GHRP-2 vs GHRP-6
Two first generation GHRPs from the same lab. Which one releases more growth hormone, and which one makes you eat?
Reviewed by the amino101 editorial team. , first published .
GHRP-2 and GHRP-6 are six amino acid growth hormone releasing peptides from Cyril Bowers' group. GHRP-6 came first, in 1984, and was the probe used to clone the ghrelin receptor a decade later. GHRP-2 followed as a second generation compound with a slightly larger growth hormone pulse. Both act on the same receptor, GHS-R1a, and both raise cortisol and prolactin for an hour or two after every dose, which is the trait that eventually pushed most people to ipamorelin. The practical difference between the two is appetite. GHRP-6 produces an intense wave of hunger within 20 minutes of injection; GHRP-2 produces a moderate one. GHRP-2 is approved in Japan as a single dose diagnostic test for growth hormone deficiency under the name pralmorelin. GHRP-6 has never been approved anywhere. Both are prohibited by WADA, both were placed in FDA Category 2 in 2023, and both were reported as likely to stay restricted after the February 2026 HHS announcement on compounding. This is an educational comparison, not a protocol.
| GHRP-2 | GHRP-6 | |
|---|---|---|
| Typical dosage | 100 to 300 mcg | 100 to 300 mcg |
| Frequency | 1 to 3 times daily | 1 to 3 times daily |
| Route | Subcutaneous, Intranasal | Subcutaneous, Intranasal |
| Half-life | roughly 30 to 60 minutes in plasma | roughly 30 to 60 minutes in plasma (estimated) |
| Cycle | 8 to 12 weeks | 8 to 12 weeks |
| Research level | Well researched | Well researched |
| Human trials | Randomized trials | Randomized trials |
| Status | Approved in Japan as a diagnostic agent for growth hormone deficiency (pralmorelin); not approved anywhere as a treatment. Prohibited by WADA under S2. | Investigational, not approved anywhere. Prohibited by WADA under S2. |
| Effects timeline | hunger and flushing within the hour, deeper sleep 1 to 2 weeks, IGF-1 rise by 4 weeks, body composition 2 to 3 months | hunger within 30 minutes of the first dose, deeper sleep 1 to 2 weeks, IGF-1 rise by 4 weeks, weight gain and recovery 4 to 12 weeks |
Key differences
GHRP-2 vs GHRP-6 dosage
Dosage patterns reported in research and community protocols, by goal. Taken from each compound page. Not a prescription.
| Goal | Dosage | Frequency |
|---|---|---|
| Stacked with a GHRH analog | 100 mcg | once daily before bed, with 100 mcg CJC-1295 no DAC |
| Solo nightly dose | 200 to 300 mcg | once daily before bed |
| Three pulse protocol | 100 mcg | 3 times daily, on waking, after training, before bed |
| Appetite support while bulking | 150 to 200 mcg | twice daily, 30 minutes before main meals |
| Goal | Dosage | Frequency |
|---|---|---|
| Stacked with a GHRH analog | 100 mcg | once daily before bed, with 100 mcg CJC-1295 no DAC |
| Appetite before meals | 100 to 200 mcg | 2 to 3 times daily, 20 to 30 minutes before meals |
| Solo nightly dose | 200 to 300 mcg | once daily before bed |
| Three pulse protocol | 100 mcg | 3 times daily, on waking, after training, before bed |
Convert any of these to syringe units in the dosage calculator.
Side effects compared
- ▲Hunger shortly after a dose
- ▲Flushing, headache or lightheadedness in the first hour
- ▲Water retention and puffy hands at higher doses
- ▲Tingling in the fingers when stacked heavily
- ▲Raised cortisol, which some people feel as restlessness or poorer sleep from daytime doses
- ▲Intense hunger shortly after a dose
- ▲Flushing, headache or lightheadedness in the first hour
- ▲Water retention and puffy hands at higher doses
- ▲Tingling in the fingers when stacked heavily
- ▲Raised cortisol, felt by some as restlessness or poorer sleep from daytime doses
Which should you choose?
GHRP-2 is the fit when you want a larger growth hormone pulse than ipamorelin gives and can accept moderate hunger plus a cortisol and prolactin rise after each dose. It is commonly reported at 100 to 300 mcg, 1 to 3 times daily on an empty stomach, most often as a single bedtime dose. It has the better human record of the two thanks to its Japanese diagnostic approval, though that approval covers one injection in a clinic, not months of daily use.
GHRP-6 is the fit when appetite is the point. Underweight people, hard gainers, and anyone who struggles to eat enough on a gaining phase use it at 100 to 200 mcg, 20 to 30 minutes before meals, so the meal lands as the hunger peaks. For pure growth hormone release it offers nothing GHRP-2 does not, with more hunger. It also works directly against the purpose of any GLP-1 protocol.
Between the two, GHRP-2 is the better growth hormone tool and GHRP-6 is the better appetite tool, and that is really the whole decision. If the goal is the pulse, GHRP-2 gives a little more of it with hunger that most people can manage, especially at bedtime. If the goal is to eat, GHRP-6 does that more reliably than anything else in the secretagogue family, which is why it still turns up in bulking protocols. Neither is the right pick for someone on a fat loss plan, and neither is the right pick for someone who wants to run a secretagogue for months, because the cortisol and prolactin load is shared by both. That is the reason ipamorelin replaced them for most people; see GHRP-6 vs ipamorelin. If you want the biggest pulse available and can live with a short cycle, hexarelin is the other option, covered at hexarelin vs ipamorelin. Whichever GHRP you choose, it is almost always paired with a GHRH analog at 100 mcg each; the protocol is laid out in the GHRP-6 and CJC-1295 stack. None of this is a recommendation; both compounds are unapproved and prohibited in sport.
Stacking: Not stacked with each other, since they share a receptor. Either one is paired with CJC-1295 no DAC at 100 mcg each. Some people alternate: GHRP-6 before meals when hunger is wanted, GHRP-2 at bedtime when it is not.
GHRP-2 is a six amino acid ghrelin receptor agonist that produces a larger growth hormone pulse than ipamorelin but also raises cortisol and prolactin and stimulates appetite. It is licensed in Japan as a diagnostic test for growth hormone deficiency and is used off label in the community as a stronger, less selective alternative to ipamorelin.
GHRP-6 is the original growth hormone releasing peptide, a six amino acid ghrelin receptor agonist that produces a solid growth hormone pulse together with intense hunger and a rise in cortisol and prolactin. People use it when they want appetite as much as growth hormone, usually stacked with a GHRH analog.
GHRP-2 vs GHRP-6: frequently asked
Which is stronger, GHRP-2 or GHRP-6?
GHRP-2 releases somewhat more growth hormone at matched doses, which is why it is called a second generation compound. The difference is modest at 100 mcg, where release is close to saturation for both. Hexarelin outranks both on pulse size, and ipamorelin sits below them with none of the side effects.
Does GHRP-2 make you hungry like GHRP-6?
Less, but yes. A controlled human study found GHRP-2 infusion increased test meal intake by about a third. GHRP-6 produces a sharper, faster hunger that most users describe as the most reliable effect of the peptide. Ipamorelin is nearly neutral. Hunger from either arrives 15 to 40 minutes after a dose and fades within an hour or two.
Do GHRP-2 and GHRP-6 raise cortisol?
Both do. Acute human dosing studies consistently show ACTH, cortisol and prolactin rising alongside growth hormone with either compound, returning to baseline within a couple of hours. Over a long run this can show up as poorer sleep from daytime doses, restlessness, reduced libido or breast tenderness. It is the main reason community cycles for both are kept to 8 to 12 weeks with cortisol and prolactin bloodwork at the end.
Can you take GHRP-2 and GHRP-6 together?
There is no reason to. They act on the same receptor, so a second GHRP adds side effects rather than release. People who want both effects alternate them, GHRP-6 before meals and GHRP-2 before bed, and pair whichever they use with a GHRH analog such as CJC-1295 no DAC, which does add release because it works on a different receptor. See the GHRP-6 and CJC-1295 stack.
Are GHRP-2 and GHRP-6 legal in 2026?
Neither is approved as a treatment anywhere; GHRP-2 is licensed in Japan only as a diagnostic injection. In the US both were placed in FDA Category 2 in 2023, which bars compounding pharmacies from using them. The February 2026 HHS announcement on moving most Category 2 peptides back toward Category 1 reportedly leaves GHRP-2 and GHRP-6 restricted, though nothing has been finalized. Both are prohibited by WADA under S2. They are sold as research chemicals. The broader picture is at the FDA peptide compounding list for 2026.
What GHRP-2 or GHRP-6 dosage is commonly reported?
The same range for both: 100 to 300 mcg per injection, 1 to 3 times daily on an empty stomach, in runs of 8 to 12 weeks. Growth hormone release saturates near 100 mcg, so the upper end mostly buys more hunger, cortisol and prolactin. When stacked with a GHRH analog the common pairing is 100 mcg of each. A 5 mg vial in 2 mL gives 2.5 mg per mL, so 100 mcg is 4 units on an insulin syringe; the calculator handles other vial sizes.
Related reading
Sources
- On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology, 1984
- Growth hormone releasing peptide 2 (GHRP-2), like ghrelin, increases food intake in healthy men. Journal of Clinical Endocrinology and Metabolism, 2005
- Growth hormone releasing peptide 2 (GHRP-2) given nasally or orally stimulates growth hormone release in healthy men. Journal of Clinical Endocrinology and Metabolism, 1992