Other · 2026
Review: how salvinorin A acts on opioid receptors rather than serotonin receptors
- Original title
- Opioid Receptors in Psychedelia: Indirect Serotonergic Modulation of Direct KOR Activation by Salvinorin A.
- Authors
- Ganado M, Rubio C, Pérez-Villavicencio J, et al.
- Journal
- Biomedicines, 2026
- Molecules
- Salvinorin A, Psilocybin, LSD, Other
- Conditions
- Treatment-resistant depression, Substance use disorder, Chronic pain, Other
- Evidence grade
- Very low
- Source
- Read the original paper
The question
Do psychedelic drugs work only through serotonin, or does the body’s own opioid system also play a role? The review focuses on salvinorin A, the active compound in the plant Salvia divinorum.
What they did
The authors reviewed published research on how psychedelics interact with opioid receptors. They pulled together evidence from test-tube studies, genetically modified animals, techniques that switch specific brain circuits on and off in animals, and human brain-imaging studies. No new participants were tested and the abstract reports no pooled numbers.
What they found
Salvinorin A acts directly on the kappa opioid receptor, a brain receptor not involved in the effects of classic psychedelics like psilocybin or LSD. It engages that receptor in an unusual, lopsided way, which the authors link to rapid loss of receptor sensitivity and to strong dissociative effects, meaning a sense of detachment from the body and surroundings. The authors describe changes in communication between deep brain structures and the cortex, reduced activity in dopamine reward pathways, and disruption of large brain networks. They also argue that classic serotonin-acting psychedelics indirectly touch opioid systems, which may contribute to pain relief and mood effects, and that salvinorin A has low potential for misuse because its effects are unpleasant and not rewarding in animal studies.
The fine print
This is a review of mechanisms, not a clinical trial, so it says nothing about whether salvinorin A helps any condition in patients. Much of the evidence cited comes from cell and animal experiments, which often do not translate to people. The abstract reports no sample sizes, no search method and no quality appraisal, and the suggested uses in depression, addiction and chronic pain are proposals rather than results. This summary is based on the abstract only.
What it means
The review argues that serotonin is not the whole story for psychedelic effects, and that opioid receptor pharmacology deserves more attention. Any therapeutic promise remains theoretical and untested in patients.
Evidence grade: Very low. This is a narrative review of mechanisms that draws mainly on laboratory and animal work, with no new human data and no pooled results.
This summary is based on the study’s published abstract.