PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide)
Also known as: PACAP-38, PACAP-27, ADCYAP1
Overview
PACAP is a 38-amino acid neuropeptide (with a shorter 27 AA form) belonging to the secretin/glucagon/VIP superfamily. It is one of the most potent known neuroprotective peptides, safeguarding neurons against ischemic, oxidative, and excitotoxic insults across multiple brain regions. PACAP plays important roles in neuronal differentiation, synaptic plasticity, and circadian rhythm regulation. Its diverse receptor profile and potent activity make it a significant research target for neurodegenerative diseases, traumatic brain injury, and PTSD.
Mechanism of Action
PACAP binds three receptors: PAC1 (ADCYAP1R1, high affinity, PACAP-selective) and VPAC1/VPAC2 (shared with VIP). PAC1 activation stimulates adenylyl cyclase (cAMP/PKA pathway) and phospholipase C (PKC pathway). These pathways activate MAPK/ERK, PI3K/Akt, and CREB-mediated gene expression, promoting expression of anti-apoptotic proteins (Bcl-2) and neurotrophic factors (BDNF, GDNF). PACAP also modulates voltage-gated calcium channels and inhibits caspase-3 activation.
Potential Benefits
- Potent neuroprotection against ischemia and oxidative stress
- Neuronal differentiation support
- Synaptic plasticity and LTP enhancement
- Circadian rhythm regulation
- PTSD-related stress response modulation (PAC1 receptor)
- Potential in TBI and neurodegenerative disease
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | Not a consumer research peptide |
| Intermediate | N/A |
| Advanced | N/A |
| Cycle Duration | N/A — research use |
PACAP-38 or PACAP-27 used in research. Clinical development for migraine (antagonists) — not agonists.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Intravenous (research) 100%
Used in migraine provocation studies.
Intranasal (research) Moderate CNS delivery
Preclinical neuroprotection studies.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide):
Research Context Only
PACAP is a research tool. Migraine therapeutics target PACAP antagonists (e.g. Lundbeck's Lu AG09222).
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Refrigerate at 2-8°C after reconstitution. Do not freeze reconstituted solution. |
|---|
Typical vial sizes: 0.1-1 mg (research). Add bac water slowly down the side of the vial, swirl gently — do not shake. Use insulin syringe for precise dosing.
Need exact syringe measurements?
Amino Acid Sequence
His-Ser-Asp-Gly-Ile-Phe-Thr-Asp-Ser-Tyr-Ser-Arg-Tyr-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Ala-Ala-Val-Leu-Gly-Lys-Arg-Tyr-Lys-Gln-Arg-Val-Lys-Asn-Lys-NH2
Side Effects & Safety
- Vasodilation and hypotension at pharmacological doses
- Nausea
- Headache
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Pregnancy / Lactation
Bleeding Disorders
Active Skin Infection at Injection Site
Pharmacokinetics
| Half-Life | Not well characterized for this peptide; consult primary literature |
|---|---|
| Storage | Store lyophilized peptide at -20°C (long-term) or 2-8°C (short-term, under 30 days). Reconstituted: refrigerate at 2-8°C and use within 28-30 days. Protect from light. Do not freeze reconstituted solution. |
Synergistic Compounds
The following compounds have been studied alongside PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide) for potential complementary or synergistic effects:
Learn More
References & Further Reading
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