Side-by-side · Research reference

GHRP-2vsVIP

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED15/42 cited

BPhase 3HUMAN-REVIEWED9/42 cited

GHRP-2

Hexapeptide GHRP · Phase 2 (clinical diagnostic)

100–300 mcgPer doseBowers 1990

Phase 2Evidence levelBowers 1990 Sigalos 2018

~30 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

VIP

Neuropeptide · VPAC1/VPAC2 Agonist · Emergency Use Authorization (COVID-19 ARDS)

IntravenousPrimary routeBrown 2023

ARDSLead indicationUdupa 2025

Phase 3Development stage

IV infusion · Inhaled (investigational)Brown 2023 Boesing 2022

01Mechanism of Action

Parameter

GHRP-2

VIP

Primary target

Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990

VPAC1 and VPAC2 G-protein-coupled receptorsUdupa 2025

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002

VIP → VPAC1/VPAC2 activation → cAMP elevation → Pulmonary vasodilation + epithelial protection

Downstream effect

Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002

Anti-inflammatory cytokine modulation, alveolar-capillary membrane stabilization, pulmonary smooth muscle relaxation, reduced neutrophil infiltration

Feedback intact?

Yes, with somatostatin feedback active

Yes — exogenous VIP acts as physiological agonist

Origin

Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990

Endogenous 28-amino-acid neuropeptide; synthetic analogue (aviptadil) identical to natural VIP

Antibody development

—

02Dosage Protocols

Parameter

GHRP-2

VIP

Standard dose

100–300 mcg per injectionBowers 1990

—

Frequency

1–3× per day

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 2 + clinical diagnostic useBowers 1990

Phase 3 RCT (TESICO)Brown 2023

816-patient randomized controlled trial in COVID-19 ARDS.

Duration

8–12 weeks on / 4 off (anecdotal)

—

Reconstitution

Bacteriostatic water

Lyophilized powder reconstituted with sterile diluent per protocol

Timing

Pre-sleep + fasted preferred

—

Half-life

~30 minMalagón 1999

~2 minutes (plasma)

Rapid clearance necessitates continuous infusion.

Intravenous (ARDS protocol)

—

60–90 mcg/kg/day via continuous infusion

TESICO trial protocol for COVID-19 ARDS.

Infusion duration

—

12-hour continuous IV infusion dailyBrown 2023

Inhaled (investigational)

—

Variable dosing under clinical trial protocolsBoesing 2022

Delivered via nebulizer for direct pulmonary deposition.

Treatment duration

—

3–14 days (acute ARDS)

04Side Effects & Safety

Parameter

GHRP-2

VIP

Cortisol elevation

Mild but measurableBowers 1990

—

Prolactin elevation

Mild but measurable

—

Hunger

Strong appetite increase

—

Injection site reaction

Mild erythema

—

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy

—

Pregnancy / OB

Avoid

—

Hypotension

—

Transient vasodilation-related blood pressure drop

Tachycardia

—

Reflex tachycardia secondary to vasodilation

Infusion site reactions

—

Erythema, phlebitis (IV administration)

GI symptoms

—

Nausea, diarrhea (VIP is endogenous GI peptide)

Overall tolerability

—

Well-tolerated in Phase 3 trials; adverse event profile comparable to placebo

Absolute Contraindications

GHRP-2

·Active malignancy
·Pregnancy / breastfeeding

VIP

·Known hypersensitivity to aviptadil or formulation components

Relative Contraindications

GHRP-2

·Untreated diabetes

VIP

·Severe hypotension or shock states (monitor blood pressure)
·Pregnancy — insufficient safety data

05Administration Protocol

Parameter

GHRP-2

VIP

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.

Reconstitute lyophilized aviptadil powder with sterile diluent per manufacturer protocol. Inspect solution for particulates — should be clear and colorless.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Administer as continuous 12-hour intravenous infusion via central or peripheral line. Use infusion pump for precise dosing (60–90 mcg/kg/day divided over infusion duration).

3. Timing

Pre-sleep + fasted preferred.

Monitor blood pressure, heart rate, and oxygenation continuously during first infusion. Assess for hypotension and adjust infusion rate if needed.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

Deliver via jet or mesh nebulizer per clinical trial protocol. Patient seated upright, normal tidal breathing for 10–15 minutes.

5. Needle

29–31G, 4–8 mm insulin syringe.

Store lyophilized powder at 2–8 °C, light-protected. Reconstituted solution: use immediately or within 24 hours if refrigerated.

06Stack Synergy

GHRP-2

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

GHRP-2 + CJC-1295-no-DAC is a higher-amplitude alternative to the ipamorelin + CJC-1295 stack. GHRP-2 produces a stronger pulse but with cortisol + prolactin signal — choose when maximum GH amplitude is the goal and the side-effect tolerance is acceptable.

GHRP-2: 100–200 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: High-amplitude GH pulse, body composition

Bowers 1990 Teichman 2006

VIP

— no documented stacks