Research Only Immune & Anti-Inflammatory

Substance P

also known as: SP, Neurokinin 1, NK1 ligand

The pain and nausea neuropeptide — an 11-amino-acid tachykinin that transmits pain signals and triggers vomiting, targeted by aprepitant (Emend) and the entire NK1 antagonist drug class.

An undecapeptide neurotransmitter released from sensory C-fibers and central neurons, binding the NK1 receptor to mediate pain perception, neurogenic inflammation, emesis, and stress-related mood disorders.

Mechanism of action

Binds the NK1 receptor (neurokinin 1, a Gq-coupled GPCR) in the dorsal horn (pain transmission), area postrema/NTS (emesis), amygdala/hypothalamus (stress/anxiety), and peripheral sensory nerves (neurogenic inflammation — vasodilation, plasma extravasation, mast cell degranulation). Released from C-fiber nerve terminals in an axon reflex pattern. Also activates NK2 and NK3 at high concentrations.

Primary uses

Pain transmission research
Emesis physiology (NK1 receptor target)
Neurogenic inflammation studies
Mood and stress disorder research

Typical dosing

Not established

Endogenous neuropeptide. Not administered therapeutically. NK1 antagonists are the therapeutic class.

Regulatory status

Not administered therapeutically. NK1 receptor antagonists (aprepitant/Emend, fosaprepitant, netupitant) are FDA-approved for chemotherapy-induced and postoperative nausea/vomiting.

References

[review] Steinhoff MS, et al. "Tachykinins and their receptors: contributions to physiological control and the mechanisms of disease." Physiol Rev, 2014;94:265-301.

Related peptides

VIP

An endogenous 28-amino-acid peptide with vasodilatory, bronchodilatory, and immunomodulatory effects; explored in sarcoidosis, CIRS/mold illness, and acute respiratory distress.

Alpha-MSH

The endogenous anti-inflammatory melanocortin — the 13-amino-acid POMC fragment that PT-141, melanotan, setmelanotide, and the entire melanocortin drug class are built on.

KPV

A tripeptide derived from α-MSH with potent anti-inflammatory activity — studied in preclinical models of IBD, psoriasis, and acne.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.