Cannabis May Harm Male Fertility Through Multiple Pathways | Research

The takeaway

A comprehensive review finds THC disrupts testosterone, sperm motility, and sperm shape through cannabinoid receptors in the testes, while CBD's long-term fertility effects remain uncertain.

Men who use cannabis and are planning families, fertility specialists, urologists, and reproductive health researchers.

What the researchers found

THC disrupts the hypothalamic-pituitary-gonadal axis, reducing luteinizing hormone and testosterone levels. Cannabinoids interact with CB1 and CB2 receptors in testes, epididymis, and sperm cells, modulating testosterone synthesis, sperm motility, morphology, and capacitation. THC impairs mitochondrial activity and causes abnormal sperm shape. CBD's reproductive impact is less studied but uncertain long-term.

Why it matters

With cannabis use rising among men of reproductive age, understanding fertility impacts is increasingly important. The evidence shows THC affects multiple steps of sperm production and function, potentially contributing to declining sperm counts observed worldwide.

The numbers in context

THC affects: luteinizing hormone levels (reduced), testosterone levels (reduced), sperm motility (impaired), sperm morphology (abnormal), mitochondrial activity (impaired), capacitation (altered). Receptors involved: CB1 and CB2 in testes, epididymis, and sperm.

How the study worked

Narrative review synthesizing experimental and clinical studies on cannabis and male reproductive function. Covers spermatogenesis, sperm function, hormonal regulation, and the endocannabinoid system's role in reproductive homeostasis.

What this study cannot tell us

Narrative review format. Many studies are preclinical. Dose-response relationships in humans unclear. Most studies examine THC; CBD and other cannabinoids less studied. Difficult to isolate cannabis effects from tobacco co-use and lifestyle factors.

How to read the evidence

Comprehensive review with consistent findings across experimental and some clinical studies, though many gaps in human dose-response data.

When this study was published

Published in 2026, synthesizing the latest evidence on cannabinoids and male reproductive health.

The bigger picture

Male fertility has been declining globally for decades, and cannabis use has increased over the same period. While cannabis isn't the sole cause, this review suggests it may be a modifiable risk factor for couples trying to conceive.

Questions still open

Are fertility effects reversible after stopping cannabis? How long before conception should men stop using? Does CBD pose the same risks as THC for fertility?

Common questions

Can cannabis affect a man's ability to have children?

Evidence suggests yes — THC reduces testosterone, impairs sperm motility and shape, and disrupts the hormonal system controlling reproduction. These effects occur through cannabinoid receptors located directly in the testes and on sperm cells.

Is CBD safer than THC for male fertility?

CBD shows anti-inflammatory and antioxidant properties that could theoretically help, but its long-term impact on reproductive function hasn't been well studied. The review notes this as an important knowledge gap.

Read the original research

Phytocannabinoids and Male Fertility: Implications of Cannabis sativa and the Endocannabinoid System in Reproductive Regulation.

Plants (Basel, Switzerland), 15(3)

View on PubMed ↗Publisher’s paper ↗

Citation

Erukainure, Ochuko L; Nambooze, Jennifer; Chukwuma, Chika I. (2026). Phytocannabinoids and Male Fertility: Implications of Cannabis sativa and the Endocannabinoid System in Reproductive Regulation.. Plants (Basel, Switzerland), 15(3). https://doi.org/10.3390/plants15030473