GHRP-2: Tracking a Classic GH Secretagogue

GHRP-2 (Pralmorelin) is one of the original growth hormone releasing peptides — a synthetic ghrelin mimetic that triggers GH release through the GHS receptor. It predates ipamorelin by about a decade and was studied as a diagnostic agent for GH deficiency in Japan. It is not approved by the FDA or EMA for therapeutic use.

What it does

GHRP-2 binds the growth hormone secretagogue receptor (GHS-R, the ghrelin receptor) on the pituitary and triggers a GH pulse. It is more potent on a mg-for-mg basis than ipamorelin but is less selective: it produces small but measurable increases in cortisol and prolactin alongside GH. It also stimulates appetite, though less aggressively than GHRP-6.

When paired with a GHRH analog (CJC-1295 no-DAC, sermorelin, or tesamorelin), the two compounds work synergistically — the GHRH primes the pituitary while the GHRP triggers release.

Typical protocol shape

• Frequency: 1-3 times daily, mirroring natural GH pulse windows
• Dose: 100 mcg per injection is the most commonly reported self-experimenter dose, often paired 1:1 with a GHRH analog
• Timing: pre-bed is standard; post-workout and fasted morning are common additions
• Fasting: at least 60-90 minutes from food in either direction
• Duration: continuous use or cycled blocks are both reported

What to track daily

• Each injection time and dose
• Fasting state at injection
• Acute hunger 15-30 minutes post-injection
• Flush, tingling, lightheadedness
• Time to sleep after evening dose
• Sleep depth
• Mood the next morning (cortisol-related effects show up here)

What to track weekly

• Morning weight and waist
• Recovery quality
• Skin and nail growth (subjective)
• Any acne or oily skin (prolactin/androgen-related shifts)
• Any mood or anxiety changes

Bloodwork worth doing

• Baseline: IGF-1, fasting glucose, HbA1c, fasting cortisol (8am), prolactin, total testosterone (for men), CMP
• Week 6-8: IGF-1, fasting cortisol, prolactin
• Week 12: full repeat

The cortisol and prolactin tracking is what distinguishes a careful GHRP-2 protocol from a careless one. The increases are typically small and clinically irrelevant at standard doses, but they are non-zero and individual response varies.

Realistic expectations

The most reported acute effects are increased hunger and improved sleep onset. IGF-1 changes are modest with pulsatile dosing — typically less than what continuous DAC dosing produces. Body composition changes are slow and easily confounded by the appetite increase. People who track food honestly often find the appetite signal partially offsets the metabolic benefit.

Common mistakes

• Stacking with food (insulin and free fatty acids blunt GH pulses)
• Ignoring cortisol if you already have elevated stress markers
• Using GHRP-2 alone without a GHRH analog (you get a pulse, but a much smaller one)
• Comparing acute "feels" to ipamorelin and concluding more potent equals better

GHRP-2 vs ipamorelin

• GHRP-2: more potent GH pulse per mcg, small cortisol/prolactin bump, modest appetite increase
• Ipamorelin: cleaner selectivity, less appetite effect, slightly weaker pulse

For someone who wants the cleanest possible profile, ipamorelin is the conservative choice. For someone tracking carefully and willing to monitor cortisol, GHRP-2 is reasonable.

A tracking template

Peptid AI works well with a multi-daily injection log, a fasting-state flag per injection, daily sliders for hunger and sleep depth, and a bloodwork module that plots cortisol and prolactin alongside IGF-1 over time. The visual of three biomarkers moving (or not) together is what makes the data useful.

Bottom line

GHRP-2 is an older, more potent, less selective GH secretagogue. It has a place if you respect its non-selectivity and track the relevant biomarkers. If you skip the cortisol and prolactin tests, you're flying blind on the parts of the molecule that matter most for safety.

Peptid AI is an educational and self-tracking tool. Nothing in this post is medical advice. Doses mentioned reflect what is commonly reported in research literature — they are not recommendations. Always consult a qualified physician before starting, changing, or stopping any protocol.