Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
GHRP-2
GHRP-2 is a synthetic growth hormone secretagogue that interacts with the ghrelin/growth hormone secretagogue receptor.
Dosing & scaling, explained
The moderated mass amounts below are retained for comparison. Near-duplicates, mix-dependent volumes and device markings are excluded. This is educational source context, not a protocol or recommendation.
Mass amounts available for comparison
- Lower range100 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range500 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
Only mcg or mg amounts are retained. The calculator derives mL, syringe units or pen clicks from the current vial strength, water volume and device.
No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
Verify the exact compound, formulation and amount against the product label or certificate before calculation.
Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for GHRP-2
What published studies and recent community write-ups report about amounts, timing and course length. 7 clinical and 3 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical7 rows | |||||
| Diagnostic GH stimulation test (Japan)77 healthy adults and 58 adults with severe GH deficiency confirmed by insulin tolerance test | 100 mcg | Single injection after an overnight fast | Intravenous | One test with 2 hours of blood samplingNot applicable | European Journal of Endocrinology (PubMed)2007 |
| Peak GH came within 60 minutes in every subject, averaging 85 mcg/L in healthy adults against 1.4 mcg/L in patients, and a cut-off of 15 mcg/L (9 mcg/L with the WHO recombinant standard) matched the 3 mcg/L insulin-test criterion. Responses were slightly lower with age and adiposity, and the test was reproducible on repeat. | |||||
| Graded subcutaneous dosing in GH-deficient children, 8 months6 prepubertal children with GH deficiency and growth failure | 0.3, 1.0 then 3.0 mcg/kg per day; final period 3 mcg/kg GHRP-2 plus 3 mcg/kg GHRH | Once daily, each dose for 2 months | Subcutaneous | 8 months (four 2-month periods)None | Journal of Clinical Endocrinology and Metabolism (PubMed)1998 |
| Overnight GH secretion rose with each dose step and growth velocity was higher on treatment than before or after, but the effect of each injection was brief, GH later in the night was little changed and IGF-I and IGFBP-3 did not rise. No side effects were seen; the authors concluded a longer-acting formulation would be needed for therapy. | |||||
| Oral GHRP-2 for 12 months in GH-deficient children10 prepubertal children with GH deficiency, mean age 10.4 | 900 mcg/kg per dose | Twice daily | Oral | 12 monthsNone | Journal of Pediatric Endocrinology and Metabolism (PubMed)2003 |
| Seven of ten children reported a clear increase in appetite during the first 6 months, but body mass index did not change significantly over the year. The appetite effect was described as transient, and the very high oral dose reflects poor oral bioavailability. | |||||
| Intranasal GHRP-2 in short children, open label15 children with short stature, half of them GH deficient | 5-15 mcg/kg per spray dose (1 mcg/kg intravenous test dose beforehand) | Twice daily for 3 months, then three times daily | Intranasal | 6 months in all children; 18-24 months in sixNone | Journal of Endocrinology (PubMed)1997 |
| Height velocity went from 3.7 to about 6 cm per year and held there to 2 years, while IGF-I, IGFBP-3 and the acute GH response to GHRP-2 did not change. The study had no control group, and the later placebo-controlled trial below did not confirm a growth effect. | |||||
| Placebo-controlled intranasal spray trial, 48 weeks (negative)126 prepubertal children with GH deficiency who responded to a test spray | 50 or 100 mcg (under 20 kg) and 100 or 200 mcg (20 kg or more) per dose | Twice daily, morning and evening | Intranasal spray | 48 weeks, double-blindNone | Clinical Pediatric Endocrinology (J-STAGE)2014 |
| Height SD score changed by 0.07, 0.03 and 0.02 in the placebo, low-dose and high-dose groups, with no difference between them and no change in IGF-I. The authors concluded that the brief GH rise after each spray was too small to produce a biological effect. | |||||
| 30-day continuous subcutaneous infusion in older adults5 men and 5 women with age-related low GH secretion and low IGF-1 | 1 mcg/kg per hour (acute bolus comparisons at 0.1, 1 and 10 mcg/kg) | Continuous | Subcutaneous infusion | 30 daysNot described | Endocrine (PubMed)2001 |
| Pulsatile GH secretion and serum IGF-1 rose within 24 hours of starting the infusion and stayed elevated for the full 30 days, and an acute 10 mcg/kg subcutaneous dose gave about twice the GH response of 1 mcg/kg. With ten participants and no placebo arm, it is a physiology study rather than an efficacy trial. | |||||
| Appetite study in lean men7 lean healthy men | 1 mcg/kg per hour | Single 270-minute infusion, crossover with saline | Subcutaneous infusion | One session per conditionNot applicable | Journal of Clinical Endocrinology and Metabolism (PubMed)2005 |
| Every participant ate more at a buffet meal during GHRP-2 than saline, 36% more on average, with no shift in macronutrient choice, while GH exposure rose more than tenfold. The result established GHRP-2 as a ghrelin mimic for appetite in humans, which is also the basis of the hunger reported in community use. | |||||
| Community-reported3 rows | |||||
| Wiki protocol table (research and diagnostic) | 100-300 mcg per injection (100 mcg intravenous for the diagnostic test) | 2-3 times daily on an empty stomach, 30 minutes clear of food | Subcutaneous | 8-12 weeks5 days on, 2 days off suggested because of tachyphylaxis within 1-4 weeks of daily use | Community resource2026 |
| Updated January 2026, this wiki reports peak GH 30-60 minutes after a subcutaneous dose with a return to baseline within 3-4 hours, which is why protocols stack two or three injections a day with a pre-sleep dose as the most common single dose. It suggests morning cortisol and prolactin checks and states there is no approved therapeutic dose. | |||||
| Community chart with weekday cycling | 100-300 mcg (5, 10 or 15 units at 2 mg/mL from a 10 mg vial in 5 mL) | 2-3 times daily, at least 3 hours apart, 30-60 minutes before meals | Subcutaneous, abdomen or thigh | 8 weeks on5 days on and 2 days off each week; 8 weeks off between cycles | Community resource2026 |
| This 2026 chart puts the most common community dose at 100-200 mcg, which it equates to the 1-2 mcg/kg clinical range, and attributes the weekend break to attenuation seen with consecutive daily dosing in a five-day study. It quotes a 15-30 minute half-life and describes the 8-on, 8-off pattern as a cost and normalization convention. | |||||
| Tiered dose and cycle table | 100 mcg (beginner), 200 mcg (intermediate, most common), 300 mcg (advanced) | 2 times daily fasted (beginner) to 3 times daily (advanced) | Subcutaneous | 8-12 weeks standard; 12-16 weeks extended4-6 weeks off (standard) or 6-8 weeks off (extended); optional 5 on/2 off | Community resource2026 |
| Reviewed February 2026, this guide describes a saturating dose-response in which going above 200-300 mcg adds cortisol, prolactin and appetite effects without proportionally more GH, and recommends IGF-1 and prolactin checks above 200 mcg. It rates its own evidence as moderate because the human data are diagnostic and short-term pharmacology rather than treatment trials. | |||||
How a course is commonly described
- Weeks 1-2Community-reported
Community guides start at 100 mcg subcutaneously twice a day on an empty stomach, usually fasted in the morning and before bed, to gauge hunger, flushing and any cortisol or prolactin symptoms before moving up.
- Weeks 3-8Community-reported
The usual working dose is 200 mcg two or three times a day at least 3 hours apart, often only on weekdays. Guides describe this as the window in which sleep and recovery changes are reported, with no trial measuring any of it.
- Weeks 9-16Community-reported
Extended cycles run to 12-16 weeks at up to 300 mcg three times a day, with IGF-1 and fasting glucose checks suggested. Wiki sources warn that GH response attenuates within 1-4 weeks of uninterrupted daily dosing, which is their argument for intermittent schedules.
- BreakCommunity-reported
Off periods of 4-8 weeks follow an 8-16 week cycle, with some charts matching the break to the cycle length (8 on, 8 off). Sources give receptor recovery, cost and normalization of IGF-1 and cortisol as the reasons; none cites a study of the break itself.
- Clinical comparisonClinical
The longest adult exposure in the literature is a 30-day continuous infusion at 1 mcg/kg per hour in ten older adults, which kept GH pulsatility and IGF-1 elevated throughout. In children, 8 months of daily injections raised growth velocity without raising IGF-I, and 48 weeks of twice-daily sprays did nothing for growth.
- GHRP-2 is approved only as a 100 mcg intravenous diagnostic test in Japan. No treatment trial has used the 100-300 mcg subcutaneous schedule, and the only placebo-controlled treatment trial (intranasal, 48 weeks, 126 children) was negative for growth.
- Each injection produces a short GH pulse that returns to baseline within hours; the pediatric studies found no rise in IGF-I from once-daily injections, which is why community protocols use two or three doses a day. Appetite stimulation is a documented effect in humans, not just a community observation.
- Cycling and weekend breaks are community conventions built on reports of attenuated response with daily dosing; no study has tested a cycle length or off period. The rows above describe what sources report, not recommendations.
Sources for this section (10)
- A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency
- Effects of eight months treatment with graded doses of a growth hormone (GH)-releasing peptide in GH-deficient children
- Changes in appetite and body weight in response to long-term oral administration of the ghrelin agonist GHRP-2 in growth hormone deficient children
- Treatment effects of intranasal growth hormone releasing peptide-2 in children with short stature
- Increased Secretion of Endogenous GH after Treatment with an Intranasal GH-releasing Peptide-2 Spray Does Not Promote Growth in Short Children with GH Deficiency
- Growth hormone/insulin-like growth factor-1 response to acute and chronic growth hormone-releasing peptide-2, growth hormone-releasing hormone 1-44NH2 and in combination in older men and women with decreased growth hormone secretion
- Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men
Plus 3 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
GHRP-2 (pralmorelin, KP-102) is a synthetic six-amino-acid growth hormone secretagogue from Cyril Bowers' GHRP series that acts on the ghrelin receptor rather than the GHRH receptor, producing a short, sharp GH pulse and, like ghrelin, stimulating appetite. Its one approved use is diagnostic: a 100 mcg intravenous dose sold in Japan as GHRP Kaken 100 to test for adult GH deficiency, validated against the insulin tolerance test in 2007. Between 1995 and 2014 it was also studied as a treatment for GH-deficient children by subcutaneous, intranasal and oral routes, and a 126-child, 48-week placebo-controlled intranasal trial found no effect on growth. It has no approved therapeutic indication anywhere, and the 100-300 mcg subcutaneous schedules in circulation come from community and practitioner practice rather than from treatment trials.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
What is GHRP-2?
Synthetic secretagogue and discovery background
- 2
Research Highlights
Preclinical findings across multiple systems
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
What is GHRP-2?
Synthetic secretagogue and discovery background
- Not graded
Research Highlights
Preclinical findings across multiple systems
Amounts recorded for GHRP-2
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
- 1Dose · lower endpointSign in for schedule, duration and source context.100 mcg
- 2Dose · upper endpointSign in for schedule, duration and source context.500 mcg
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Sequence
D-Ala-D-(2-naphthyl)Ala-Ala-Trp-D-Phe-Lys-NH2
Also listed as
Pralmorelin [INN], GHRP-2, KP-102, GPA-748, GHRP Kaken 100 (Japanese diagnostic product), D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2, UNII E6S6E1F19M, CHEMBL106593
InChIKey
HRNLPPBUBKMZMT-RDRUQFPZSA-N
IUPAC name
(2S)-6-amino-2-[[(2R)-2-[[(2S)-2-[[(2S)-2-[[(2R)-2-[[(2R)-2-aminopropanoyl]amino]-3-naphthalen-2-ylpropanoyl]amino]propanoyl]amino]-3-(1H-indol-3-yl)propanoyl]amino]-3-phenylpropanoyl]amino]hexanamide
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.