data + articles · 3 listed
newest 2020spec sheet8 rows
SR-17018 is an experimental synthetic opioid; a G-protein-biased partial agonist of the mu-opioid receptor studied for pain relief and opioid withdrawal, not approved for human medical use.
- Potent analgesia in animal pain models
- G-protein-biased signaling that, in some studies, widened the gap between pain relief and respiratory depression versus morphine or fentanyl
- Reversed established morphine tolerance and suppressed withdrawal signs in preclinical models
- Studied as a possible tool for opioid maintenance or tapering research
- As a mu-opioid agonist it can still cause life-threatening respiratory depression and overdose
Overview
One of the "biased opioid" research compounds; the pitch is analgesia with less tolerance and breathing suppression, but that safety story is still contested in animals and there is zero human data. It has drifted into the grey research-chemical market, which is where the real risk is.
Mechanism
SR-17018 binds the mu-opioid receptor (MOR) and acts as a biased partial ; it preferentially drives G-protein (Gi/o) signaling while recruiting comparatively little beta-arrestin-2. The idea behind biased agonism is that G-protein signaling carries the analgesia while beta-arrestin recruitment is linked to tolerance, constipation, and respiratory depression, so a G-protein-biased might separate pain relief from the worst opioid harms. In preclinical work SR-17018 also reversed established morphine tolerance and suppressed withdrawal, which is why it was explored as a maintenance or tapering tool.
receptor fingerprint
Beta-arrestin-2 recruitmentModulator
Mu-opioid receptor (MOR)Partial Agonist
Safetyrisks and cautions, not medical advice
There are no human clinical trials, so its safety in people is unknown. Animal findings are mixed; some studies reported a wider window between analgesia and respiratory depression than morphine or fentanyl, while others (and the low intrinsic efficacy re-analysis) argue the improvement is modest and route-dependent, with oral dosing looking less favorable. It still produces physical dependence and withdrawal in animal models, so it is not "non-addictive." The bigger practical danger is that it is sold as an unregulated research chemical with no quality control; mislabeling, wrong dosing, and contamination are real risks, and as an opioid it can still stop breathing. Treat any non-clinical use as high-risk.
Subjective profileweighing the evidence above
Treat it as an opioid, because that is what it is. The bias story is contested, the respiratory safety margin looks modest and route-dependent, it still causes dependence and withdrawal in animals, and no human trial has ever been run. Sold unregulated, it is a potent opioid of unknown strength.
Resources
No suppliers are provided for compounds like this. This entry is here for reference.
Research
- 2017first citedBias Factor and Therapeutic Window Correlate to Predict Safer Opioid Analgesics
- 2020most recentA G protein signaling-biased agonist at the μ-opioid receptor reverses morphine tolerance while…
- 1.Bias Factor and Therapeutic Window Correlate to Predict Safer Opioid Analgesics
- 2.A G protein signaling-biased agonist at the μ-opioid receptor reverses morphine tolerance while preventing morphine withdrawal.
- 3.Low intrinsic efficacy for G protein activation can explain the improved side effect profiles of new opioid agonists
3 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
FAQ
What is SR-17018 used for?
It is a research compound studied for pain relief and for reversing opioid tolerance and withdrawal in animals. It is not an approved medicine and has never been tested in human trials; any real-world use is off-label, unregulated experimentation.
How does SR-17018 work?
It is a biased partial agonist at the mu-opioid receptor, meaning it favors G-protein signaling (linked to analgesia) over beta-arrestin-2 recruitment (linked to tolerance and breathing suppression). The theory is that this bias could keep the pain relief while trimming the classic opioid harms.
Is SR-17018 well-researched?
Only preclinically. There is solid animal and receptor-pharmacology work, but the "safer opioid" claim is genuinely disputed in the literature, and there are no human studies, so its real-world safety and effectiveness are unknown.
Is SR-17018 legal?
Its status is tightening. In the United States the DEA moved to place it in Schedule I under temporary emergency scheduling (a step that met some opposition), and it may also be reached by the Federal Analogue Act. Germany controls it under the NpSG, and in the UK it falls under the Psychoactive Substances Act.
What are the main risks?
Physical dependence and withdrawal, possible respiratory depression and overdose like any opioid, and the added danger of buying an unregulated research chemical that may be mislabeled, mis-dosed, or contaminated.
Limitations of the evidence
- Still causes physical dependence and withdrawal in animal models; not non-addictive
- Conflicting animal data on respiratory safety, with oral dosing looking less favorable
- No human clinical safety data at all
Adverse effects
- As a mu-opioid agonist it can still cause life-threatening respiratory depression and overdose
Notes and cautions
- Sold as an unregulated research chemical; mislabeling, incorrect dosing, and contamination are real hazards