GHRP-2
Also known as: Growth Hormone Releasing Peptide-2 · Pralmorelin
Contents
MW
817.97 Da
Amino Acids
6 AA
Half-Life
1.5-2 hours
Route
SubQ, IV
CAS
158861-67-7
Formula
C45H55N9O6
Amino Acid Sequence
D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2
Mechanism of Action
GHRP-2 (Growth Hormone Releasing Peptide-2, Pralmorelin) is a synthetic hexapeptide GH secretagogue that binds GHS-R1a on pituitary somatotrophs. It produces potent GH release but with LESS selectivity than ipamorelin.
PRIMARY MECHANISM — GHS-R1a ACTIVATION: Same receptor as ipamorelin and ghrelin. Gq-coupled → PLC → IP3/DAG → calcium → GH exocytosis. Also suppresses somatostatin.
CRITICAL DIFFERENCE FROM IPAMORELIN: GHRP-2 produces significant elevations of cortisol (via ACTH stimulation) and prolactin in addition to GH. This "dirty" profile means GHRP-2 stimulates the adrenal axis — not just the GH axis. At GH-releasing doses, cortisol elevation is clinically meaningful. Prolactin elevation may cause gynecomastia with chronic use.
APPETITE STIMULATION: Moderate appetite increase via ghrelin-like effects on gut receptors — more than ipamorelin but less than GHRP-6.
POTENCY: Stronger GH release per-dose than ipamorelin, making it useful when maximum GH output is desired and side effects are acceptable.
Generally less preferred than ipamorelin for clinical use due to the cortisol/prolactin profile, but still used when GH potency is prioritized.
Dosing Protocol
Low Dose
███ – ███ mcg/day
Standard Dose
███ mcg/day
High Dose
███ – ███ mcg/day
Dosing protocols are for paid members
Get exact dosing ranges, injection frequency, timing rationale, and reconstitution math.
Get Clinical Access — $79/moFrequency
2–3x daily, fasted.
Half-Life
1.5-2 hours
Reconstitution Guide
Full reconstitution protocol with BAC water volumes, concentration math, and units-to-draw per dose is available on the Clinical plan.
Unlock reconstitution guide →Clinical Warnings
Cortisol and prolactin elevation — monitor levels.
Strong hunger increase.
Less selective than ipamorelin — more side effects.
WADA prohibited.
Cancer absolute contraindication.
Prolactin elevation may cause gynecomastia.
Contraindications
Absolute
Active cancer
Pregnancy
Relative Cautions
Diabetes
Cushing syndrome
Obesity
History of cancer
Side Effect Profile
Mild
- ●Increased appetite
- ●Water retention
- ●Flushing
Moderate
- ●Elevated cortisol
- ●Elevated prolactin
- ●Headache
- ●Dizziness
Severe (Rare)
- ●Potential tumor growth
- ●Prolactin-related side effects
Synergistic Peptides
Common Stacks
CJC-1295
Ipamorelin
GHRP-6
Research Status
MODERATE. PMID 8617614 (Pandya 1998): GH release characterization vs GHRP-6. PMID 10403255 (Korbonits 1999): cortisol/ACTH elevation demonstrated. Generally replaced by ipamorelin for clinical selectivity.
Frequently Asked Questions
How does GHRP-2 work?
GHRP-2 (Growth Hormone Releasing Peptide-2, Pralmorelin) is a synthetic hexapeptide GH secretagogue that binds GHS-R1a on pituitary somatotrophs. It produces potent GH release but with LESS selectivity than ipamorelin. PRIMARY MECHANISM — GHS-R1a ACTIVATION: Same receptor as ipamorelin and ghrelin. Gq-coupled → PLC → IP3/DAG → calcium → GH exocytosis. Also suppresses somatostatin. CRITICAL DIFFERENCE FROM IPAMORELIN: GHRP-2 produces significant elevations of cortisol (via ACTH stimulation) and
What is the standard dose of GHRP-2?
GHRP-2 dosing protocols are available with a ClinPep Clinical subscription. Dosing varies by indication and patient factors — consult a licensed healthcare provider. General frequency: 2–3x daily, fasted.
What is the half-life of GHRP-2?
The half-life of GHRP-2 is 1.5-2 hours. This determines optimal dosing frequency and timing.
Who should not use GHRP-2?
GHRP-2 is absolutely contraindicated in: Active cancer; Pregnancy. Use with caution in: Diabetes; Cushing syndrome; Obesity.
What are the side effects of GHRP-2?
Common mild side effects include: Increased appetite, Water retention, Flushing. Moderate effects: Elevated cortisol, Elevated prolactin, Headache, Dizziness.
What peptides stack well with GHRP-2?
GHRP-2 is commonly stacked with: CJC-1295, Ipamorelin, GHRP-6.
How do you reconstitute GHRP-2?
GHRP-2 is reconstituted with bacteriostatic water. Exact volumes, concentrations, and units-to-draw calculations are available in the ClinPep Clinical plan. Always follow your compounding pharmacy's instructions.
How long should you cycle GHRP-2?
GHRP-2 cycle protocols vary by indication. Detailed cycle length, on/off schedules, and monitoring guidelines are available with ClinPep Clinical access. Consult your healthcare provider for personalized cycling guidance.
References & Citations
10 PubMed studies · 0 clinical trials
One Case of Sudden Isolated Adrenocorticotropic Hormone (ACTH) Deficiency Diagnosed Based on Repeated Hypoglycemic Attacks.
Sato Tomohide. Cureus. 2025
Our patient is a 28-year-old male who was being treated by a local doctor for Hashimoto's thyroiditis. Four days prior to admission, nausea and diarrhea appeared, and it gradually became difficult for
Growth Hormone-Releasing Peptide 2 May Be Associated With Decreased M1 Macrophage Production and Increased Histologic and Biomechanical Tendon-Bone Healing Properties in a Rat Rotator Cuff Tear Model.
Li Yinghao, Yao Lei, Zhang Chunsen, Li Tao et al.. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 2025
To explore the potential of growth hormone-releasing peptide 2 (GHRP-2) for tendon-bone healing in a rat rotator cuff tear (RCT) model. The impact of GHRP-2 on M1 macrophage polarization in vitro was
Robust growth hormone responses to GH-releasing peptide 2 in adolescents.
Onuki Takanori, Hiroaki Tadokoro, Sawano Kentaro, Shibata Nao et al.. Journal of pediatric endocrinology & metabolism : JPEM. 2024
GH-releasing peptide-2 (GHRP2) can be used for provocative growth hormone testing (GHT). Since it acts as a powerful stimulus for GH secretion, cut-off peak GH level in GHRP2 loading test (GHRP2T) is
Literature-Based Discovery to Elucidate the Biological Links between Resistant Hypertension and COVID-19.
Kartchner David, McCoy Kevin, Dubey Janhvi, Zhang Dongyu et al.. Biology. 2023
Multiple studies have reported new or exacerbated persistent or resistant hypertension in patients previously infected with COVID-19. We used literature-based discovery to identify and prioritize mult
Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly.
Teramoto Shinichiro, Tahara Shigeyuki, Hattori Yujiro, Kondo Akihide et al.. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society. 2023
The growth hormone (GH)-releasing peptide-2 (GHRP-2) test is relatively safe among endocrine stimulation tests for the elderly. We investigated whether anterior pituitary function in elderly patients
Clinical Usefulness of the Growth Hormone-Releasing Peptide-2 Test for Hypothalamic-Pituitary Disorder.
Suzuki Sawako, Ruike Yutarou, Ishiwata Kazuki, Naito Kumiko et al.. Journal of the Endocrine Society. 2022
Growth hormone deficiency (GHD) develops early in patients with hypothalamic-pituitary disorder and is frequently accompanied by other anterior pituitary hormone deficiencies, including secondary adre
Pharmacotherapy in Cachexia: A Review of Endocrine Abnormalities and Steroid Pharmacotherapy.
Celichowska Magdalena, Miedziaszczyk Miłosz, Lacka Katarzyna. Journal of pain & palliative care pharmacotherapy. 2022
Cachexia is a state of increased metabolism associated with high morbidity and mortality. Dysregulation of cytokines and hormone activity causes reduced protein synthesis and excessive protein breakdo
Idiopathic combined adrenocorticotropin and growth hormone deficiency mimicking chronic fatigue syndrome.
Tokumasu Kazuki, Ochi Kanako, Otsuka Fumio. BMJ case reports. 2021
A 42-year-old man who had suffered from severe fatigue for 5 years was diagnosed as having chronic fatigue syndrome (CFS) and fibromyalgia. Endocrinological workup using combined anterior pituitary fu
Symptom Indications
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Complete GHRP-2 Protocol
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This information is for educational and research reference purposes only. ClinPep does not provide medical advice, diagnosis, or treatment recommendations. All protocols should be reviewed by a licensed healthcare provider.