Substance P
Neuropeptide / TachykininresearchAlso known as: SP, Neurokinin 1, Tachykinin
An 11-amino acid neuropeptide involved in pain transmission, inflammation, and emotional stress responses, primarily acting through the neurokinin-1 (NK1) receptor.
Overview
Substance P is an undecapeptide belonging to the tachykinin family, first discovered in 1931 and sequenced in 1971. It is widely distributed in the central and peripheral nervous systems, with particularly high concentrations in dorsal root ganglia, the substantia nigra, and the hypothalamus. Substance P plays a key role in nociception (pain signaling), neurogenic inflammation, and emotional regulation. It transmits pain signals from peripheral sensory neurons to the spinal cord and brain, and triggers inflammatory responses including vasodilation, plasma extravasation, and immune cell activation. NK1 receptor antagonists (like aprepitant) have been developed as antiemetics and are being explored for depression and pain conditions.
Mechanism of Action
Substance P signals primarily through the NK1 receptor: (1) Released from C-fiber sensory neurons in response to noxious stimuli, transmitting pain signals to the dorsal horn; (2) Causes neurogenic inflammation through vasodilation, increased vascular permeability, and mast cell degranulation; (3) Modulates mood and stress responses through central NK1 receptors in the amygdala and hypothalamus; (4) Stimulates immune cells including macrophages, T cells, and dendritic cells; (5) Promotes wound healing through stimulation of fibroblast proliferation and angiogenesis; (6) Triggers the emetic reflex through NK1 receptors in the brainstem.
Molecular Formula
C63H98N18O13S
Molecular Weight
1347.63 g/mol
Sequence
Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2
Dosage Protocols
Dose Range
N/A – N/A
Frequency
N/A
Route
N/A
Cycle Length
N/A
Substance P is not used therapeutically. Its clinical relevance is through NK1 receptor antagonists that block its action. Aprepitant (Emend) 125mg/80mg is the approved NK1 antagonist for chemotherapy-induced nausea.
Source: Research literature
🧮 Personalized Dosage Calculator
💰 Estimated Pricing
Typical Supply
1mg vial
Last Updated
2026-02
Neuropeptide involved in pain signaling. Research-grade only. Academic/research suppliers. Not used therapeutically as peptide.
⚠️ Prices are estimates based on publicly available data and may vary significantly by vendor, location, and prescription status. This is not medical or financial advice.
Side Effects
| Effect | Severity |
|---|---|
| Not applicable (endogenous) | mild |
Pros & Cons
Fundamental to understanding pain physiology and neurogenic inflammation
NK1 receptor antagonist drugs derived from SP research have clinical applications (antiemetics, potential antidepressants)
Plays beneficial roles in wound healing and immune defense
Not used as a therapeutic agent — clinical relevance is through its antagonism
Elevated Substance P levels are associated with chronic pain, inflammatory diseases, and mood disorders
NK1 antagonists for depression have had mixed clinical trial results
Research Studies
🩸 Blood Work
No specific bloodwork requirements reported for this peptide. General health panels are always recommended before starting any peptide protocol.
Legal Status
Endogenous neuropeptide. Available as a research reagent. NK1 receptor antagonists (aprepitant/Emend) are FDA-approved as antiemetics. Not used therapeutically as an exogenous peptide.
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