Side-by-side · Research reference

IpamorelinvsVIP

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

APhase 1HUMAN-REVIEWED21/57 cited

BPhase 3HUMAN-REVIEWED9/42 cited

Ipamorelin

Selective GHRP · Ghrelin Mimetic

200–300 mcgPer doseRaun 1998

Phase 1Evidence levelRaun 1998 Sigalos 2018

~2 hrHalf-lifeRaun 1998

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

Ipamorelin

VIP

Primary target

Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998

VPAC1 and VPAC2 G-protein-coupled receptorsUdupa 2025

Pathway

GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998 Bowers 1991

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

Downstream effect

GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002

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

Feedback intact?

Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002

Yes — exogenous VIP acts as physiological agonist

Origin

Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998

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

Antibody development

Not reported in short-term studies

—

02Dosage Protocols

Parameter

Ipamorelin

VIP

Standard dose

200–300 mcg per injectionRaun 1998

Anecdotal community range; clinical doses 1–3 mg IV in trials.

—

Frequency

1–3× per day

Once daily pre-sleep is most common; twice or thrice for advanced users.

—

Lower / starter dose

100 mcg per dose

—

Evidence basis

Phase 1 + clinical practiceRaun 1998 Sigalos 2018

Phase 3 RCT (TESICO)Brown 2023

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

Duration

8–12 weeks on / 4 weeks off (anecdotal)

GHS-R desensitisation reported with continuous dosing.

—

Reconstitution

Bacteriostatic water; typical 2 mL per 5 mg vial

Lyophilized powder reconstituted with sterile diluent per protocol

Timing

Pre-sleep + fasted preferred; 30 min away from food

—

Half-life

~2 hoursRaun 1998

Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).

~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

Ipamorelin

VIP

Cortisol elevation

Negligible vs other GHRPsRaun 1998

—

Prolactin elevation

NegligibleRaun 1998

—

Hunger

Mild appetite increase via ghrelin-receptor crosstalk

—

Injection site reaction

Mild irritation possible

—

GH excess (overdose)

Joint pain, edema, insulin resistance

—

IGF-1 elevation

Dose-dependent; monitor with chronic high-dose use

—

Cancer risk

Theoretical via GH/IGF-1 axis; 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

Ipamorelin

·Active malignancy or cancer history
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

VIP

·Known hypersensitivity to aviptadil or formulation components

Relative Contraindications

Ipamorelin

·Untreated diabetes
·Severe insulin resistance
·Concurrent corticosteroid use (theoretical desensitisation)

VIP

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

05Administration Protocol

Parameter

Ipamorelin

VIP

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL. Roll gently. Solution should be clear.

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

2. Injection site

Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.

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 optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.

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, protected from light. Reconstituted: refrigerate 2–8 °C, use within 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

Ipamorelin

+ Tesamorelin

Strong

View Tesamorelin →

Ipamorelin (GHRP) + tesamorelin (GHRH analogue) is the textbook dual-axis GH stack. They activate two distinct pituitary receptors — the ghrelin receptor and the GHRH receptor — producing a synergistic GH pulse larger than either alone. Ipamorelin's selectivity (no cortisol/prolactin spike) makes it the ideal GHRP partner for long-term protocols.

Ipamorelin: 200–300 mcg SQ · pre-sleep
Tesamorelin: 2 mg SQ · same injection · pre-sleep
Primary benefit: Maximal GH pulsatility, fat loss, recovery, sleep depth

Raun 1998 Bowers 2002

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

CJC-1295 (no DAC) is a short-acting GHRH analogue. Combined with ipamorelin (GHRP), the pulse is amplified across both receptor systems with timing similar to native physiology. Without the DAC modification, the stack maintains sharp peaks rather than the sustained elevation seen with CJC-1295-DAC + ipamorelin.

Ipamorelin: 200–300 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation matching physiological pattern

Teichman 2006 Ionescu 2006

VIP

— no documented stacks