4-MethoxymethylFentanyl For sale online

R-30490 (also known as 4-Methoxymethylfentanyl) is an opioid analgesic related to the highly potent animal tranquilizer carfentanil and with only slightly lower potency. It was first synthesized by a team of chemists at Janssen Pharmaceutica led by Paul Janssen, who were investigating the structure-activity relationships of the fentanyl family of drugs. R-30490 was found to be the most selective agonist for the μ-opioid receptor out of all the fentanyl analogs tested, but it has never been introduced for medical use in humans, although the closely related drug sufentanil is widely used for analgesia and anesthesia during major surgery.