The GH secretagogue category is where strength peptides get most interesting — and most overhyped. These are compounds that nudge your pituitary to release more of its own growth hormone, rather than replacing GH from the outside.
This guide explains what's in the category, how the three main classes differ, the most common stacks, and how to think about secretagogues vs. synthetic HGH if you're comparing options.
The three classes
GH secretagogues fall into three mechanistic families:
| Class | Receptor | Examples | What it does |
|---|---|---|---|
| GHRH analogues | GHRH receptor | Sermorelin, CJC-1295, Tesamorelin | Mimic the natural GHRH signal that triggers GH release |
| Ghrelin mimetics (GHRPs) | GHS-R1a (ghrelin) | Ipamorelin, GHRP-2, GHRP-6, MK-677 | Mimic ghrelin to amplify GH release |
| Combination / bifunctional | Both | CJC-1295 with DAC, certain newer peptides | Activate both pathways for sustained or larger pulses |
The two pathways are synergistic — that's why the classic stack is one of each (Ipamorelin + CJC-1295). Activating both at once produces a larger, cleaner GH pulse than either alone.
The peptide rundown
Sermorelin
The closest commercially-available peptide to natural GHRH — it's the first 29 amino acids of GHRH (1-29). Short half-life (about 10 minutes), so dosed once daily, usually at night. Preserves the body's natural GH pulse pattern. Often considered the gentlest entry point into the category.
| Vial | BAC water | Concentration |
|---|---|---|
| 3 mg | 2 mL | 1.5 mg/mL |
Typical dose: 200–500 mcg before bed. See Sermorelin protocol.
Tesamorelin
A long-acting GHRH analogue. The only GHRH-class peptide FDA-approved (for HIV-associated lipodystrophy — strong visceral fat reduction data). Daily injection. Stronger profile than Sermorelin and a real clinical record behind it.
Ipamorelin
The "cleaner" ghrelin mimetic. Selectively triggers GH release without significantly raising cortisol or prolactin (which is what differentiates it from older GHRPs like GHRP-2 or GHRP-6). Short half-life, dosed 1–3 times daily.
Typical dose: 100–300 mcg per injection.
CJC-1295 (no DAC)
A modified GHRH analogue with a longer half-life than natural GHRH (about 30 minutes vs. 10) but still pulsatile. Almost always paired with Ipamorelin. Dosed at the same cadence as Ipamorelin.
CJC-1295 with DAC
Same backbone as no-DAC, but with a Drug Affinity Complex that extends the half-life to about a week. Produces sustained GH elevation rather than discrete pulses. The trade-off: you lose the pulsatile pattern that mimics natural physiology, and water retention reports are more prominent. Once-weekly dosing.
For the no-DAC vs DAC decision, see CJC-1295 with or without DAC.
MK-677 (Ibutamoren)
The odd one out — not a peptide, but an orally-active small molecule that binds the same ghrelin receptor as Ipamorelin. Once-daily oral dosing (10–25 mg). Major appeal: no injections. Major downsides: pronounced appetite increase, water retention, and some users report deteriorating insulin sensitivity over long runs. See MK-677 vs injectable secretagogues.
The classic stack: Ipamorelin + CJC-1295 (no DAC)
This is the most-reported peptide stack in the strength community. The protocol:
| Compound | Dose | Cadence |
|---|---|---|
| Ipamorelin | 100–300 mcg | 1–3x daily |
| CJC-1295 (no DAC) | 100–300 mcg | 1–3x daily, paired with Ipa |
Most users inject before bed (to align with the body's strongest natural GH pulse) and optionally before training. Some run a third dose post-workout.
Secretagogues vs synthetic HGH
The most common question in this space:
| Property | GH secretagogues | Synthetic HGH (somatropin) |
|---|---|---|
| Source of GH | Your own pituitary | External recombinant protein |
| GH profile | Pulsatile, capped at pituitary capacity | Flat, supraphysiologic |
| Feedback regulation | Intact | Suppressed |
| IGF-1 elevation | Modest | Pronounced |
| Side-effect intensity | Generally milder | More pronounced (water retention, carpal tunnel, insulin resistance) |
| Cost | Lower per dose, daily | High per dose, daily |
| Legal status | Mostly research-chemical / off-label | Schedule III in US (prescription-only, controlled) |
Secretagogues are not a replacement for medically-indicated HGH. They're a different tool — best for people who want a modest GH/IGF-1 nudge without the suppression and side-effect intensity of full HGH replacement.
Side effects across the category
Common to most secretagogues:
- Mild numbness or tingling in hands or feet (especially with DAC formulations)
- Increased appetite (most pronounced with MK-677 and GHRP-6)
- Water retention
- Mild insulin sensitivity changes
- Vivid dreams (often reported as a feature, not a bug)
- Injection-site reactions
Deeper coverage: GH secretagogue side effects.
Who should and shouldn't use GH secretagogues
Most-fitting use cases:
- People in their 30s+ noticing recovery, sleep quality, or body-comp slowdown
- Athletes managing accumulating training damage
- Users who want a modest GH/IGF-1 nudge without the intensity of full HGH
Least appropriate:
- Anyone with active or recent cancer (GH/IGF-1 axis activation is a theoretical concern)
- Diabetics or pre-diabetics (insulin sensitivity can shift)
- People expecting HGH-level results from a secretagogue — the ceiling is much lower