Mice given CBD daily from weaning showed fewer Sertoli cells and lower sperm viability and morphology after 34 days of treatment.
Reproductive health researchers, parents considering CBD for adolescents
Both CBD doses reduced viable and morphologically normal sperm in developing mice
What the researchers 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.
Why it matters
CBD products are increasingly accessible to younger populations, and this study suggests exposure during reproductive development could affect fertility.
The numbers in context
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 the study worked
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.
What this study cannot 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.
How to read the evidence
Controlled animal study with clear design but limited to one mouse strain and one exposure window; human relevance is uncertain.
When this study was published
Published 2025
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.
Questions still open
- 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?
Common questions
What happened to sperm quality?
Were Leydig cells affected?
Read the original research
Post-weaning exposure to cannabidiol disrupts testicular cytoarchitecture and sperm quality in mice.
Reproductive toxicology (Elmsford, N.Y.), 135, 108952
Citation
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
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