CBD Improved Antioxidant Status in Rats Over 90 Days, While CBG Caused Liver Damage and Oxidative Stress | Research

The takeaway

In a 90-day rat study, low-dose CBD improved blood and liver antioxidant status with no adverse effects, while CBG at similar doses caused oxidative stress, liver damage, and blood cell abnormalities.

CBG consumers, CBD/CBG product manufacturers, toxicologists, supplement regulators.

CBD improved antioxidant status; CBG caused liver damage at the same dose

What the researchers found

CBD (0.66 mg/kg/day for 90 days) produced no changes in blood counts or biochemistry and improved redox status in blood plasma and liver, reducing malondialdehyde and carbonylated proteins. CBG (0.66-1.33 mg/kg/day) increased total oxidative stress, malondialdehyde, and carbonylated proteins, and caused hepatotoxic changes, disrupted white cell counts, and altered ALT, creatinine, and calcium. Both accumulated in tissues at low ng/g levels.

Why it matters

CBG is increasingly marketed alongside CBD as a beneficial cannabinoid, but this study shows dramatically different safety profiles. While CBD improved antioxidant status, CBG caused oxidative damage and liver toxicity at comparable doses. This is a critical safety distinction as CBG products proliferate.

The numbers in context

CBD: 0.66 mg/kg/day, no adverse effects, improved redox markers. CBG: 0.66-1.33 mg/kg/day, increased oxidative stress, hepatotoxic changes, disrupted white cells, altered ALT/creatinine/calcium. Both accumulated at low ng/g in liver, brain, muscle, heart, kidney, skin.

How the study worked

90-day orogastric administration in rats. CBD at 0.66 mg/kg/day, CBG at 0.66/1.33 mg/kg/day. Assessed blood counts, biochemistry, GI and liver histology, oxidative stress markers, and tissue distribution by LC-MS.

What this study cannot tell us

Animal study at specific doses that may not reflect human supplementation levels. 90-day duration may not capture longer-term effects. Only two dose levels of CBG tested. Rat metabolism of cannabinoids differs from humans.

How to read the evidence

90-day controlled animal study with comprehensive safety assessment, providing important safety data requiring human confirmation.

When this study was published

Published 2023.

The bigger picture

The authors attribute the toxicity difference to CBG's extra dimethyloctadienyl structural pattern, which is absent in CBD. This structural difference may explain the redox disruption. As minor cannabinoids like CBG gain popularity, this study is an important safety signal.

Questions still open

Are current CBG supplement doses safe for human consumption?
Should CBG products carry safety warnings based on this hepatotoxicity data?

Common questions

Is CBG as safe as CBD?

This 90-day rat study found CBD improved antioxidant status with no adverse effects, while CBG at comparable doses caused liver damage, oxidative stress, and blood abnormalities. Their safety profiles appear very different.

Does CBD have antioxidant effects?

Yes. In this study, 90 days of CBD reduced markers of oxidative damage (malondialdehyde, carbonylated proteins) in blood and liver, suggesting genuine antioxidant activity in vivo.

Read the original research

Safety assessment and redox status in rats after chronic exposure to cannabidiol and cannabigerol.

Toxicology, 488, 153460

View on PubMed ↗Publisher’s paper ↗

Citation

Polanska, Hana Holcova; Petrlakova, Katerina; Papouskova, Barbora; Hendrych, Michal; Samadian, Amir; Storch, Jan; Babula, Petr; Masarik, Michal; Vacek, Jan. (2023). Safety assessment and redox status in rats after chronic exposure to cannabidiol and cannabigerol.. Toxicology, 488, 153460. https://doi.org/10.1016/j.tox.2023.153460