GHRP-2 Dosage Guide: Protocols, Calculator & Safety
Everything you need to know about GHRP-2 dosing — protocols, safety, and where to buy.
Dose Range
100–300 mcg per injection
Frequency
1–3 times daily; bedtime injection most important
Cycle Length
8–12 weeks with 4-week breaks
Half-Life
~1 hour
Administration Routes
Quick Reconstitution Calculator
Calculate syringe units instantly
Syringe Draw
10.0 units
2500 mcg/ml · 0.100 ml draw
Dosing Protocols
Standard beginner protocol:
- Dose: 100 mcg subcutaneous per injection
- Frequency: 2-3x daily
- Timing: Empty-stomach windows — pre-breakfast, pre-training, pre-bed
- Duration: 12-16 weeks to assess response
Reconstitution: Typical vials are 5 mg lyophilized. Reconstitute with 2 mL bacteriostatic water for a 2.5 mg/mL concentration. A 100 mcg dose = 0.04 mL = 4 units on a U-100 insulin syringe.
Timing logic:
- Pre-breakfast (upon waking, fasted): Captures the natural morning GH pulse window before insulin rises from the first meal.
- Pre-training (30-45 min before workout, if trained fasted or 2+ hours post-meal): Amplifies training-induced GH release.
- Pre-bed (fasted, 30-60 min before sleep): Aligns with the dominant endogenous nocturnal GH pulse.
Why fasted: Elevated blood glucose and insulin blunt GH release through increased somatostatin tone. GHRP-2's potency is meaningfully reduced when dosed with or immediately after meals. Wait at least 2-3 hours after eating before dosing.
First-use considerations:
- Most users tolerate 100 mcg SC without appreciable nausea or flushing
- Some users experience mild head rush or warm flush in the first 5 minutes; this fades quickly
- Appetite increase will be noticeable within an hour — plan meals accordingly
- Expect vivid dreams with bedtime dosing
Labs to run before starting: IGF-1, fasting insulin, fasting glucose, HbA1c, basic metabolic panel, AM cortisol (if concerned about HPA status). Recheck at week 8 and week 16.
Optimized protocol for experienced users:
- Dose: 150-200 mcg SC per injection
- Frequency: 2-3x daily
- Timing: Pre-breakfast / pre-training / pre-bed (fasted)
- Stack: Typically combined with a GHRH analog for synergy
Standard GHRP-2 + GHRH stack:
- GHRP-2: 150-200 mcg SC
- Sermorelin: 200-300 mcg SC, OR
- CJC-1295 (no-DAC): 100-200 mcg SC
- Both drawn into the same insulin syringe and injected together
Why combine: GHRP-2 provides the ghrelin-pathway signal; GHRH analog provides the parallel GHRH-pathway signal. The intracellular convergence amplifies GH pulse amplitude 3-5x above either alone (Bowers 1991). This synergy is reliable across users and is the mechanistic foundation of classical peptide GH optimization protocols.
Cycling options:
- Continuous daily use: Straightforward. Monitor for receptor desensitization every 3 months via IGF-1 plateau detection.
- 5-on / 2-off weekly cycle: Weekends off to partially reset receptor sensitivity. Many practitioners prefer this for chronic use.
- 8-week-on / 2-week-off macro cycle: Full GHS-R1a reset every 2-3 months.
Progressive dosing:
Some users titrate gradually:
- Weeks 1-2: 100 mcg 2x daily
- Weeks 3-4: 100 mcg 3x daily
- Weeks 5-8: 150 mcg 3x daily
- Weeks 9+: 200 mcg 3x daily (if needed based on IGF-1 response)
Doses beyond 200 mcg per injection show diminishing returns due to GHS-R1a receptor saturation. Increasing frequency beyond 3x daily produces more consistent GH elevation but does not meaningfully increase total GH output.
Advanced protocol considerations:
Most advanced users transition from GHRP-2 monotherapy to either:
- GHRP-2 + GHRH combination (described above), or
- Switch to ipamorelin for cleaner long-term use
Situations where GHRP-2 is preferred over ipamorelin:
- Short-duration aggressive anabolic phase (8-12 weeks) where maximum GH pulse amplitude matters more than cortisol cleanliness
- Bulking / caloric surplus where the appetite stimulation is a feature not a bug
- Cost sensitivity — GHRP-2 is often less expensive per mg than ipamorelin
Situations where ipamorelin is preferred over GHRP-2:
- Chronic daily use beyond 3-4 months
- Cutting / caloric deficit where appetite stimulation is unwanted
- Users with baseline HPA axis concerns, anxiety, or prolactin issues
- Users prioritizing "clean" pharmacology over maximum GH pulse
Full performance stack example (8-12 week anabolic phase):
- GHRP-2: 200 mcg SC × 3 daily
- CJC-1295 no-DAC: 100 mcg SC × 3 daily (paired with each GHRP-2 injection)
- BPC-157: 500 mcg SC × 2 daily (for connective tissue and training recovery)
- TB-500: 2 mg SC × 2 weekly (soft tissue remodeling)
Combinations to manage:
- With testosterone replacement: Well-established anabolic synergy; additive body composition effects
- With GLP-1 agonists (semaglutide, tirzepatide): GHRP-2's appetite stimulation partially antagonizes the GLP-1 appetite suppression. Use either the minimum GHRP-2 dose needed or consider ipamorelin instead
Combinations to avoid:
- GHRP-2 + GHRP-6: Mechanistically redundant; both GHS-R1a agonists. No additional benefit.
- GHRP-2 + Hexarelin: Same class; redundant. Also, hexarelin has more pronounced cortisol and prolactin effects.
- GHRP-2 + MK-677: Redundant for GHS-pathway purposes. If 24-hour coverage is the goal, MK-677 alone is simpler.
- GHRP-2 + exogenous HGH: Pointless — exogenous GH suppresses endogenous pituitary output via IGF-1 negative feedback, rendering GHRP-2 functionally inert.
Discontinuation triggers: Persistent joint pain, peripheral edema, carpal tunnel symptoms, elevated fasting glucose (>110 mg/dL persistently), or any cardiovascular symptoms.
Weight-Based Dosing
Commonly Stacked With
Synergistic Combinations
GHRP-2 + GHRH analog (sermorelin, CJC-1295 no-DAC, or tesamorelin): The foundational synergistic pairing. GH pulse amplitude amplified 3-5x vs either alone (Bowers 1991). Inject simultaneously SC, 2-3x daily, fasted.
GHRP-2 + BPC-157 / TB-500: Complementary for training intensification. GHRP-2 drives systemic anabolism; BPC-157 and TB-500 drive connective tissue and soft-tissue healing. Standard in peptide-assisted recovery from hard training or injury.
GHRP-2 + Testosterone optimization: Additive anabolic effects. Well-established clinical synergy in hypogonadal men with GH-axis decline.
Situational
GHRP-2 + Semaglutide/Tirzepatide: Opposing appetite signals. GHRP-2 stimulates hunger (ghrelin-receptor agonism); GLP-1 agonists suppress it. In users who want both lean-mass preservation during a GLP-1 deficit phase, keeping GHRP-2 dose minimal (50-100 mcg) preserves GH stimulus without significantly antagonizing the GLP-1 appetite effect. Consider ipamorelin as the cleaner choice here.
GHRP-2 + NAD+: Non-interfering, complementary for longevity-focused protocols. NAD+ supports mitochondrial function; GHRP-2 supports GH/IGF-1 axis. Different pathways.
Redundant (Avoid or Reconsider)
GHRP-2 + GHRP-6: Same mechanism class (GHS-R1a). No synergistic benefit; GHRP-6 has higher appetite-stimulating effect which may or may not be desired.
GHRP-2 + Hexarelin: Same class. Hexarelin has more pronounced cortisol and prolactin elevation — combining stacks the unwanted cross-effects without additive GH benefit.
GHRP-2 + MK-677: Both GHS-R1a agonists. MK-677 provides 24-hour receptor occupancy; adding short-pulse GHRP-2 produces diminishing returns. Choose one.
GHRP-2 + Ipamorelin: Same class. Ipamorelin is mechanistically a cleaner version of GHRP-2 — pick one based on whether maximum pulse or clean profile matters more.
Avoid
GHRP-2 + exogenous recombinant HGH: Pharmacologically counterproductive. Exogenous GH suppresses endogenous GHRH and somatotroph activity via IGF-1 negative feedback. GHRP-2 is rendered functionally inert.
GHRP-2 + aggressive glucocorticoid therapy: GH-axis stimulation is less effective under pharmacologic steroid context, and both agents can additively affect glucose homeostasis.
Related Compound Pages
- Ipamorelin — Cleaner GHS-R1a agonist alternative
- GHRP-6 — Earlier-generation GHS with stronger appetite effect
- Hexarelin — More potent GHS with more cortisol elevation
- CJC-1295 — GHRH analog synergy partner
- Sermorelin — Pulsatile GHRH synergy partner
- Tesamorelin — FDA-approved GHRH analog
- MK-677 — Oral long-acting GHS alternative
- BPC-157 — Tissue repair stack partner
- TB-500 — Soft tissue remodeling stack partner
- NAD+ — Mitochondrial longevity stack partner
- Epithalon — Pineal/telomere support
Side Effects & Safety
Contraindications
GHRP-2 is contraindicated or requires caution in: - **Active malignancy** — particularly hormone-responsive cancers (breast, prostate); elevated IGF-1 may promote tumor growth - **Strong family history of GH-axis sensitive cancers** — specialist supervision required - **Pregnancy and lactation** — no established safety data; avoid - **Known hypersensitivity** to GHRP-2, related hexapeptides, or any excipient - **Severe untreated obstructive sleep apnea** — theoretical airway soft-tissue concern - **Acute critical illness** — GH-axis stimulation inappropriate during sepsis, post-surgical recovery, multiple trauma, respiratory failure - **Diabetic ketoacidosis or severe uncontrolled diabetes** — resolve metabolic state first - **Active proliferative retinopathy** — relative contraindication - **Hypothalamic-pituitary disease with adrenal insufficiency** — the residual cortisol effect may be unreliable; specialist supervision required - **Prolactinoma or hyperprolactinemia** — the modest prolactin elevation could complicate management **Relative cautions (monitor closely):** - Borderline fasting glucose or HbA1c — GH-axis effects can tip toward insulin resistance - Cushing's syndrome or baseline elevated cortisol — GHRP-2 adds to HPA axis load - Anxiety or HPA axis dysregulation — the cortisol elevation, while modest, may be poorly tolerated - Strong family history of colon polyps — baseline colonoscopy before starting, surveillance per GI guidelines - Concurrent glucocorticoid therapy — GH-axis stimulation is less effective under pharmacologic steroid **Drug interactions:** - **Glucocorticoids:** Pharmacodynamic interference; reduced GH response - **Opiates/opioids:** Can augment the cortisol and prolactin effects of GHRP-2; monitor - **Thyroid hormone replacement:** GH-axis changes can modify thyroid needs; monitor TSH if using chronically - **Exogenous GH:** Pharmacologically counterproductive; the combination is pointless **Discontinuation triggers:** - Persistent joint pain, carpal tunnel symptoms, or peripheral edema (suggesting IGF-1 is too high) - Persistent fasting glucose elevation beyond 110 mg/dL - Any signs of cushingoid body composition change (buffalo hump, moon face, central obesity beyond baseline) - Worsening sleep apnea - New or changing pigmented lesions (unrelated to GHRP-2 but always a stop-and-evaluate signal in any peptide protocol) - Any cardiovascular symptoms
Additional Notes
Standard Dosing Reference
| User Tier | Per Injection | Frequency | Daily Total |
|---|---|---|---|
| Beginner | 100 mcg | 2x/day | 200 mcg |
| Intermediate | 100-150 mcg | 3x/day | 300-450 mcg |
| Advanced | 150-200 mcg | 3x/day | 450-600 mcg |
| Diagnostic IV (Japan) | 0.3-1 mcg/kg | Single bolus | — |
Rules
- Fasted dosing — at least 2-3 hours after last meal, as elevated glucose/insulin blunts GH release
- Pre-activity timing — pre-breakfast, pre-training, pre-bed are the optimal windows
- Subcutaneous route — IV route reserved for diagnostic testing
- Consistent timing — GH axis entrains to regular schedules; variability reduces effectiveness
- Single-injection ceiling: ~300 mcg — above this, receptor saturation prevents additional GH release
Concentration and Volume
Standard 5 mg vial + 2 mL BAC water = 2.5 mg/mL:
- 100 mcg = 0.04 mL = 4 units on U-100 insulin syringe
- 150 mcg = 0.06 mL = 6 units
- 200 mcg = 0.08 mL = 8 units
- 300 mcg = 0.12 mL = 12 units
Monitoring
- Baseline: IGF-1, fasting insulin, fasting glucose, HbA1c, AM cortisol, prolactin (if using long-term)
- Week 8: Recheck IGF-1 and fasting glucose
- Week 16: Full panel including cortisol and prolactin
- Every 3 months thereafter: IGF-1 + fasting glucose
- Every 6 months: Full panel
Target IGF-1: Upper quartile of age-adjusted reference range. Not supraphysiologic.
When Not to Dose
- Within 2-3 hours of a meal (reduced efficacy)
- During acute illness with fever
- If fasting glucose is persistently above 110 mg/dL — address metabolic state first
- If current cortisol levels are elevated or under clinical investigation
Storage
- Lyophilized: refrigerated 2-8°C, stable up to 2 years sealed
- Reconstituted: refrigerated 2-8°C, use within 30 days
- Never freeze reconstituted peptide
- Protect from light
Where to Buy GHRP-2
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Frequently Asked Questions
What is the recommended GHRP-2 dosage?
The typical dose range for GHRP-2 is 100–300 mcg per injection. It is usually administered 1–3 times daily; bedtime injection most important. Always start with the lowest effective dose.
How often should I take GHRP-2?
1–3 times daily; bedtime injection most important
Does GHRP-2 need to be cycled?
Yes, typical cycle length is 8–12 weeks with 4-week breaks.
What are GHRP-2 side effects?
## Common (dose-dependent) - **Increased appetite / hunger** — GHRP-2 is a ghrelin-receptor agonist, and ghrelin is the body's primary hunger signal. Expect measurable appetite stimulation starting ~30 minutes post-injection and peaking at 1-2 hours. Beneficial in caloric surplus phases; problematic in deficit phases. - **Transient cortisol elevation** — +15-25% above baseline in the 60-90 min post-injection window. Usually clinically trivial in healthy users but relevant in users with HPA axis dysregulation, adrenal insufficiency, or stress-driven cortisol issues. - **Modest prolactin elevation** — usually not clinically meaningful but relevant in users with baseline prolactin concerns or prolactin-sensitive pathologies. - **Injection site reactions** — mild erythema or transient itching at SC site; site rotation minimizes. - **Flushing** — warm, pink flush in face/neck post-injection, fading within 15-30 minutes. ## Less Common - **Mild fluid retention** — particularly in first 2-3 weeks of daily use; usually self-limiting. - **Vivid dreams** — secondary to improved slow-wave sleep when dosed at bedtime. - **Transient insulin sensitivity reduction** — GH-axis stimulation modestly reduces insulin sensitivity; monitor HbA1c and fasting glucose in extended use. - **Headache** — mild, typically responsive to hydration. - **Nausea** — uncommon at SC doses; more common with high IV boluses. ## Rare - **Significant hypotension** — primarily with IV administration; SC route rarely produces meaningful BP effects. - **Hypersensitivity reactions** — rare local or systemic allergic response. - **Paresthesia or scalp tingling** — transient, benign. - **Dysgeusia** — metallic or unusual taste immediately post-injection. ## Cumulative with Long-term Use - **Insulin resistance** — sustained daily dosing over months can modestly reduce insulin sensitivity. Monitor HbA1c and fasting insulin quarterly. - **Receptor desensitization** — unlike GHRH analogs which retain pituitary responsiveness well, chronic high-dose GHS can produce measurable GHS-R1a tachyphylaxis. Cycling protocols (5 on / 2 off, or 8 weeks on / 2 weeks off) help maintain responsiveness. - **HPA axis adaptation** — persistent low-grade cortisol elevation over months could theoretically contribute to HPA dysregulation in susceptible users. Periodic ACTH/cortisol monitoring in chronic protocols is sensible. ## Theoretical Long-term Concerns As with all GH-axis interventions, the IGF-1 elevation produced by GHRP-2 raises a theoretical concern around chronic supraphysiologic mitogenic signaling and cancer risk. No causal link has been demonstrated in trials, but mechanistic plausibility supports conservative dosing, periodic IGF-1 monitoring, and avoidance in users with active malignancy or strong family history of hormonally-responsive cancers. ## Signs You Are Overdosing - Persistent joint discomfort or peripheral edema - Carpal tunnel-like symptoms - Persistent elevated fasting glucose - Unexpected weight gain beyond what caloric intake accounts for - Sleep apnea worsening Any of these warrant dose reduction or discontinuation.
Where can I buy GHRP-2?
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