Daily CBD exposure during development reduced sperm quality in young mice

Mice given CBD daily from weaning showed fewer Sertoli cells and lower sperm viability and morphology after 34 days of treatment.

Carvalho, Renata K et al.·Reproductive toxicology (Elmsford·2025·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-06165Animal StudyPreliminary Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Both CBD doses (15 and 30 mg/kg/day) reduced Sertoli cell numbers at multiple spermatogenesis stages, decreased viable sperm percentage, and reduced morphologically normal sperm.

Key Numbers

Both doses reduced Sertoli cells at stages VII-VIII, IX, and XII; CBD 15 mg/kg group showed decreased PCNA-positive spermatocytes at stages VII-VIII; both doses reduced viable and morphologically normal sperm percentages.

How They Did This

Male Swiss mice received intragastric CBD (15 or 30 mg/kg/day) or sunflower oil control for 34 consecutive days starting at postnatal day 21; testicular tissue and sperm were analyzed.

Why This Research Matters

CBD products are increasingly accessible to younger populations, and this study suggests exposure during reproductive development could affect fertility.

The Bigger Picture

As CBD becomes widely available in supplements and wellness products, understanding its effects on developing reproductive systems is an emerging research priority.

What This Study Doesn't Tell Us

Animal study using mouse model; CBD doses may not directly translate to human exposures; only examined one 34-day exposure window; did not assess fertility outcomes directly.

Questions This Raises

  • ?Would these effects reverse after stopping CBD?
  • ?Do similar changes occur in human males exposed during puberty?
  • ?What CBD dose thresholds exist for reproductive safety?

Trust & Context

Key Stat:
Both CBD doses reduced viable and morphologically normal sperm in developing mice
Evidence Grade:
Controlled animal study with clear design but limited to one mouse strain and one exposure window; human relevance is uncertain.
Study Age:
Published 2025
Original Title:
Post-weaning exposure to cannabidiol disrupts testicular cytoarchitecture and sperm quality in mice.
Published In:
Reproductive toxicology (Elmsford, N.Y.), 135, 108952 (2025)
Database ID:
RTHC-06165

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

What happened to sperm quality?

Both CBD doses reduced the percentage of viable sperm and the percentage of morphologically normal sperm compared to controls.

Were Leydig cells affected?

No. Leydig cell nuclear diameter, volume, and proliferation markers showed no significant differences between CBD and control groups.

Read More on RethinkTHC

Cite This Study

RTHC-06165·https://rethinkthc.com/research/RTHC-06165

APA

Carvalho, Renata K; Souza, Maingredy R; Nishimura, Akemy N; Silva, Edvaldo M; Silva, Cinthia R B; Guimarães, Francisco S; Andersen, Monica L; Sabóia-Morais, Simone M T; Mazaro-Costa, Renata. (2025). Post-weaning exposure to cannabidiol disrupts testicular cytoarchitecture and sperm quality in mice.. Reproductive toxicology (Elmsford, N.Y.), 135, 108952. https://doi.org/10.1016/j.reprotox.2025.108952

MLA

Carvalho, Renata K, et al. "Post-weaning exposure to cannabidiol disrupts testicular cytoarchitecture and sperm quality in mice.." Reproductive toxicology (Elmsford, 2025. https://doi.org/10.1016/j.reprotox.2025.108952

RethinkTHC

RethinkTHC Research Database. "Post-weaning exposure to cannabidiol disrupts testicular cyt..." RTHC-06165. Retrieved from https://rethinkthc.com/research/carvalho-2025-postweaning-exposure-to-cannabidiol

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.