GHRP-2
Also known as: GHRP-2 Acetate · Pralmorelin
A ghrelin-mimetic hexapeptide that produces a sharp GH pulse with only modest appetite stimulation. The balanced middle child of the GHRP family.
Overview
GHRP-2 sits between Ipamorelin (clean, weak) and GHRP-6 (dirty, hungry) on the secretagogue spectrum. The GH pulse it triggers is bigger than Ipamorelin's at equivalent doses, and the appetite bump is real but not the appetite avalanche GHRP-6 delivers. The catch is that it nudges cortisol and prolactin upward at the high end of the dose range, which is why most users stay at 100–200 mcg per dose rather than chasing 300 mcg three times daily. It is best deployed as the GHRP half of a GHRH+GHRP pairing — on its own the pulse is impressive but transient, and the body adapts within weeks.
Evidence quality
Small pharmacology trials in the late 1990s and early 2000s established that GHRP-2 produces a robust GH pulse in healthy adults and short children with idiopathic short stature. Pralmorelin (the same molecule under a different name) has been used as a diagnostic agent for GH deficiency in Japan. No large long-term efficacy or safety trials in healthy adults exist.
Benefits & timeline
Benefits
- Larger GH pulse than Ipamorelin at comparable doses — useful when you want amplitude, not just a clean signal
- Modest appetite increase, enough to support a bulking phase without being disruptive
- Pairs cleanly with GHRH analogues (Sermorelin, CJC-1295, Tesamorelin) for a synergistic pulse
- Cheaper per cycle than most alternatives in the secretagogue class
Timeline
Week 1
Sleep deepens within a few nights. Mild post-injection flush is normal.
Week 2
Appetite rises moderately; pumps in the gym start to feel fuller.
Week 4
Body composition shifts become measurable — recovery between sessions noticeably tighter.
Week 8
Pulse amplitude tapers as the receptor adapts. Time to hold dose, not escalate.
Week 12
Cycle off. Four weeks clear lets receptor sensitivity rebuild before the next run.
Dosage protocols
Advanced
300 mcg
thrice daily
Beginner
100 mcg
once daily
Standard
200 mcg
twice daily
Titration & adjustment
Start at 100 mcg once daily. After 1 week, split into 100 mcg AM + 100 mcg pre-bed if you want stronger GH coverage. Escalate to 200 mcg per dose at week 4 if appetite stimulation is desired. Maximum 300 mcg three times daily. Cycle off for 4 weeks every 12 weeks.
Injection timing
Best fasted — eat after the injection, not before. Pre-bed and post-workout are the two most common dose windows.
Side effects & contraindications
- mildFlushing in the first 30 seconds after subcut injection.
- mildIncreased appetite — usually a feature, sometimes a bug.
- moderateCortisol and prolactin creep at doses above 200 mcg per shot. Check labs if you run advanced doses for more than a month.
- moderateNo long-term human safety data outside the original pharmacology studies. The mechanism is well understood, but extended use is not.
Contraindications
- Active cancer or recent cancer history — GH-axis amplification is exactly the signal you do not want present
- Pregnancy or breastfeeding
- Pre-existing hyperprolactinaemia or prolactin-sensitive conditions
- Severe insulin resistance — GH pulses worsen the picture before they improve it
Reconstitution & injection
A 5 mg vial reconstituted with 2 ml of bacteriostatic water gives 2.5 mg/ml. A 100 mcg dose is 0.04 ml — 4 units on a U-100 insulin syringe. A 200 mcg dose is 8 units. Subcutaneous into abdomen or thigh, away from meals (fasted state matters because food blunts the pulse). Refrigerate after mixing; potency is reliable for about 4 weeks.
Open calculator pre-filledStorage after reconstitution
Refrigerate at 2–8 °C after reconstitution. Do not freeze. Light-protect. 28–30 days of stability in BAC water at fridge temperature.
Common mistakes
Running GHRP-2 alone and expecting CJC-1295-Ipamorelin-level results.
Better approach: A GHRP without a GHRH is half the protocol. The amplitude comes from pairing — GHRP-2 with Sermorelin or CJC-1295 produces a pulse that neither delivers alone. If cost is the reason to skip the GHRH, run Ipamorelin solo instead; the cleaner profile is more honest at half the protocol.
Dosing alongside meals because it is convenient.
Better approach: Food (especially carbs and protein) raises insulin and somatostatin, both of which blunt the GH pulse. Inject in a fasted window — most users land on pre-bed and AM-fasted as the two reliable slots. The extra 30 minutes of restraint is the difference between a real pulse and a wasted dose.
Escalating to 300 mcg three times daily because the bottle is sitting there.
Better approach: The dose-response curve flattens above 200 mcg per shot while cortisol and prolactin keep rising. The advanced protocol in the registry exists for a reason — competitive bodybuilders running stacks — but most users get 80% of the benefit at 100–200 mcg twice daily with a fraction of the side-effect creep.
Real-world tips
- Eat after, not before. The 30 minutes around injection should be water and patience.
- Pair pre-bed dosing with a hard training day for the strongest morning-after recovery signal.
- Track hunger as a feature, not just a side effect — if you are running a bulk, the appetite bump pays for itself in calories eaten.
- Check fasting cortisol once mid-cycle if you are running the standard or advanced protocol. Catch creep before it becomes a problem.
- Rotate injection sites between abdomen and thigh; the localised flush settles faster with rotation.
When something else is the better tool
Ipamorelin
Use instead when: You want a cleaner signal with negligible cortisol or prolactin movement and you are willing to accept a smaller pulse. Ipamorelin is the daily-driver choice for users who plan to run a secretagogue long-term.
GHRP-6
Use instead when: You specifically want the appetite stimulation as the primary effect — recovery from illness, hard gainer struggling to eat, or a deliberate mass phase. GHRP-2's hunger bump is mild by comparison.
Hexarelin
Use instead when: Short-burst, sharp-pulse use for a few weeks of pre-contest or performance work. Hexarelin hits harder but desensitises faster — GHRP-2 is the more sustainable choice for a full 12-week cycle.
- GHRP-2 or Ipamorelin?
- Bigger pulse, more side-effect creep, lower cost — that is the trade. If you are tracking labs and running a defined cycle, GHRP-2 gets you more amplitude per dollar. If you want set-and-forget for six months straight, Ipamorelin is the cleaner pick.
- Will the appetite bump derail a fat-loss phase?
- Probably not at 100 mcg twice daily. The hunger is noticeable but not commanding — much closer to the way you feel after skipping breakfast than the food-on-the-brain experience of GHRP-6.
- Do I need to stack it with a GHRH?
- You get a pulse without one, but it is roughly half the area-under-the-curve of a GHRP+GHRH pairing. Sermorelin is the cheapest add-on; CJC-1295 (no-DAC) is the most common.
- How long until I feel it working?
- Sleep usually deepens in the first few nights. Body composition takes 4–6 weeks to show meaningful shift. If nothing has changed by week 8, the protocol — not the molecule — is the variable to adjust.
- Is the flush dangerous?
- No. It is histamine release from the ghrelin receptor activation and settles within a minute. If it is persistent or accompanied by hives, drop the dose or switch to Ipamorelin.