Substance P
Also known as: SP, Tachykinin
A neuropeptide involved in pain transmission and neuroinflammation. Researched for neuroprotection and cognitive function through NK1 receptor modulation.
Research Status
Clinical trials
For research purposes only. Not approved for human use. Not medical advice.
Research Areas
Side Effects
Mild erythema, swelling, or itching at the injection site typically resolves within 1-2 hours. Rotate injection sites to minimize local reactions. Apply ice if needed.
May occur within 1-4 hours of injection. Usually self-resolving. Ensure adequate hydration and consider timing of injection relative to meals.
Transient vasodilation may occur shortly after injection. Typically resolves within 30 minutes. Not dangerous but may be uncomfortable.
May occur if injected on an empty stomach. Take with a light meal or snack. Usually mild and self-limiting.
May occur if standing too quickly after injection. Sit or lie down for 5-10 minutes post-injection if this occurs.
Substance P is involved in stress and anxiety pathways. Some users report transient mood changes. Monitor closely and discontinue if significant anxiety develops. Consult a healthcare provider.
Chronic repeated injections at the same site can cause localized fat loss or hypertrophy. Strict site rotation (minimum 1 inch between injections) is essential to prevent this. If lipodystrophy develops, discontinue injections at that site for at least 4-6 weeks.
Anaphylaxis or severe allergic reactions are rare but possible. Symptoms include difficulty breathing, throat tightness, severe swelling, or rash. Seek emergency medical attention immediately if these occur. Have an epinephrine auto-injector available if you have a history of peptide allergies.
Substance P can affect cardiovascular tone. If you experience rapid heartbeat, chest discomfort, or palpitations, discontinue use and seek medical evaluation.
Dosing Reference
| Parameter | Value |
|---|---|
| Dose range | 0.1-1 mcg |
| Frequency | 1-2x daily |
| Timing | Morning and/or evening for consistent NK1 receptor occupancy |
| Route | Subcutaneous |
Substance P is typically administered at very low doses due to high potency. Start at the lower end (0.1 mcg) and titrate based on response and tolerability. For research purposes only.
Research disclaimer
Figures drawn from published research literature and community logs. Not clinical recommendations. Consult a qualified professional. Research use only.
Reconstitution Guide
Do not use saline or bacteriostatic saline — use only bacteriostatic water for reconstitution
Do not shake the vial vigorously; gentle swirling prevents peptide degradation
Discard immediately if the solution appears cloudy, discolored, or contains visible particles
Use within 30 days of reconstitution when stored at 2–8°C
Do not freeze the reconstituted solution; freezing may denature the peptide
Use the PeptideVolt reconstitution calculator for your exact concentration
Molecular and Pharmacological Data
| Molecular weight | 1347.6 |
| Half-life | Approximately 2-3 minutes in plasma; longer in CNS tissue |
| Sequence | RPKPQQFFGLM-NH2 |
Substance P is an 11-amino acid neuropeptide that acts primarily as a neurotransmitter and neuromodulator by binding to neurokinin-1 (NK1) receptors on neurons and immune cells. It plays a central role in pain signal transmission, neuroinflammation, and stress responses. Research suggests that modulating substance P signaling may reduce neuroinflammatory cascades, support neuroprotection, and enhance cognitive function through altered pain perception and immune regulation.
NK1 Receptor Signaling
Substance P binds to NK1 receptors, activating G-protein coupled receptor signaling that increases intracellular calcium and triggers downstream phosphorylation cascades. This pathway is central to pain transmission in the spinal cord and brain.
Neuroinflammatory Modulation
Substance P regulates release of pro-inflammatory cytokines (IL-6, TNF-α) from microglia and immune cells. Modulating this pathway may reduce neuroinflammation associated with neurodegenerative conditions.
Stress and Anxiety Response
Substance P is involved in the hypothalamic-pituitary-adrenal (HPA) axis and amygdala function. NK1 receptor antagonism has been studied for anxiolytic and antidepressant effects.
Neuroplasticity and Synaptic Function
Substance P influences long-term potentiation (LTP) and synaptic plasticity through NMDA receptor interactions, potentially supporting learning and memory consolidation.
- Substance P is an 11-amino acid tachykinin neuropeptide with high potency at nanomolar concentrations
- NK1 receptors are widely distributed in the central and peripheral nervous systems, particularly in pain-processing regions (dorsal horn, amygdala, hypothalamus)
- Substance P is co-released with glutamate in pain pathways and amplifies nociceptive signaling
- NK1 receptor antagonists have shown efficacy in clinical trials for depression, anxiety, and chronic pain conditions
- Substance P also functions as an immune modulator, affecting T-cell activation and cytokine production
- The peptide crosses the blood-brain barrier poorly in its native form; research formulations may use modified analogs or delivery systems
Track your Substance P research
Free account. No credit card required.
Browse the Research Library
40+ peptide profiles with mechanism summaries, dosing data, and reconstitution guides.
View all peptidesResearch Use Only. All content on this page is provided for informational and educational purposes related to scientific research. Substance P is not approved for human use by the FDA or any equivalent regulatory body. This is not medical advice. Do not use any substance discussed here for therapeutic, diagnostic, or preventative purposes. Consult a qualified healthcare professional before making any health-related decisions. The Peptide Volt does not endorse the use of any research chemicals. 18+ only.