What Is GHRP-6? Dosage, Half-Life & How to Track It
Also known as: Growth Hormone-Releasing Peptide-6 · SK&F 110679 · GHRP-6 acetate
GHRP-6 is a synthetic six-amino-acid peptide, one of the original ghrelin-mimetic GH secretagogues, best known for a strong appetite-stimulating effect alongside its GH pulse. Typical protocols run 100–300 mcg per injection, often one to three times daily on an empty stomach; its half-life is roughly 2–2.5 hours. Often paired with a GHRH analog. Educational information only.
What GHRP-6 is and how it works
GHRP-6 is a synthetic hexapeptide — one of the first ghrelin-mimetic growth-hormone secretagogues developed, originally studied under the code SK&F 110679. Like Ipamorelin and GHRP-2, it activates the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus to trigger a GH pulse.
What sets GHRP-6 apart is how strongly it also acts on ghrelin’s other job: hunger signaling. Where Ipamorelin mostly avoids this and GHRP-2 does it mildly, GHRP-6 reliably produces a noticeable — sometimes intense — appetite spike within 15–30 minutes of an injection. Some people specifically choose it for that reason during a bulk; others find it works directly against a cut.
As with the rest of the GHRP family, it triggers GH release through the pituitary’s own machinery rather than replacing GH directly, so the size of the pulse still depends on the body’s feedback loop — which is why it is often paired with a GHRH analog for a bigger combined effect.
Typical dosing & reconstitution
GHRP-6 is reconstituted from lyophilized powder with bacteriostatic water. A common protocol is 100–300 mcg per injection, one to three times daily, spaced at least a few hours apart and taken on an empty stomach — a recent meal blunts the GH response.
Reconstitution sets your concentration, and concentration sets your syringe units:
| Vial | BAC water | Concentration | 1 unit (U-100) ≈ |
|---|---|---|---|
| 2 mg | 3 mL | 0.67 mg/mL | 6.7 mcg |
| 5 mg | 3 mL | 1.67 mg/mL | 16.7 mcg |
| 10 mg | 3 mL | 3.33 mg/mL | 33.3 mcg |
At 1.67 mg/mL, a 200 mcg dose is 12 units. Running three injections a day makes the reconstitution math matter three times as often — the calculator locks in the units once so you are not redoing arithmetic at every dose.
Half-life & what it means for frequency
GHRP-6 clears from the blood in roughly 2–2.5 hours, short enough that multiple daily doses produce multiple distinct GH pulses rather than one sustained elevation. That is the reason protocols often call for two or three injections a day rather than a single bedtime dose.
Because each dose also brings its hunger effect, the practical schedule usually gets built around meals as much as GH timing — dosing on an empty stomach 20–30 minutes before eating is a common pattern, which doubles as an appetite cue.
What to track & common side effects
GHRP-6’s signature side effect is the strong hunger spike, which is either the point or the problem depending on the goal. Beyond that, expect the same general GHRP profile: injection-site irritation, mild water retention, and — more than Ipamorelin, comparable to GHRP-2 — some transient cortisol and prolactin elevation.
With multiple daily doses, the thing that is easiest to lose track of is simply how many shots you actually took today and whether you ate around each one as intended. Logging each injection with its time, plus sleep and body-composition trends, keeps the protocol honest.
How to track GHRP-6 in Stackeddd
Log each GHRP-6 shot — with multiple doses a day, "did I already pin this afternoon?" is the real failure mode. Track hunger and eating alongside it so the appetite effect works for your goal instead of against it. Get the reconstitution locked in once so every dose across the day is accurate.
Model it yourself · free, no account
Reconstitution Calculator
Model it yourself: enter your vial size and BAC water and the Peptides tab returns concentration and exact insulin-syringe units for any dose — the same math built into the Stackeddd app.
Related compounds
Related reading: What peptides can you mix in the same syringe? · Peptide reconstitution math: how much BAC water to add
Frequently asked questions
What is GHRP-6 used for?
GHRP-6 is a growth-hormone secretagogue studied for GH/IGF-1 support, recovery, and — because of its strong ghrelin-receptor activity — appetite stimulation. It was one of the earliest peptides in this class and is not FDA-approved for human use.
What is the half-life of GHRP-6?
Roughly 2 to 2.5 hours, which is why protocols often call for two or three doses a day rather than one.
Does GHRP-6 make you hungry?
Yes, noticeably — this is its defining characteristic among the GHRPs. Hunger typically hits within 15–30 minutes of a dose. It is stronger than GHRP-2’s appetite effect and far stronger than Ipamorelin’s, which is why compound choice within this family often comes down to whether that side effect helps or hurts your goal.
What is the difference between GHRP-6 and Ipamorelin?
Both trigger GH release through the same ghrelin receptor, but Ipamorelin is far more selective — it largely spares appetite, cortisol, and prolactin, while GHRP-6 reliably raises all three alongside the GH pulse. Ipamorelin is the more common default; GHRP-6 is chosen specifically when the appetite effect is wanted.
This is educational information, not medical advice. Doses and protocols above reflect published references and community practice — protocol decisions belong with your prescribing physician. Generic names used throughout. How this reference is built & how the AI is tested →
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