict in vivo changes. Individual genetic variation in CYP2C9 adds further complexity.
Questions This Raises
- ?Do pregnant cannabis users experience different psychoactive effects due to altered metabolism?
- ?Does increased 11-OH-THC production affect fetal exposure?
Trust & Context
- Key Stat:
- >70% of THC cleared by pregnancy-induced CYP2C9
- Evidence Grade:
- Thorough review of pharmacokinetic principles with predicted but not directly measured effects of pregnancy on THC disposition.
- Study Age:
- 2024 review of THC pharmacokinetics and pregnancy physiology
- Original Title:
- The impact of pregnancy and associated hormones on the pharmacokinetics of Δ9-tetrahydrocannabinol.
- Published In:
- Expert opinion on drug metabolism & toxicology, 20(1-2), 73-93 (2024)
- Authors:
- Authement, Aurora K, Isoherranen, Nina(2)
- Database ID:
- RTHC-05097
Evidence Hierarchy
Frequently Asked Questions
Does pregnancy change how the body processes THC?
Likely yes. The liver enzymes that break down THC (CYP2C9 and CYP3A4) are induced during pregnancy, which is predicted to change how quickly THC is processed and how much of its active metabolite is produced.
Could this make THC effects stronger during pregnancy?
It is possible. If CYP2C9 induction increases production of 11-OH-THC (which is also psychoactive), the effects could differ from what non-pregnant users experience, though this has not been directly measured.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-05097APA
Authement, Aurora K; Isoherranen, Nina. (2024). The impact of pregnancy and associated hormones on the pharmacokinetics of Δ9-tetrahydrocannabinol.. Expert opinion on drug metabolism & toxicology, 20(1-2), 73-93. https://doi.org/10.1080/17425255.2024.2309213
MLA
Authement, Aurora K, et al. "The impact of pregnancy and associated hormones on the pharmacokinetics of Δ9-tetrahydrocannabinol.." Expert opinion on drug metabolism & toxicology, 2024. https://doi.org/10.1080/17425255.2024.2309213
RethinkTHC
RethinkTHC Research Database. "The impact of pregnancy and associated hormones on the pharm..." RTHC-05097. Retrieved from https://rethinkthc.com/research/authement-2024-the-impact-of-pregnancy
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.