Overview

GHRP-2 (Growth Hormone Releasing Peptide-2), also known as Pralmorelin, is a second-generation synthetic hexapeptide that stimulates growth hormone release through the ghrelin receptor. Developed as an improvement over first-generation GHRP-6, it offers potent GH stimulation with somewhat reduced appetite effects.

GHRP-2 occupies a middle ground in the GHRP family - more potent than Ipamorelin but with fewer side effects than GHRP-6, making it a popular choice for those seeking significant GH elevation.

Key Characteristics

Origin: Synthetic hexapeptide (6 amino acids)
Classification: Second-generation GHRP, Ghrelin receptor agonist
Sequence: D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2
Distinguishing Feature: Balanced potency/side effect profile
Approved Use: Diagnostic agent in Japan (Pralmorelin)

The GHRP Spectrum

| GHRP | Generation | GH Release | Appetite | Cortisol | Prolactin | |------|------------|------------|----------|----------|-----------| | GHRP-6 | 1st | +++++ | +++++ | ++ | ++ | | GHRP-2 | 2nd | +++++ | +++ | ++ | ++ | | Hexarelin | 2nd | +++++ | ++ | +++ | +++ | | Ipamorelin | 3rd | +++ | + | - | - |

GHRP-2 offers potency similar to GHRP-6 with reduced (but not eliminated) appetite stimulation.

Mechanism

Primary Mechanisms

1. Ghrelin Receptor (GHS-R1a) Activation

GHRP-2 is a potent ghrelin mimetic:

Binds to growth hormone secretagogue receptor in pituitary
Triggers calcium signaling cascades
Stimulates GH release from somatotrophs
More selective than GHRP-6 for GH release

2. Hypothalamic Effects

GHRP-2 also acts on the hypothalamus:

Stimulates GHRH release
Suppresses somatostatin release
Creates amplified pituitary response
Dual action enhances overall effect

3. Moderate Appetite Stimulation

Unlike GHRP-6's intense hunger:

Appetite increase present but manageable
Most prominent 20-30 minutes post-injection
Duration shorter than GHRP-6
Can be timed strategically around meals

4. Secondary Hormone Effects

GHRP-2 affects other hormones:

Modest cortisol elevation (dose-dependent)
Modest prolactin elevation (dose-dependent)
Effects less pronounced than Hexarelin
Generally not clinically significant at standard doses

Research

Research Note: GHRP-2 is one of the better-studied GHRPs, with research in both healthy subjects and various clinical conditions. It is approved in Japan for diagnostic use.

Growth Hormone Release

Clinical Studies

GHRP-2 has been studied extensively:

Reliable, dose-dependent GH release
Peak GH levels 30-60 minutes post-injection
Greater magnitude than Ipamorelin
Consistent response over time

Comparative Potency

Research shows:

Similar GH release to GHRP-6
2-3x greater GH release than Ipamorelin
Synergistic with GHRH analogs
Response varies by age and body composition

Clinical Applications

GH Deficiency Diagnosis

Approved in Japan for:

Provocative testing of GH secretion
Diagnosis of growth hormone deficiency
Assessment of pituitary function

Body Composition

Studies indicate:

Increased lean body mass
Decreased fat mass
Improved muscle strength
Enhanced recovery from exercise

Anti-Aging Research

Somatopause Research

Studies in older adults show:

Effective GH stimulation despite age
Improved sleep quality
Enhanced physical performance
Potential cognitive benefits

Cardiovascular Effects

Cardioprotective Research

Some studies suggest:

Potential cardioprotective effects
Reduced ischemic damage in animal models
May improve cardiac function
Needs more human research

Dosing

Disclaimer: GHRP-2 is not FDA-approved for human therapeutic use (approved in Japan for diagnostic purposes only). All dosing information is for research reference.

Research Protocols

Protocol	Dose	Frequency	Duration
Standard	100-200 mcg	2-3x daily	8-12 weeks
With GHRH	100 mcg each	2-3x daily	8-12 weeks
Conservative	100 mcg	Twice daily	8-12 weeks
Aggressive	200-300 mcg	3x daily	8-12 weeks

Optimal Timing

Best Times for Injection

Upon waking (fasted state)
Post-workout
Before bed (important for sleep GH pulse)

Timing Considerations

Fasted state enhances GH release
Wait 20-30 minutes before eating
Can eat to manage appetite effect
Avoid high-fat meals close to injection

The Saturation Dose

~100 mcg represents saturation per dose
Higher doses don't proportionally increase GH
But may increase appetite and side effects
100 mcg 2-3x daily often optimal

Reconstitution

Use bacteriostatic water
Standard: 5mg vial + 2.5ml water = 2mg/ml
Refrigerate after reconstitution
Stable for 4-6 weeks
Protect from light

Synergy & Stacking

The GHRH + GHRP Synergy

Multiplicative Effect

Combining GHRH analog with GHRP-2 creates synergy:

GHRP-2 suppresses somatostatin ("releases brake")
GHRH presses the "accelerator"
Combined effect is multiplicative, not additive
3-10x greater GH release than either alone

Common Combinations

GHRP-2 + CJC-1295 (No DAC)

When to Choose GHRP-2

Choose GHRP-2 over alternatives when:

Want potent GH release
Some appetite stimulation acceptable/desired
Looking for balance between GHRP-6 and Ipamorelin
Budget allows for mid-tier option

Comparison: GHRP-2 vs Alternatives

| Feature | GHRP-2 | GHRP-6 | Ipamorelin | |---------|--------|--------|------------| | GH Release | +++++ | +++++ | +++ | | Appetite | +++ | +++++ | + | | Cortisol | ++ | ++ | - | | Prolactin | ++ | ++ | - | | Selectivity | Medium | Low | High | | Best For | Balance | Bulking | Cutting/Clean |

Safety

Known Side Effects

Common

Moderate appetite increase
Water retention (dose-dependent)
Fatigue/drowsiness (especially bedtime dose)
Tingling/numbness (high doses)
Headache (usually temporary)

Less Common

Flushing
Joint aches
Mild cortisol elevation
Mild prolactin elevation

Compared to GHRP-6

Less intense hunger
Similar water retention potential
Similar cortisol/prolactin effects
Slightly better tolerability overall

Contraindications

Avoid or use with caution if:

Active cancer or cancer history
Diabetic (glucose effects possible)
History of prolactinoma
Pregnancy or breastfeeding
Under 18 (without medical supervision)

Appetite Note: While less than GHRP-6, GHRP-2's appetite stimulation can still be significant. Those strictly dieting may prefer Ipamorelin.

Drug Interactions

May affect glucose metabolism
Potential interaction with diabetes medications
Caution with corticosteroids
Generally compatible with most medications

Monitoring

Baseline Assessments

IGF-1 level
Fasting glucose/HbA1c
Prolactin (optional)
Body composition

During Use

IGF-1 (every 3-6 months)
Weight and composition tracking
Appetite and side effect logging
Glucose if diabetic

Signs to Monitor

Excessive water retention
Carpal tunnel symptoms
Persistent fatigue
Glucose changes

Regulatory

Current Status

| Region | Status | |--------|--------| | United States | Not FDA approved; research chemical | | Japan | Approved for diagnostic use (Pralmorelin) | | WADA | Strictly Prohibited (S2 category) | | Detection | Detectable for days post-use |

Legal Considerations

Available as research chemical in most countries
Not approved for therapeutic use (except Japan diagnostics)
Athletes: Strictly banned in competition
Quality varies by supplier

Clinical Status

GHRP-2 (Pralmorelin) is:

The only GHRP approved for any medical use
Used diagnostically in Japan since 2004
Provides validation of efficacy and safety
May pave way for future therapeutic approvals

References

[1] Bowers CY, et al.. On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology (1984)

[2] Kojima M, et al.. Ghrelin and growth hormone secretagogues. Trends in Endocrinology & Metabolism (2001)

[3] Arvat E, et al.. Preliminary evidence for an interaction between GHRP-2 and cortisol secretion in humans. Journal of Clinical Endocrinology & Metabolism (1994)

[4] Takaya K, et al.. Ghrelin and growth hormone secretagogue receptor. Vitamins and Hormones (2012)

[5] Clinical GHRP Research. Growth Hormone Secretagogues: Clinical Applications and Future Directions. Growth Hormone & IGF Research (2025)