GHRP-2 is a synthetic peptide that stimulates the release of growth hormone by activating ghrelin receptors. It is typically administered via subcutaneous injection, usually once daily, to encourage robust, pulsatile GH release while avoiding receptor desensitization. The dosing often involves a gradual increase over several weeks.
- Potently stimulates growth hormone release.
- Administered once daily to prevent receptor desensitization.
- Typical dose ranges from 100-300 mcg daily.
- Reconstitution with 3.0 mL bacteriostatic water yields 1.67 mg/mL.
- Cycle lengths commonly range from 8 to 16 weeks.
Reconstitution
Vial strength
5 mg
Bacteriostatic water
3 mL
Concentration
1.67 mg/mL
1 unit = 0.01 mL = 16.7 mcg
- 1Draw 3.0 mL of bacteriostatic water using a sterile syringe.
- 2Inject the water slowly down the inside wall of the GHRP-2 vial, being careful to avoid creating foam.
- 3Gently swirl or roll the vial until the powder is fully dissolved, but do not shake it.
- 4Label the reconstituted vial and store it in the refrigerator at 2–8 °C (35.6–46.4 °F), protected from light.
Dosing schedule
| Phase | Dose | On a U-100 syringe |
|---|---|---|
| Weeks 1-2 | 100 mcg | 6 units (0.06 mL) |
| Weeks 3-4 | 150 mcg | 9 units (0.09 mL) |
| Weeks 5-8 | 200 mcg | 12 units (0.12 mL) |
| Weeks 9-16 | 200 mcg | 12 units (0.12 mL) |
Protocol detail
| Start | Begin with 100 mcg daily for the first 1-2 weeks. This initial dose effectively stimulates GH and allows for assessment of tolerance. |
|---|---|
| Mid-level | Increase to 150 mcg daily for Weeks 3-4 to further enhance the growth hormone response, assuming the initial dose was well tolerated. |
| Target | Aim for 200 mcg daily from Weeks 5-16. This dose is typically effective for producing maximal effects in most research contexts. Experienced researchers might consider increasing to 250–300 mcg. |
| Frequency | Inject once per day subcutaneously. Evening administration may align better with the body's natural nocturnal GH release rhythms. |
| Cycle Length | Protocols generally last 8 to 16 weeks. While some initial response attenuation might occur in the first couple of weeks, the response typically stabilizes with continuous dosing. |
Overview at a glance
| Goal | To stimulate the body's natural growth hormone secretion by activating ghrelin receptors. |
|---|---|
| Schedule | Daily subcutaneous injections for an initial period of 8–12 weeks, with an option to extend to 16 weeks. |
| Dose Range | An increasing dose from 100 to 300 mcg daily. Higher doses are possible but may not offer much additional benefit for routine use. |
| Reconstitution | Use 3.0 mL of bacteriostatic water per 5 mg vial, resulting in a concentration of approximately 1.67 mg/mL for precise unit measurements. |
| Storage | Lyophilized powder should be kept frozen. Once reconstituted, store in the refrigerator and use within 2–3 weeks for best results. |
How it works
GHRP-2 functions as a growth hormone secretagogue, meaning it stimulates the pituitary gland to release growth hormone. It achieves this by binding to and activating the ghrelin receptors in the body. This activation leads to a powerful, pulsatile release of GH in a dose-dependent manner. Clinical studies have shown significant increases in GH, even at lower doses, with sustained efficacy seen over several months in GH-deficient children. In healthy adults, daily doses of 100-300 mcg subcutaneously acutely stimulate GH, balancing effectiveness with maintaining receptor sensitivity. The peptide has generally been well-tolerated in clinical trials, with no significant adverse effects reported at these ranges.
Reported effects
- Stimulates robust pulsatile growth hormone release.
- May support positive changes in body composition.
- Can improve metabolic health.
- Enhances IGF-1 levels when combined with therapies like GHRH analogs.
- Well-tolerated with a safety profile similar to placebo.
Reported side effects
- Mild temporary hunger sensation.
- Occasional flushing.
- Mild injection site reactions (redness, irritation).
- Potential for slight attenuation with very frequent dosing.
Storage
Lyophilised (unmixed)
Store at -20 °C (-4 °F) in dry, dark conditions; powder is stable at room temperature for short periods, but freezer storage maximizes shelf life.
After reconstitution
Refrigerate at 2–8 °C (35.6–46.4 °F); use within 2–3 weeks for optimal integrity. For longer storage, consider aliquoting and freezing at -20 °C (-4 °F) with a carrier protein, avoiding repeated freeze-thaw cycles. Always protect from light and heat.
Supplies
| Peptide vials | Approximately 2-5 vials of GHRP-2 (5 mg each) are needed for 8-16 weeks. |
|---|---|
| Insulin Syringes (U-100) | 56-112 syringes for 8-16 weeks, using one per day. Consider 30- or 50-unit syringes for doses under 10 units for better readability. |
| Bacteriostatic Water | 1-2 bottles (10 mL each) to reconstitute the peptide vials throughout the cycle. |
| Alcohol Swabs | 2-3 boxes (100-count each) for sterilizing vial stoppers and injection sites. |
Important notes
- Always use a new, sterile insulin syringe for each injection and dispose of it in a sharps container.
- Rotate injection sites (abdomen, thighs, upper arms) to minimize local skin irritation and prevent lipodystrophy.
- Frequent dosing (e.g., every 2 hours) can lead to acute tachyphylaxis and reduced effectiveness; once-daily administration avoids this.
- Document daily doses and injection site rotation to ensure consistency throughout the protocol.
- This information is for educational and research purposes only and not medical advice.
Frequently asked questions
What is the best time of day to inject GHRP-2?
Injecting GHRP-2 in the evening is often recommended. This timing can align with the body's natural nocturnal growth hormone release rhythms, potentially enhancing its effectiveness.
How precise do I need to be with the reconstitution water volume?
It's important to be as precise as possible with the 3.0 mL of bacteriostatic water. This ensures the correct concentration of 1.67 mg/mL, making it easier to accurately measure doses using an insulin syringe.
What if I miss a dose of GHRP-2?
If you miss a dose, simply resume your regular schedule the next day. Do not take a double dose to compensate, as this could lead to unnecessary side effects or reduced efficacy due to receptor desensitization.
Can I use GHRP-2 with other peptides?
GHRP-2 is often combined with other peptides, particularly GHRH analogs like CJC-1295, to create a synergistic effect that significantly boosts growth hormone and IGF-1 levels. However, any combination should be researched thoroughly.
Educational reference only. These figures summarise how GHRP-2 is commonly described in research literature and supplier documentation, including the GHRP-2 listing at peptidesuk4u.co.uk. They are not a prescription, not medical advice, and not a recommendation to self-administer anything.
Related protocols
GHRP-2 (10 mg Vial)
Potent growth hormone secretagogue mimicking ghrelin's action.
CJC-1295 DAC (2 mg Vial)
Long-acting GHRH analog for sustained growth hormone release.
GHRP-6 (10 mg Vial)
Mimics ghrelin to stimulate growth hormone release.
GHRP-6 (2 mg Vial)
Stimulates GH release for muscle growth, fat loss, and recovery.