Peptide Database

Leu-Enkephalin · Met-Enkephalin

Enkephalins are endogenous opioid pentapeptides (Met-enkephalin and Leu-enkephalin) acting as natural ligands for delta and mu opioid receptors. They modulate pain, mood, reward, and immune function. Low-dose naltrexone (LDN) works partly by transiently blocking opioid receptors to upregulate enkephalin production. Methionine enkephalin (met-enkephalin) has shown immune-modulating and anti-tumor properties in research, particularly for HIV and cancer.

NT · NTS

Neurotensin is a 13-amino-acid neuropeptide found in the brain and GI tract. Centrally, it modulates dopamine circuits, acts as an endogenous antipsychotic-like agent, and is analgesic. Peripherally, it inhibits gastric acid secretion, stimulates pancreatic secretion, and promotes fat absorption. Research explores neurotensin analogs for pain, schizophrenia, Parkinson's disease, and metabolic regulation.

Alpha-Melanocyte-Stimulating Hormone · α-Melanotropin

α-MSH is an endogenous 13-amino-acid peptide derived from POMC (pro-opiomelanocortin). It activates MC1R to stimulate melanin production in skin, MC4R to suppress appetite and regulate energy expenditure, and MC3R/MC1R to exert potent anti-inflammatory effects. It is the parent compound from which many synthetic melanocortin analogs (Melanotan I, II, PT-141, KPV) were derived and remains a cornerstone of melanocortin pharmacology research.