GHRP-6
Also known as: GHRP-6 Acetate
The hungry one. A ghrelin-mimetic that delivers a real GH pulse but is far better known for the appetite avalanche that arrives twenty minutes after the injection.
Overview
GHRP-6 was one of the first ghrelin receptor agonists synthesised, and its claim to fame is mechanistic clarity: inject it on an empty stomach, set a timer, and within 20 minutes you will be hunting the fridge. The GH pulse is real and comparable to GHRP-2 at equivalent doses, but in practice nobody picks GHRP-6 for the GH — they pick it for the hunger. That makes it the right tool for a narrow set of jobs (hard gainers who can't hit calorie targets, recovery from illness or cachexia, deliberate mass phases) and the wrong tool for everyone else. The hunger does not fully habituate. It will still be there in week 12.[1]
Evidence quality
Small short-term studies from the late 1990s confirmed that GHRP-6 raises GH in healthy adults and stimulates food intake. The appetite finding has been replicated. No large or long-term efficacy or safety trials exist; community use is the bulk of the chronic-dosing track record.
Benefits & timeline
Benefits
- Reliable, time-locked appetite stimulation — useful in cachexia, post-illness recovery, or mass-gain phases
- Solid GH pulse with the secondary recovery and sleep benefits of the secretagogue class
- Cheapest entry point in the GHRP family
- Stacks predictably with a GHRH analogue when the goal is calories plus pulse amplitude
Timeline
Week 1
The hunger arrives like clockwork. Sleep deepens. Some water retention.
Week 2–3
Hunger partially blunts but never disappears. Scale weight starts climbing if calories are available.
Week 4
Recovery between sessions improves. Lean mass and some fat both accumulate, as expected of a bulking signal.
Week 8
GH pulse amplitude tapers; appetite effect persists. The receptor adapts unevenly.
Week 12
Cycle off. Without the peptide, hunger normalises within a few days.
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, pre-meal. Expect significant hunger within 20 minutes of injection — that is the signal you are dosing high enough. Increase to twice daily after 1 week if needed. Maximum 300 mcg three times daily. Cycle off for 4 weeks every 12 weeks. Reduce dose if hunger becomes disruptive.
Injection timing
Pre-meal because the hunger spike helps you eat the calories. Avoid late evening dosing (the hunger can disrupt sleep) unless you are deliberately running a bulking phase.
Side effects & contraindications
- moderateHunger strong enough to derail a fat-loss phase. Plan around it or do not run this peptide.
- mildCortisol and prolactin creep at higher doses, same family pattern as GHRP-2.
- mildWater retention, especially in the first 2 weeks.
- mildMild flushing post-injection.
- moderateNo long-term human safety data. The drug class has been studied acutely; chronic use sits in the grey-market record.
Contraindications
- Active cancer or recent cancer history
- Pregnancy or breastfeeding
- Pre-existing hyperprolactinaemia
- Obesity or binge-eating disorder — the appetite mechanic is incompatible with both
- Type 2 diabetes — GH pulses temporarily worsen insulin resistance
Reconstitution & injection
A 5 mg vial with 2 ml of bacteriostatic water yields 2.5 mg/ml. A 100 mcg dose is 4 units on a U-100 insulin syringe. Subcutaneous, fasted, 20–30 minutes before the meal you want to eat large. Refrigerate after mixing.
Open calculator pre-filledStorage after reconstitution
Refrigerate at 2–8 °C after reconstitution. Do not freeze. Light-protect. 28–30 days of stability at fridge temperature. The molecule is stable; the only thing limiting how long a vial lasts is the dosing schedule, not chemistry.
Cost & sourcing red flags
Typical price range: $20-40 per 5 mg vial from research-grade suppliers. GHRP-6 is one of the cheapest peptides on the market because it has been synthesised since the late 1990s and the raw material is commodity-grade. No FDA-approved version exists.
Red flags
- Vials labelled GHRP-6 priced identically to GHRP-2 from the same supplier. GHRP-6 synthesis is meaningfully cheaper, and reputable vendors price it $5-15 below GHRP-2. Identical pricing is a sign of a generic relabelled bulk powder.
- No batch-specific HPLC chromatogram showing the 872.4 g/mol parent peak. Many low-tier suppliers ship a generic 'GHRP series' COA that covers six peptides at once. Demand a single-product, single-batch document.
- Users who inject and feel zero hunger pang within 30 minutes. GHRP-6 produces the most reliable hunger signal of any secretagogue; a vial that produces nothing is almost certainly underdosed, degraded, or relabelled GHRP-2.
- Vials labelled 5 mg that visibly hold less powder than other 5 mg peptide vials of the same brand. Manufacturers occasionally fill GHRP-6 at 2 mg and label it as 5 mg because the powder is colourless and small fills are visually similar.
- 'GHRP-6 nasal spray' products sold as a needle-free alternative. The peptide has poor intranasal bioavailability and the formulation is essentially placebo. Subcutaneous injection is the only delivery route with published activity data.
- Suppliers who refuse to confirm the synthesis source country. The cheapest GHRP-6 lots come from Chinese contract manufacturers with no GMP certification; reputable US repackers will state this on the COA.
Pricing rots fast and varies by region and supplier. We list no vendors.
Common mistakes
Picking GHRP-6 in a cut.
Better approach: This is the wrong tool. The whole point of GHRP-6 is the hunger; in a deficit, you are paying for a side effect you are trying to avoid. Run Ipamorelin or GHRP-2 instead, and reserve GHRP-6 for mass phases.
Dosing in the evening and being ambushed by hunger at 1 a.m.
Better approach: Dose 20–30 minutes before a planned meal — breakfast, pre-workout, dinner. The hunger window is short and predictable; line it up with food on the table. Late-evening dosing during a fat-loss phase is the most reliable way to break a diet.
Expecting the appetite effect to fade with time.
Better approach: It dulls a little after the first few weeks, but it does not disappear. If after a month the hunger is still derailing the goal, drop the peptide and pick a cleaner GHRP. The appetite is the molecule's defining feature, not a transient side effect.
Running GHRP-6 with no GHRH on board.
Better approach: Same as the rest of the family — the GH amplitude comes from pairing. Sermorelin nightly is the simplest add-on; CJC-1295 stretches the pulse across the day. Solo GHRP-6 gets you the hunger and roughly half the pulse you could otherwise have.
Real-world tips
- Pre-load the meal. If you inject without food in arm's reach, the hunger wins.
- Track scale weight daily during the first 2 weeks — some of it is water and that is normal. The trend after week 3 is what matters.
- Avoid GHRP-6 if you have a complicated relationship with food. The chemical hunger does not respect intent.
- Combine with a GHRH for the pulse, not for the hunger — the appetite effect is unique to the GHRP arm.
- Skip dosing on days when you cannot honour the calories. A missed dose is cheaper than a binge.
What users report
Aggregated from r/Peptides, r/PEDs, MESO-Rx, and ProMuscle threads dating back to 2008. Not clinical data.
Onset: Intense hunger hits within 15-30 minutes of subcutaneous injection and lasts 45-60 minutes; the GH-driven effects on sleep and recovery build over the first 2 weeks of consistent dosing.
Common reports
- Urgent, almost uncomfortable hunger 20-30 minutes post-injection. The standard forum line is 'I had to eat a second dinner', and recomp users specifically time GHRP-6 to force a clean meal rather than fight cravings.
- Mild facial flushing or warm-skin sensation in the first 10 minutes after injection, more common than with GHRP-2 or ipamorelin.
- Deeper sleep with vivid dreams when dosed within 30 minutes of bed.
- Numbness or pins-and-needles in hands during weeks 2-3 from water retention, similar to early-cycle HGH users.
- Loss of hunger response after 6-8 weeks of daily dosing as ghrelin receptors downregulate. Users describe this as 'GHRP-6 stopped doing anything', and most cycle 8 weeks on, 4 weeks off.
- Mild headache or low blood pressure in the first 2-3 days at higher doses (200 mcg+), usually resolved by dropping back to 100 mcg per injection.
Where reports diverge from theory: The peptide is sold for body recomposition, but in practice the strong hunger drive makes it counterproductive for fat-loss phases. Forum consensus has shifted over the last decade: GHRP-6 is now mostly used by people trying to gain weight (cachectic patients, hardgainers, recovery from illness), and bulkers who want a structured eating cue. Anyone running a cut who claims GHRP-6 helps them is almost always actually responding to the GH pulse, and would do better on ipamorelin or GHRP-2 without the appetite side effect.
When something else is the better tool
GHRP-2
Use instead when: You want the GH pulse without the appetite avalanche. GHRP-2 raises hunger noticeably but manageably; GHRP-6 raises it commandingly. For 90% of users, GHRP-2 is the right balance.
Ipamorelin
Use instead when: Long-term, low-side-effect use during a recomp or maintenance phase. Ipamorelin barely touches appetite; GHRP-6 will turn a diet inside out.
Ghrelin / oral ghrelin-mimetics for medical cachexia
Use instead when: If the goal is purely clinical appetite stimulation (cancer cachexia, hospice care), an approved orexigenic agent under supervision is the honest path. GHRP-6 is a research-grade workaround for an indication that has approved alternatives.
Based on 1 peer-reviewed study
- How fast does the hunger hit?
- Around 15–25 minutes after a subcutaneous injection on an empty stomach. It is reliable enough that users set a timer and start cooking when it goes off.
- Will the hunger blunt over time?
- Partially. The first week is the most intense. By week 3 the urgency softens, but the underlying hunger signal stays present for the entire cycle.
- Can I run it for a fat-loss phase if I have great discipline?
- You can, but you are fighting your own pharmacology. Better to choose a peptide whose mechanism aligns with the goal.
- Will I gain fat or muscle?
- Both, in proportion to your training stimulus and protein intake. The peptide does not preferentially route calories to muscle — your training does.
- Is it safe to use with food in my stomach?
- It is safe, but the GH pulse will be blunted by the food-driven insulin/somatostatin response. The appetite spike will still happen, oddly enough.
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