DAMGO is a selective peptide agonist of the µ-opioid receptor .

Nocistatin 是一种神经肽，是孤儿类阿片受体的内源性配体。 Nocistatin 还是神经肽伤害感受肽或孤啡肽 FQ (Noc/OFQ) 的功能性拮抗剂。Nocistatin 通过 Gi/o 蛋白介导途径抑制 5-HT 释放。Nocistatin 阻断 Nociceptin 诱导的异常性疼痛和痛觉过敏。

Bovine adrenal medulla docosapeptide (BAM-22P) is a potent opioid agonist, derived from the proenkephalin A gene, which is present in the adrenal medulla.

[Met5]-Enkephalin, amide, is an agonist for δ opioid receptors and putative ζ (zeta) opioid receptors. Met-enkephalin circulates in several forms, some potentially derived from proteins other than proenkephalin A, with plasma levels including both free and bound forms.

Ac-RYYRWK-NH2 is a highly effective and specific partial agonist for the nociceptin receptor (NOP). It demonstrates a remarkable affinity for rat cortical membranes ORL1, with [3H]Ac-RYYRWK-NH2 exhibiting a Kd value of 0.071 nM. However, it shows negligible affinity towards μ-, κ-, or δ-opioid receptors.

(R,S)-Ivosidenib is the less active enantiomer of Ivosidenib .