FK 33-824

FK 33-824 is a **synthetic analog of methionine-enkephalin** designed to provide longer-lasting and more potent analgesic effects than natural enkephalins. It is a pentapeptide with the sequence D-Ala2, N-Me-Phe4, Met(O)-ol5-enkephalin. FK 33-824 acts primarily as a **selective agonist at the μ-opioid receptor** (mu-opioid receptor), with less affinity for the delta-opioid receptor and negligible affinity for kappa-opioid receptors. It produces morphine-like analgesic effects by stimulating opioid receptors, shows cross-tolerance with morphine, can induce dependence, and its effects are antagonized by naloxone. FK 33-824 has been shown to increase pain tolerance in humans, alter gastrointestinal motility, and affect endocrine and metabolic responses. It has been studied clinically but is not known to be marketed as a therapeutic.

Other names

DAMMED-Ala2, N-Me-Phe4, Met(O)-ol5-enkephalin(D-Ala²,N-Me-Phe⁴,methionin(O)-ol⁵)-EnkephalinCAS 64854-64-4CAS64854-64-4CAS-64854-64-4