THC exposure altered sperm function and gene expression in a lab study | Research

The takeaway

In vitro THC exposure impaired sperm capacitation and altered transcript levels, suggesting cannabis use may affect male fertility through direct effects on sperm physiology.

Reproductive biologists, fertility clinicians, and men interested in how cannabis may affect fertility.

THC impaired sperm capacitation at physiologically relevant concentrations

What the researchers found

Physiologically relevant THC concentrations altered sperm capacitation (a key step for fertilization) and changed gene expression patterns in bull sperm used as a translational model for human sperm.

Why it matters

Cannabis use is highest among reproductive-age males. If THC directly affects sperm function, it has implications for male fertility that are relevant to a large population of users.

The numbers in context

Physiologically relevant THC concentrations used. Sperm capacitation was impaired. Transcript levels were altered in THC-treated sperm compared to controls.

How the study worked

In vitro study using bull sperm of known fertility as a translational model. Sperm were treated with physiologically relevant THC concentrations. Assessed capacitation, physiological parameters, and transcript levels.

What this study cannot tell us

In vitro study using bull sperm, not human. Laboratory conditions do not replicate the reproductive tract environment. Acute THC exposure may not reflect chronic cannabis use patterns. Transcript changes may not translate to functional fertility outcomes.

How to read the evidence

In vitro study with animal model. Identifies a biological mechanism but has limited translational relevance to human male fertility.

When this study was published

Published 2023.

The bigger picture

The endocannabinoid system is present throughout the male reproductive tract. This adds to growing evidence that cannabis may affect fertility, though in vitro findings with animal sperm require human confirmation.

Questions still open

Do these findings replicate in human sperm? Does chronic cannabis use produce the same capacitation changes as acute in vitro THC exposure? Are effects reversible after cannabis cessation?

Common questions

Does cannabis affect male fertility?

This lab study found THC impaired a key step in sperm function (capacitation) and changed gene expression. However, this used bull sperm in a laboratory setting. Human fertility involves many more factors, and whether cannabis use at typical levels meaningfully reduces male fertility remains an open question.

What is sperm capacitation?

Capacitation is a process sperm must undergo before they can fertilize an egg. It involves changes in the sperm membrane and motility pattern. If THC disrupts this process, it could theoretically reduce the chance of fertilization, though many other factors also determine fertility outcomes.

Read the original research

Sperm capacitation and transcripts levels are altered by in vitro THC exposure.

BMC molecular and cell biology, 24(1), 6

View on PubMed ↗Publisher’s paper ↗

Citation

Truong, Vivien B; Davis, Ola S; Gracey, Jade; Neal, Michael S; Khokhar, Jibran Y; Favetta, Laura A. (2023). Sperm capacitation and transcripts levels are altered by in vitro THC exposure.. BMC molecular and cell biology, 24(1), 6. https://doi.org/10.1186/s12860-023-00468-3