Cannabis combined with anabolic steroid nandrolone produced greater neurotoxicity than either drug alone in adolescent rats | Research

The takeaway

Combining cannabis and nandrolone in adolescent male rats caused worse cognitive deficits, more anxiety, aggression, and greater brain damage than either substance alone, driven by oxidative stress, inflammation, and cell death.

Sports medicine professionals, harm reduction advocates, researchers studying polydrug use

Combined cannabis + nandrolone: greater neurotoxicity than either drug alone

What the researchers found

Combined cannabis + nandrolone caused learning/spatial memory deficits, hypo-locomotion, anxiety, and aggression. Severe damage to hippocampal and prefrontal cortex architecture with decreased BDNF. Combined treatment increased oxidative stress, inflammatory cytokines, and activated both intrinsic and extrinsic apoptotic pathways beyond either drug alone.

Why it matters

Nandrolone (an anabolic steroid) and cannabis are commonly co-used, particularly among young males. Understanding that the combination amplifies neurotoxicity has direct harm reduction implications.

The numbers in context

Nandrolone 15 mg/kg + cannabis 20 mg/kg daily for 1 month. Combined treatment: increased MDA and NO, decreased glutathione, elevated TNF-alpha and IL-1-beta, upregulated caspases 3, 8, 9 and cytochrome c in hippocampus and PFC.

How the study worked

Adolescent male rats received nandrolone (15 mg/kg) and/or cannabis extract (20 mg/kg) daily for 1 month. Assessed: Morris water maze, open field, elevated plus maze, defensive aggression test. Brain biochemistry: BDNF, oxidative stress markers, cytokines, caspases.

What this study cannot tell us

Animal model with relatively high doses; cannabis extract composition may differ from human use; only male rats studied; 1-month treatment with immediate testing does not capture long-term or recovery effects.

How to read the evidence

Single animal study with comprehensive biochemical profiling but relatively high doses.

When this study was published

Published in 2020.

The bigger picture

Polydrug use in adolescence is common, and the synergistic neurotoxicity of cannabis + anabolic steroids adds to growing evidence that combinations can be far more damaging than individual substances.

Questions still open

Would lower doses still produce synergistic effects? Do these findings translate to the doses typically used by human adolescents who combine these substances?

Common questions

Is combining cannabis with anabolic steroids dangerous?

This animal study found the combination produced significantly worse brain damage, cognitive deficits, and behavioral problems than either substance alone. Oxidative stress, inflammation, and cell death pathways were all amplified by the combination.

Why would people use both together?

Anabolic steroid use and cannabis use both peak in adolescence and young adulthood, particularly among males. Some users may combine them without awareness that the combination could amplify neurotoxic effects.

Read the original research

Combined neurotoxic effects of cannabis and nandrolone decanoate in adolescent male rats.

Neurotoxicology, 76, 114-125

View on PubMed ↗Publisher’s paper ↗

Citation

El-Shamarka, Marwa El-Sayed; Sayed, Rabab H; Assaf, Naglaa; Zeidan, Hala M; Hashish, Adel F. (2020). Combined neurotoxic effects of cannabis and nandrolone decanoate in adolescent male rats.. Neurotoxicology, 76, 114-125. https://doi.org/10.1016/j.neuro.2019.11.001