At a Glance
Quickcomparison
Dose Range
Pralmorelin (GHRP-2)
100–300 mcg
GHRP-6 (Growth Hormone Releasing Peptide-6)
Frequency
Once daily
Multiple times daily
Administration
Subcutaneous injection
Cycle Length
4-6 weeks
8-12 weeks
Onset Speed
Rapid (hours to days)
Moderate (1-2 weeks)
Evidence Level
Limited human trials
Efficacy
Benefitratings
Muscle & Performance Enhancement
Injury Recovery & Healing
Diagnostic Clinical Use
Muscle Recovery and Growth
Cellular Health and Protection
Appetite and Nutrient Intake
Technical Data
Compoundspecifications
Molecular Formula
C45H55N9O6
Molecular Weight
818.0 g/mol
Half-Life
15-60 minutes
Bioavailability
~100% (subcutaneous injection)
CAS Number
158861-67-7
C46H56N12O6
873.0 g/mol
~2.5 hours
<1% oral, high subcutaneous
87616-84-0
Protocols
Dosingtiers
standard
1 mcg/kg/hour (continuous infusion) in research settings
Continuous infusion
Study-defined (e.g. ~270 minutes in published trials)
Subcutaneous infusion dose used in controlled human GH-release/appetite studies; not an approved therapeutic regimen. [4]
100 mcg (0.1 mg) single bolus (diagnostic GH-stimulation test)
Single administration
Single test; blood sampled at 0, 15, 30, 60 min
Japan-approved diagnostic dose (GHRP Kaken 100) for growth hormone deficiency; fixed 100 mcg IV bolus. A research GH-stimulation dose of 1 mcg/kg IV is also documented. [1]
~100 mcg per injection (approx. 1 mcg/kg)
1-3 times daily, on an empty stomach
Open-ended in research practice
Research-practice GH-secretagogue dosing; the ~100 mcg anchor reflects the validated 1 mcg/kg GH-saturating dose, though no isolated subcutaneous human dose-response trial exists [6].
1 mcg/kg bolus (optionally followed by 1 mcg/kg/hr infusion)
Single bolus for acute GH testing; infusion studies ran up to ~34 hours
Acute test or infusion study
Trial-established near-maximal GH-releasing intravenous dose in healthy men; pituitary responsiveness maintained over prolonged infusion [6].
Applications
Bestsuited for
Athletes and Fitness Enthusiasts
If you're serious about lean muscle gains and recovery, pralmorelin directly stimulates GH release—one of the body's most powerful anabolic hormones. Most athletes in research settings use 100-200 mcg for faster muscle repair and improved performance.
Individuals Recovering from Injury
Recent animal studies show GHRP-2 reduces inflammation and speeds tendon-bone healing. If you're dealing with sports injuries, rotator cuff issues, or fractures, this peptide's anti-inflammatory profile may accelerate recovery when combined with proper rehab.
Those Seeking Diagnostic GH Testing
If your doctor suspects growth hormone deficiency, pralmorelin is the gold-standard diagnostic tool in Japan and many countries. A single injection stimulates GH release, allowing physicians to assess your pituitary function safely and accurately.
Peptide Research Enthusiasts
Pralmorelin is one of the most extensively studied GHRPs worldwide. If you're exploring peptide protocols and understand research-grade products, this is a powerful tool for understanding how your GH axis responds to stimulation.
Athletes and Serious Trainers
If you're hitting the gym hard and want better recovery and muscle growth, GHRP-6 amplifies your body's natural GH response. This is particularly valuable during intense training phases when you want to maximize adaptation and minimize soreness. The appetite stimulation also helps you consume the calories you need to grow.
Those Exploring Novel Peptide Protocols
GHRP-6 offers a unique mechanism through the ghrelin receptor, making it valuable for users who want to explore diverse GH-stimulation pathways. It works distinctly from GHRH-based approaches and pairs well with other GH secretagogues for synergistic effects.
Longevity and Metabolic Health Enthusiasts
Growth hormone plays roles in metabolic health, body composition, and potentially aging markers. GHRP-6's emerging research on cellular protection and antioxidant activation makes it interesting for those interested in broader health optimization beyond just muscle growth.
Safety Profile
Sideeffects
Common
Facial flushing
Transient headache
Increased appetite
Temporary dizziness or lightheadedness
Uncommon
Carpal tunnel-like sensations
Joint or muscle aches
Sleep quality changes
Serious
Severe allergic reaction (anaphylaxis)
Increased Appetite
Mild Joint or Muscle Discomfort
Water Retention or Mild Swelling
Sleep Disturbances
Mild Dizziness or Lightheadedness
Allergic Reaction
Research Status
Safety& evidence
FDA Status
Research compound
Safety Overview
Pralmorelin (GHRP-2) has been safely used in diagnostic settings in Japan for decades and is well-tolerated in most individuals when used at appropriate doses. The peptide is synthetic and chemically stable, with low immunogenicity risk. However, it is NOT FDA approved and should only be used under medical supervision or within research protocols. Long-term safety data in healthy humans is limited.
Contraindications
xActive malignancy or unresolved cancer history
xUncontrolled hypertension or severe cardiovascular disease
xPregnancy or breastfeeding
xAcute infection or sepsis
xUncontrolled diabetes
GHRP-6 has a relatively long research history dating back to 1981, with human studies demonstrating its ability to stimulate GH release. The good news is that animal safety studies show excellent tolerability at high doses, and the side effects reported are generally mild and reversible. However, it's not FDA-approved, so use is based on research evidence rather than pharmaceutical oversight. Always purchase from reputable sources and consider medical consultation, especially if you have existing health conditions.
xKnown allergy or sensitivity to any component of the peptide
xActive cancer or history of cancer without medical clearance
xSevere cardiovascular disease or uncontrolled hypertension
xAcute critical illness or sepsis
Decision Guide
Which isright for you?
Choose Pralmorelin (GHRP-2) if...
Athletes seeking enhanced recovery and lean mass gains
Individuals with suspected GH deficiency (diagnostic use)
Recovery from tendon or bone injuries
Those wanting to test GH axis responsiveness
Choose GHRP-6 (Growth Hormone Releasing Peptide-6) if...
Building lean muscle mass and improving body composition
Recovery from intense training programs and athletic performance
Supporting overall metabolic health and longevity markers
Exploring novel GH-stimulation pathways for those who respond well to peptide protocols