MDMA and methamphetamine tested for effects on blood endocannabinoid levels in healthy adults

The question

Do single doses of MDMA or methamphetamine change the levels of endocannabinoids — natural signalling molecules in the body that act on the same receptors as cannabis — circulating in the blood?

What they did

Twenty-two healthy adults each attended three separate sessions. In random order and without knowing which was which, they received methamphetamine (20 mg), MDMA (100 mg), or a placebo. Blood was drawn between 150 and 180 minutes after dosing to measure two endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and participants rated the drug’s subjective effects at regular intervals.

What they found

Methamphetamine was linked to significantly lower 2-AG levels in the blood compared with placebo. MDMA did not change 2-AG levels. Neither drug changed anandamide levels. In the placebo session only, higher anandamide levels were correlated with people reporting that they disliked the ‘drug effects’, which the authors suggest may reflect expectations about how a drug will feel.

The fine print

This was a small study of 22 healthy adults, so the findings need replication. Blood was sampled only once, in a narrow window after dosing, so earlier or later changes would have been missed. Endocannabinoid levels in blood are a laboratory marker, not a measure of health, mood or addiction outcomes. This summary is based on the abstract alone.

What it means

In healthy volunteers, a single dose of MDMA did not appear to shift blood endocannabinoid levels, while methamphetamine lowered one of them. The work is early-stage biology, not evidence about treatment.

Evidence grade: Moderate. A double-blind placebo-controlled crossover trial, but with only 22 healthy participants, a single blood-sampling window, and a biological marker rather than a health outcome.

This summary is based on the study’s published abstract.