Side-by-side · Research reference

GHRP-2vsKisspeptin-10

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 2HUMAN-REVIEWED10/41 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

Kisspeptin-10

Neuropeptide · GPR54 Agonist

GnRH pulse generatorPrimary roleSilva 2026

Phase 1/2Clinical stage

GPR54/Kiss1RTarget receptorRønnekleiv 2026

IV / SQ · Investigational

01Mechanism of Action

Parameter

GHRP-2

Kisspeptin-10

Primary target

Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990

GPR54/Kiss1R on hypothalamic GnRH neuronsRønnekleiv 2026 Collado-Sole 2026

Pathway

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

Kisspeptin → GPR54 activation → GnRH neuronal depolarization → Pulsatile GnRH release → Pituitary LH/FSH secretionLages 2026 Rønnekleiv 2026

Downstream effect

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

Pulsatile LH surge, FSH elevation, gonadal steroidogenesis, gametogenesis initiationLages 2026

Feedback intact?

Yes, with somatostatin feedback active

Yes — integrates estradiol, leptin, and IGF-1 signals to modulate HPG axisSilva 2026 Rønnekleiv 2026

Origin

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

C-terminal decapeptide of KISS1 gene product; retains full biological activity of longer kisspeptin isoforms

Antibody development

—

02Dosage Protocols

Parameter

GHRP-2

Kisspeptin-10

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 1/2 trials

Duration

8–12 weeks on / 4 off (anecdotal)

—

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

—

Half-life

~30 minMalagón 1999

Short (minutes)

Rapid clearance; pulsatile dosing mimics physiological GnRH pulse frequency.

Clinical trial dose

—

Phase 1/2 investigational

Dosing protocols vary by indication (hypothalamic amenorrhea, IVF trigger).

Route

—

IV or SQ administration

IV preferred in controlled trials for precise pulsatile delivery.

04Side Effects & Safety

Parameter

GHRP-2

Kisspeptin-10

Cortisol elevation

Mild but measurableBowers 1990

—

Prolactin elevation

Mild but measurable

—

Hunger

Strong appetite increase

—

Injection site reaction

Mild erythema

Erythema, mild discomfort (SQ route)

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy

—

Pregnancy / OB

Avoid

—

Ovarian hyperstimulation

—

Theoretical risk with supraphysiological dosing in fertility protocols

Headache

—

Mild, reported in early-phase trials

Nausea

—

Transient GI symptoms with IV bolus

Hot flashes

—

Vasomotor symptoms from LH surge

Absolute Contraindications

GHRP-2

·Active malignancy
·Pregnancy / breastfeeding

Kisspeptin-10

·Active pregnancy
·Hormone-sensitive malignancy (breast, ovarian, endometrial)

Relative Contraindications

GHRP-2

·Untreated diabetes

Kisspeptin-10

·Polycystic ovary syndrome (PCOS) without monitoring
·Uncontrolled thyroid dysfunction

05Administration Protocol

Parameter

GHRP-2

Kisspeptin-10

1. Reconstitution

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

Reconstitute with sterile water or saline per protocol. Gently swirl — do not shake. Solution should be clear and colorless.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

IV infusion for pulsatile delivery in clinical trials; SQ for outpatient protocols. IV allows precise temporal control of GnRH pulse frequency.

3. Timing

Pre-sleep + fasted preferred.

Pulsatile dosing (e.g., every 60–90 min) mimics physiological GnRH pulse generator. Single-bolus protocols used for LH surge induction in fertility research.

4. Storage

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

Serial LH, FSH, estradiol measurements to confirm HPG axis activation. Ultrasound monitoring for ovarian response in fertility applications.

5. Needle

29–31G, 4–8 mm insulin syringe.

Lyophilized: store at 2–8 °C, light-protected. Reconstituted: refrigerate, use within 24–48 hours per protocol.

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

Kisspeptin-10

— no documented stacks