STUDresearch · Peptide
GHRP-2
Also known as
Pralmorelin · Pralmorelin hydrochloride · KP-102 · KP-102LN · GPA 748 · GPA-748 · WAY-GPA-748 · GHRP Kaken 100 · Growth hormone-releasing peptide-2 · GHRP2 · GHRP 2 · D-Ala-D-2Nal-Ala-Trp-D-Phe-Lys-NH2
Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.
Peptide
Lots of talk
Systemic
Subcutaneous; IV studies and other routes discussed separately
Growth hormone axis
Systemic — ghrelin-receptor agonist discussed for pituitary GH pulses, appetite, recovery and body composition; not local joint or muscle targeting.
What people say
GHRP-2, also called pralmorelin, is a ghrelin-receptor peptide discussed for GH pulses, appetite and recovery. Clinical GH-testing research does not validate repeated bodybuilding use.
Doses people talk about
Reported amounts, not recommendations. Route, population, formulation and frequency differ between these accounts.
How it may feel
People describe hunger, warmth, flushing, lightheadedness or drowsiness. Sleep and recovery changes are reported too; multi-week body-composition claims are often entangled with training, food intake and other compounds.
Community charts100–300 mcg subcutaneously per administration; one to three daily administrations discussed
Research-chemical/forum schedules, not amounts validated by large body-composition trials.
Weight-based “saturation” talk1–2 mcg/kg per reported pulse
Route varies across summaries; roughly 100–200 mcg for many adults is commonly quoted. Diminishing-return and secondary-hormone claims do not establish a safe target.
Pediatric IV study1 mcg/kg once intravenously
Ten prepubertal children in the parent-peptide PK study. Separate older 100 mcg and 200 mcg descriptions are not interchangeable with this exposure.
Half-life & effect duration
- Half-life in the body
- IV study · childrenAbout 33 minutes
- Community / secondary estimatesAbout 15–30 minutes or 25–40 minutes; broader summaries give 15–60 minutes
- Felt duration people report
- Hunger waveAbout 20 minutes in one combination-use account
Cycles people discuss
Charts discuss 4–6-week trials of use or 8–16-week runs, with 8–12 weeks frequently repeated. Some describe 5 days on/2 off or 4–8 weeks off. These are community calendars, not validated diagnostic-study schedules.
Timing
Charts describe morning fasted and/or bedtime use, about 2+ hours after food and a 20–30-minute wait before carbohydrates. Hunger versus that wait is a recurring debate; these are reported practices, not a universal timing rule.
Stacks
Classic dual pulse: GHRP-2 + CJC-1295 no-DAC / Mod GRF 1-29 — default synergistic GHRH + GHRP stack; often ~100–200 mcg each same syringe.
Access talk
2026 shelves: leftover clinic vials, telehealth “GH peptide” blends that may still say GHRP-2, and RUO lyophilized vials. A Category 3 nomination is not permission to compound.
Labs people mention
IGF-1 is what people recheck to see if the axis moved. Solo GHRP-2 pulses often nudge morning trough IGF-1 less than DAC-CJC or somatropin IU charts.
Watch for
503B SAE language is not gym folklore: FDA’s injectable/nasal GHRP-2 note includes infection, pancreatitis, and deaths in critically ill study subjects — causality not established, still the compounding-risk text people quote in 2026.
Tap a line to jump into the full notes. Research only — may be wrong.
Timing context & sources
Half-life in the body
About 33 minutes in one intravenous study in children.
This is GHRP-2 in blood—not the duration of hunger or the released GH response. Adult subcutaneous timing is not established by this study.
The original abstract reports 0.55 ± 0.14 hours in ten children, mean age 7.7 years. Its separate GH half-life and peak are different endpoints. Full methods were not reviewed; no adult-SC or repeated-use equivalence is claimed.
- Pihoker et al. (1998): GHRP-2 pharmacokinetics in children (opens in a new tab)Abstract paragraphs 2–4: ten children, IV route, parent t½ 0.55 ± 0.14 h versus separately measured GH kinetics.Original abstract reviewed, not full paper. Pediatric single-dose IV study; not adult subcutaneous use.
Felt duration people report
One person describes a hunger wave lasting about 20 minutes—sometimes gone by the time a meal was cooked.
That is a reported duration, not time to onset or a measured GH pulse. The account covers three weeks of use with another compound.
The thread title discusses GHRP-6, but the adopted commenter explicitly identifies GHRP-2. This is one unverified account, not a typical duration or a comparison trial. The community links commercial supplier guides; those guides and injection advice are not adopted.
- GHRP-2 hunger reports in a BodyHackGuide discussion (opens in a new tab)Unhappy-Product-1526: comments identifying GHRP-2, hunger gone while cooking, and hunger lasting about 20 minutes after three weeks of GHRP-2 plus GHK-Cu.First-person comments reviewed. GHRP-6 is the OP's topic, not the adopted commenter's compound. Unverified product, co-use and commercial community context.
What people say
- Hard-gainer bulk: Moderate hunger often treated as a deliberate calorie-boost feature without GHRP-6-level “ravenous” wrecking of cuts. forum
- Recovery logs: Easier session-to-session bounce-back and less next-day soreness claims over multi-week runs — usually stack- and training-confounded. forum
- Sleep / night dose: Bedtime empty-stomach + optional GHRH partner heavily linked to deeper sleep, vivid dreams, and “night recovery” talk. forum
- Vs GHRP-6: Forums rank GHRP-2 higher peak GH and milder hunger/cortisol/prolactin chatter than GHRP-6. forum
- Vs ipamorelin: Stronger absolute GH-pulse lore; kept when users want more “punch” and can accept mild cortisol/prolactin/appetite tradeoffs. forum
- Vs hexarelin: Similar strong GH class; hexarelin often cast as more aggressive on prolactin/cortisol and desensitization fear. forum
- GHRH synergy credit: Most physique wins credited to GHRP-2 + GHRH (Mod GRF / CJC no-DAC / sermorelin) dual pulse, not GHRP-2 monotherapy. forum
- IGF-1 proxy: Some multi-week logs track morning IGF-1 as a crude “axis engaged” check; acute GH spike ≠ automatic weekly recomp. forum
- Skin / fullness: Mild “GH look” fullness or skin-quality notes appear; water retention can mimic the same look. anecdote
- Acute GH pulse: Strong, dose-dependent GH rise after each dose; secondary writeups often cite peaks on the order of ~30–100 ng/mL within ~15–30 min depending on dose/route/individual. trial
- Stronger than max GHRH alone: Arvat et al. 1997 — 1 mcg/kg IV GHRP-2 produced GH responses higher than 1 mcg/kg GHRH in young adults; 2 mcg/kg higher still vs 1 mcg/kg. trial
- Appetite (trial): Laferrère et al. — continuous SC infusion raised ad libitum food intake ~30–36% vs placebo in lean men at 1 μg/kg/h; dose-dependent ~10% (low dose) to ~34% (high dose) in lean/obese crossover work. trial
- Diagnostic reliability: Japanese pralmorelin test — healthy subjects typically exceed ~15 mcg/L plasma GH after a standard provocative dose; severe GHD stays below — basis of approved diagnostic use. trial
- Pediatric growth signal: Mericq/Bowers-style multi-month SC dosing in GH-deficient children showed dose-dependent overnight episodic GH and higher growth velocity during treatment vs pre/post periods (small N; not a gym protocol). trial
Doses people talk about
- Per-injection band: ~100–300 mcg subcutaneous per administration is the near-universal modern research-chem / forum range. forum
- Diagnostic and research amounts: Older diagnostic summaries mention ~100 mcg and pair it with ~1 mcg/kg; that is not a universal conversion between absolute and weight-based amounts. Separate GH-dynamics writeups mention ~200 mcg (~2–3 mcg/kg class). Pihoker’s ten-child PK study used a single 1 mcg/kg IV administration. Community charts map clinical numbers onto subcutaneous multi-daily use, but those routes, populations and schedules are not equivalent. trialforum
- Beginner template (community): ~100 mcg once daily before bed, empty stomach, often 8–12 weeks to test sleep/hunger response. forum
- Intermediate template: ~150–200 mcg, 2× daily (AM fasted + bedtime), empty stomach. forum
- Aggressive template: ~200–300 mcg, 2–3× daily (AM fasted, post-workout or midday, bedtime); hunger and spillover sides rise with dose and frequency. forum
- Bedtime-only: ~100–200 mcg once nightly remains popular when users want one pulse aligned with nocturnal GH. forum
- Frequency spacing: Pulses spaced hours apart (commonly ≥~3 hours in protocol sheets) because each shot is an acute pulse, not a depot. forum
- With GHRH partner (same pulse): Commonly discussed as GHRP-2 ~100–200 mcg + Mod GRF / CJC no-DAC ~100–200 mcg co-injected; do not double GHRP-2 just because it is stacked. forum
- Two-GHRP stacks discouraged: Combining GHRP-2 + ipamorelin (same receptor class) is generally framed as non-synergistic vs pairing one GHRP with a GHRH analog. forum
- Food timing: Empty stomach — commonly ≥~2 hours after a meal (esp. carbs) and ~30–60 min before eating; elevated glucose/insulin widely said to blunt the GH pulse. forum
- Post-shot eat delay: Many guides say wait ~20–30+ minutes after injection before carbs/protein; some push longer if maximizing the pulse is the goal. forum
- Purity / fill flag: Without third-party testing, labeled mcg may not equal delivered peptide; under/over-fill and mislabel are structural gray-market risks. forum
- 2026 ranking sheets: Ipamorelin 100–300 mcg as the “clean” once-daily GHRP; GHRP-2 still 100–300 mcg per shot, often 2–3×/day when people want more pulse and will take hunger/cortisol. forum
- Saturation still ~1–2 mcg/kg: Climbing past ~200–300 mcg/pulse is framed as more PRL/cortisol/hunger, not a bigger GH peak. forum
- Daily totals discussed: Roughly ~200–900 mcg/day appears in multi-dose summaries, alongside the separate ~100 mcg once-daily chart. Charts describe 1–3 shots at ~100–300 mcg each; the quoted 200–900 range is not exhaustive. Older clinic-adjacent notes sometimes cite ~100–500 mcg/day injectable GHRP-class totals with higher stacked ceilings next to sermorelin — those are not standardized gym RCTs. forum
- Clinical-aligned “saturation” talk: ~1–2 mcg/kg per pulse (~100–200 mcg for many adults) is repeatedly named as the diminishing-returns GH band; past ~2 mcg/kg, extra GH plateaus while sides (cortisol/prolactin/hunger) can still climb. trial
- Framing: Discussed research and community ranges only — not medical advice, not prescriptions, not safety-validated bodybuilding protocols. forum
How it may feel
- First 15–60 min: Hunger wave often peaks ~20–30 min post-shot; minority report flush, warmth, lightheaded rush, or mild drowsiness (especially pre-bed). forum
- Days 1–7: Appetite is the most consistent early effect; sleep depth/vivid dreams common when night dose is timed empty-stomach. forum
- Weeks 1–2: Hunger, mild water/fullness, and recovery “ease” usually appear before clear recomp or fat-loss claims. forum
- Weeks 3–4: Checkpoint for hunger control, edema, libido/mood (prolactin talk), fasting glucose curiosity, and whether to add/fix a GHRH partner. forum
- Weeks 6–8: Body-composition and recovery anecdotes thicken in bulk logs; cutters often still fighting appetite or drop dose frequency. forum
- Weeks 10–16: Longer aggressive multi-pulse runs claim more cumulative size/recovery; receptor-sensitivity and cost push cycling talk. forum
- No change by ~4 weeks: Forum replies discuss empty-stomach timing, sleep, calories, product purity and a GHRH partner when no change is noticed around four weeks. These are proposed explanations, not established diagnoses or justification for increasing beyond “saturation” lore. forum
- If hunger is the only signal: 2025–26 logs treat a missing hunger wave as a product/timing check, not automatic proof the GH pulse happened. forum
- Switch talk: Moving to ipamorelin when cortisol/PRL/hunger wins is the usual 2026 exit, not a dose spike. forum
- Hours 1–3: Acute GH elevation window discussed as mostly over within a few hours — not all-day elevation like MK-677. trial
Around the dose
- Clock: AM fasted and/or bedtime empty-stomach. 2026 charts still copy 1–3 pulses, not a weekly depot. forum
- Food-timing lore: Community charts describe ~2+ hours after food and ~20–30 minutes before carbohydrates, repeating the insulin-blunts-the-GH-pulse explanation also discussed for ipamorelin. These are attributed timing practices, not a universal administration rule. forum
- Hunger wave: Reports often call hunger moderate relative to GHRP-6, but strong enough to disrupt a planned calorie deficit; others choose ipamorelin to avoid that tradeoff. forum
- Training context: Posts describe night or morning use with lifting during the day, treating GHRP-2 as a systemic GH-axis peptide rather than an acute gym-bag pump product. This describes community scheduling, not an injection or training instruction. forum
- After-dose debate: Forum discussion weighs the reported hunger wave against claims that eating soon after administration blunts the GH pulse; no universal timing rule was established here. forum
- Partner: Same-syringe GHRH (CJC no-DAC / Mod GRF / sermorelin) is the 2026 stack; two GHRPs in one day is still called redundant. forum
Cycles people discuss
- Common physique block: 8–12 weeks on is the most repeated community template for recovery/bulk-oriented runs. forum
- Longer aggressive block: 8–16 weeks on appears in “advanced” multi-pulse + GHRH writeups. forum
- Shorter probe: 4–6 weeks to test hunger tolerance, sleep response, and whether the product feels active. forum
- Time off: Often ~4–8 weeks off after multi-month on (some community charts say ~8 on / 8 off) for cost, IGF-1/HPA “normalize” folklore, and receptor-sensitivity talk — not a single standardized trial schedule. forum
- 5-on / 2-off: Older and still-common minority weekly pattern; some sources cite consecutive-day response attenuation in GHRP literature as rationale. forum
- Daily multi-dose modern logs: Many current users run every day at 2–3× without weekend off; comparative superiority is anecdotal. forum
- No loading phase: Protocols describe flat mcg from day one (or slow titration for sides), not a load/maintain split. forum
- Re-runs: Common around bulk phases, hard camps, or when users switch back from ipamorelin for more appetite drive. forum
- Long-term open-ended use: Discussed in longevity-adjacent talk but long-horizon safety data for healthy multi-daily self-experimenters is thin. forum
Timing
- Parent half-life versus older summaries: Older guides quote ~15–30 minutes, sometimes ~25–40 minutes labeled IV elimination, with a broader secondary range of ~15–60 minutes. These summaries do not establish a general adult subcutaneous clock. Pihoker’s study measured mean parent-peptide terminal half-life of 0.55 ± 0.14 hours (about 33 minutes) after one 1 mcg/kg IV administration in ten prepubertal children. Released-GH kinetics and hunger duration are separate endpoints; this is short-pulse discussion, not a weekly depot. trialforum
- Multi-daily discussion: Community charts describe 1–3 timed pulses (AM / peri-workout / night) rather than one weekly shot. This is reported scheduling logic, not validation of a frequency from a pharmacokinetic measurement. forum
- IGF-1 lag: Acute GH spike ≠ weeks of IGF-1 or recomp claims; few users run serial labs, so physique credit is soft. forum
- Food blunt: Recent carbs / high glucose / free fatty acids said to blunt the GH pulse — empty-stomach ritual is nearly universal in community protocols. forum
- Desensitization lore: Consecutive multi-day GHRP exposure attenuation is discussed from older secretagogue literature and drives 5-on/2-off or multi-week off blocks more than a GHRP-2-specific large RCT. forum
- Vs MK-677: Short injectable pulses vs long oral ghrelin-mimetic elevation with day-long hunger/water/glucose talk. forum
- Vs CJC with DAC: Pairing with long-acting GHRH changes IGF-1 time course, but GHRP-2 itself stays short-acting — pulse timing still matters. forum
- Peak GH timing: Frequently ~15–30 min post-administration in clinical summaries; elevated GH often discussed as lasting ~2–3 hours before returning toward baseline. trial
- GHRH co-admin synergy: Human endocrine work and secondary summaries describe combined GHRP + GHRH responses multiples of either alone (writeups often cite ~2–3× to several-fold; some community sources stretch to ~3–10×) via distinct receptor pathways (GHS-R1a vs GHRHR). trial
More on what it is
- Why people search it: Long-standing high-volume GHRP in bodybuilding/peptide forums — stronger GH-pulse talk than GHRP-6 or ipamorelin, with moderate (not extreme) hunger. forum
- Mechanism talk: Ghrelin-mimetic short pulse; preserves somatostatin feedback so it amplifies pulses rather than acting like a continuous GH depot. forum
- What it is: Synthetic hexapeptide GH secretagogue (pralmorelin / KP-102; sequence commonly written D-Ala-D-2Nal-Ala-Trp-D-Phe-Lys-NH2; ~818 Da; CAS 158861-67-7) that pulses pituitary GH via GHS-R1a. trial
- Lineage: Optimized from the Bowers GHRP series (after GHRP-6 / GHRP-1) for higher peak GH and a somewhat cleaner secondary-hormone profile than GHRP-6. trial
- Secondary hormones: Modest transient ACTH/cortisol and prolactin spill at research doses — more than ipamorelin, often framed less harsh than hexarelin/GHRP-6. trial
- Clinical identity: Approved in Japan (PMDA, ~2004) as pralmorelin (GHRP Kaken) for single-dose GH-deficiency provocative testing; not FDA-approved for therapeutic body-comp use in the US. trial
- Evidence honesty: Diagnostic GH tests, short appetite/infusion studies, pediatric episodic-GH work, and comparative endocrine trials exist; no large RCTs for multi-daily gym body-comp protocols. trial
- Not the same as: Not recombinant HGH, not a steroid/SARM, not MK-677 (long oral secretagogue), not “as clean as” ipamorelin on cortisol/prolactin, not a GHRH analog. trial
- Sport status: Explicitly listed under WADA S2 GHRPs (GHRP-2 / pralmorelin) — prohibited at all times for tested athletes. trial
Stacks
- Classic dual pulse: GHRP-2 + CJC-1295 no-DAC / Mod GRF 1-29 — default synergistic GHRH + GHRP stack; often ~100–200 mcg each same syringe. forum
- Sermorelin partner: GHRP-2 + sermorelin as alternate shorter GHRH path in clinic/forum talk. forum
- CJC with DAC + GHRP-2: Still appears for convenience / IGF-1 elevation lore; pulse purists often prefer no-DAC + multi-daily GHRP-2. forum
- Historical GHRP mixes: Older GHRP-2 + GHRP-6 blends; modern logs usually pick one GHRP and one GHRH instead of two GHRPs. forum
- Bulk lifestyle stack: + calorie surplus ± other agents — hunger is often the real intake lever more than peptide “anabolism” alone. forum
- Recovery adjacency: Sometimes next to BPC-157 / TB-500 for soft-tissue goals — confounded, not proven GHRP-2 synergy. forum
- Cleaner swap path: Users chasing less hunger/cortisol/prolactin migrate to ipamorelin + CJC while keeping the same GHRH schedule. forum
- Vs MK-677: Oral continuous secretagogue compared as alternate or (less often) stacked; day-long hunger/water/glucose dominate those debates. forum
- Two-GHRP combinations: Forum discussion commonly favors one GHRP plus one GHRH pathway and calls GHRP-2 plus ipamorelin redundant rather than synergistic. This is community comparison, not an established combination-safety or efficacy finding. forum
Access talk
- 2026 shelves: leftover clinic vials, telehealth “GH peptide” blends that may still say GHRP-2, and RUO lyophilized vials. A Category 3 nomination is not permission to compound. forum
- Not on the July 2026 PCAC seven. trial
- 503A: GHRP-2 sits in Category 3 on FDA’s May 14, 2026 nominated-bulks table — nominated without adequate support, not a bulks-list yes. trial
- 503B Category 2 (injectable and nasal): FDA’s compounding-safety page (still current 2026) flags immunogenicity from aggregation/impurities, an unnatural amino acid that complicates characterization, and reports of serious events in people who received GHRP-2 — increased insulin requirement, infection, pancreatitis, and deaths in critically ill study subjects — causality not established. trial
- Japan diagnostic ≠ gym license: Pralmorelin’s PMDA GH-stimulation-test approval is a single-dose clinical identity, not a multi-daily body-comp path. trial
- WADA S2: Named GHRP (pralmorelin) — prohibited in and out of competition. trial
Labs people mention
- IGF-1 is what people recheck to see if the axis moved. Solo GHRP-2 pulses often nudge morning trough IGF-1 less than DAC-CJC or somatropin IU charts. forum
- Timing of the draw: morning; some skip the night pin. Random GH is too peaky to score. forum
- Glucose / insulin: class GH concern on longer or stacked runs — FDA’s 503B note also mentions increased insulin requirement in the SAE list (causality not established). trialforum
- Prolactin / cortisol: more discussed than on ipamorelin when multi-daily or high mcg; libido/mood posts trigger a PRL check more than a dose increase. forum
- If IGF-1 is flat: empty-stomach timing, missing GHRH partner, or fill/identity — 2026 threads check those before 300 mcg 3×/day. forum
Storage notes
- No mix instructions here: STUDresearch does not list reconstitution, diluent volumes, or syringe unit charts. People reconstitute many different ways and vial labels differ — that content creates more confusion than clarity. forum
- Storage (general talk only): Unopened research products are usually kept cool, dry, and away from light per the seller label. Anything after first use is product-specific — follow the label, not a universal forum SOP. forum
Watch for
- Water retention: Mild edema, ring tightness, face puff, scale jumps from fluid in multi-week logs. forum
- Flush / drowsy / lightheaded: Common minority acute post-injection effects, especially first doses or pre-bed timing. forum
- Injection site: Redness, sting, itch, or small swell — technique, reuse of same site, and product quality are usual suspects. forum
- Glucose / insulin talk: GH-axis stimulation prompts fasting glucose / insulin-sensitivity discussion; some monitor home glucose during aggressive runs. forum
- Carpal-tunnel-like tingling: Hand/finger pins-and-needles framed as GH-related fluid pressure — more discussed on aggressive multi-pulse or stacked GH-axis runs. forum
- Headache / fatigue: Minority reports; stacks, sleep debt, and training confound causality. forum
- Response attenuation fear: Multi-day consecutive use may blunt GH response in older secretagogue data — drives 5-on/2-off or planned off-blocks. forum
- Source / purity risk: Gray-market mislabel, under/over-dose, contamination, and sterile-technique failures are structural. forum
- Malignancy / growth-pathway caution: General GH/IGF-1 pathway caution talk if active cancer history — not a compound-specific risk table. forum
- Not risk-free: Short-study tolerability and diagnostic single-dose use do not prove long-term multi-daily research-chem self-experimentation is safe. forum
- Hunger vs cut: Moderate compared with GHRP-6, still the reason 2026 cut logs swap to ipamorelin. forum
- Water / carpal / glucose: Hand puff, median-nerve tingle, and fasting-glucose talk rise with multi-pulse or GH-axis stacks — community dose-cut signal. forum
- Hunger / overeating: Strongest consistent practical effect (trial food-intake increases and community logs); main cut/recomp downside even though milder than GHRP-6 for many. trial
- Cortisol / ACTH: Transient rises at research IV exposures — Arvat et al. found ACTH/cortisol responses comparable to hCRH at tested doses; usually short-lived (often discussed as returning toward baseline within ~1–2 hours). trial
- Prolactin: Mild-moderate transient bumps (lower than TRH in Arvat comparison); more than ipamorelin in bro ranking tables — libido/mood anecdotes appear at higher multi-daily exposure. trial
- Regulatory: Not FDA-approved for muscle, fat loss, sleep, or anti-aging; Japan diagnostic approval ≠ unsupervised multi-month multi-dose body-comp safety. trial
- WADA: Banned at all times for tested sport (S2 GHRPs). trial
- 503B SAE language is not gym folklore: FDA’s injectable/nasal GHRP-2 note includes infection, pancreatitis, and deaths in critically ill study subjects — causality not established, still the compounding-risk text people quote in 2026. trial
Evidence mix
Mostly community / anecdote tags
Full: every bullet (trial + community). Use Scan for a faster bro-science read.