🔑 Key Takeaways
- GHRP-6 = Growth Hormone Releasing Peptide-6 — stimulates GH release via the ghrelin receptor, causes strong appetite increase
- Gonadorelin = synthetic GnRH — stimulates LH/FSH production, used on TRT to maintain testicular function and fertility
- These are completely different peptides with different purposes — often searched together because both are available as research peptides
- GHRP-6 is available from multiple US vendors; Ascension carries the FIT Stack (CJC-1295 + Ipamorelin) as a cleaner alternative
- Gonadorelin is available from Core Peptides, Biotech Peptides, and other US sources
- Both require reconstitution with BAC water before use
GHRP-6 and gonadorelin often appear in the same searches, but they do completely different things. GHRP-6 is a growth hormone releasing peptide — it stimulates GH pulses and is known for causing a strong appetite spike. Gonadorelin is synthetic GnRH — it's used primarily by men on TRT to keep their natural testosterone production and fertility intact. This guide covers both: what they are, where to buy them, how to use them, and what to expect.
GHRP-6 — What It Is and What It Does
Full name: Growth Hormone Releasing Peptide-6. It's a hexapeptide — six amino acids — that binds to the ghrelin receptor (GHS-R1a) in the pituitary gland, triggering a pulse of growth hormone. Unlike GHRH analogs like CJC-1295, GHRP-6 acts through an entirely different receptor pathway. That's exactly why stacking them works so well — they hit the same downstream outcome (GH release) from different angles, producing a synergistic effect greater than either alone.
The effects you'll notice: GH pulse effects (improved recovery, fat metabolism support, muscle growth over time), significantly improved sleep quality, and — the most talked-about effect — a strong, acute appetite spike. People call it the "hunger peptide" for a reason. Within 30–60 minutes of a GHRP-6 injection, you'll typically feel noticeably hungry. For someone bulking, this is a feature. For someone cutting, it requires planning around.
Half-life is very short — roughly 15–20 minutes. That means multiple daily dosing is required if you want sustained GH elevation throughout the day. One injection doesn't cut it.
| GHRP-6 | Ipamorelin | |
|---|---|---|
| GH release potency | Strong | Moderate |
| Appetite stimulation | Very strong (a feature for bulking) | Minimal |
| Cortisol increase | Moderate | Minimal |
| Prolactin increase | Moderate | Minimal |
| Dosing frequency | 2–3x daily | 1–2x daily |
| Best for | Bulking, aggressive GH pulse | Leaning out, cleaner GH support |
GHRP-6 Dosage
Standard dose is 100–300mcg per injection, taken 2–3 times daily. The sweet spot for most people is 100–200mcg — there's some evidence that going above 300mcg doesn't produce meaningfully more GH and just amplifies side effects (mainly hunger and temporary cortisol/prolactin elevation).
Timing matters a lot: Take GHRP-6 on an empty stomach. Food — particularly carbohydrates and fats — significantly blunts the GH response. Inject 30–60 minutes before eating. Common windows: first thing in the morning, before a workout, and before bed.
Cycle length: 8–12 weeks, then 4 weeks off. Receptor desensitization is a real issue with GHRP-6 — continuous use without breaks reduces effectiveness. Taking time off lets GHS-R1a receptor expression recover.
Where to Buy GHRP-6
Core Peptides is one of the most consistently recommended US-based sources — HPLC tested, domestic shipping, clean track record. Several other established US vendors carry 5mg vials in the $30–60 range.
Ascension Peptides doesn't stock standalone GHRP-6, but for most goals, the FIT Stack (CJC-1295 + Ipamorelin) is a cleaner alternative. Ipamorelin works through the same ghrelin receptor as GHRP-6 but with minimal appetite stimulation, no cortisol spike, and lower prolactin impact. For people who don't specifically want the appetite effect, ipamorelin paired with CJC-1295 is a more practical daily protocol.
What to look for in any GHRP-6 vendor: HPLC COA from a third-party lab, ≥98% purity, US-based operation, clear contact information.
Gonadorelin — What It Is and What It Does
Gonadorelin is the synthetic form of gonadotropin-releasing hormone (GnRH) — the signal the hypothalamus sends to the pituitary to trigger luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. It's a 10-amino-acid peptide, and it's structurally identical to endogenous GnRH.
The primary application is TRT support. When men inject exogenous testosterone, the body interprets elevated testosterone levels as a signal to stop producing its own — which means the hypothalamus stops sending GnRH, the pituitary stops making LH, and the testes stop producing testosterone and sperm. The testes literally shrink over time from disuse. Gonadorelin breaks that feedback loop at the pituitary level, keeping LH and FSH production active and maintaining testicular function.
Half-life is extremely short — roughly 2–4 minutes in circulation. This sounds impractical, but the pituitary still responds to the brief stimulation. Dosing 2–3 times per week subcutaneously is the standard protocol for TRT support.
Gonadorelin also has applications in fertility protocols, puberty induction in certain clinical contexts, and occasionally in women's health for ovulation induction. But for most people searching this topic, the TRT angle is what matters.
| Gonadorelin | HCG | |
|---|---|---|
| Mechanism | Stimulates pituitary → LH/FSH | Directly mimics LH |
| Natural LH stimulation | Yes — pituitary still active | No — bypasses pituitary |
| Effect on testicular function | Maintains LH pathway | Maintains via LH mimic |
| Fertility preservation | Yes | Yes |
| Availability | Research peptide (no Rx) | Prescription required (brand) |
| Dosing frequency | 2–3x/week or daily | 2–3x/week |
Gonadorelin Dosage
Standard TRT maintenance protocol: 100–200mcg, 2–3 times per week, subcutaneous injection. Some protocols prefer daily low-dose (50–100mcg/day) to provide more consistent pituitary stimulation rather than larger, less frequent pulses.
Because gonadorelin's half-life is so short, timing within the day matters less than consistency. The pituitary responds to the stimulation pulse regardless of time of day.
Unlike GHRP-6, gonadorelin isn't typically cycled off. It's used continuously alongside TRT as a maintenance protocol, not a temporary stack. Stopping it while remaining on TRT brings you back to the same suppression problem.
Where to Buy Gonadorelin
Core Peptides carries a 10mg gonadorelin vial that's consistently well-reviewed — US-made, HPLC tested. Biotech Peptides is another reliable source with third-party testing. Typical price range is $50–100 for a 10mg vial.
The same vendor criteria applies: third-party HPLC COA, ≥98% purity, US-based. Gonadorelin is a relatively stable peptide when stored correctly (refrigerated, away from light), so quality is less about storage concerns and more about whether the original synthesis was accurate.
Can You Stack GHRP-6 and Gonadorelin Together?
Yes — and there's no interaction to worry about because they operate on completely separate systems.
- GHRP-6: pituitary → GH release via ghrelin receptor
- Gonadorelin: pituitary → LH/FSH → testosterone production via GnRH receptor
Different receptors, different downstream effects, no cross-reactivity. Men on TRT who also want GH support stack these routinely — gonadorelin to preserve testicular function while on testosterone, GHRP-6 (or a GH peptide stack) for the GH benefits. They just happen to both be pituitary-acting peptides; they're not competing for anything.
💡 Practical Stack for Men on TRT
Gonadorelin 100–200mcg 2–3x per week (maintain testicular function and fertility) + FIT Stack or GHRP-6 1–2x daily (GH support, recovery, sleep). Both require BAC water reconstitution. Keep separate vials clearly labeled.
Frequently Asked Questions
The information in this article is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional before starting any new supplement or compound. Results vary by individual.