GHRP-2

What it is

GHRP-2 is a six-amino-acid synthetic peptide that mimics ghrelin, the hunger hormone, to tell the pituitary gland to release growth hormone. It is one of the stronger GH-releasing peptides, and it is usually pitched as a more potent but less clean cousin of ipamorelin.

In Japan, pralmorelin (GHRP-2) has been licensed as a diagnostic test to check whether the pituitary can release GH. Outside that use, it is an unlicensed research chemical. It is banned in competitive sport.

History

The growth hormone releasing peptide family was developed in the late 1970s and 1980s by Cyril Bowers and colleagues, starting from enkephalin-like compounds. GHRP-2 followed GHRP-6 as a more potent variant. It was studied through the 1990s and 2000s in GH deficiency diagnostics and in short trials in people with growth problems.

How it works

GHRP-2 binds the ghrelin receptor (GHS-R1a) on the pituitary and hypothalamus, causing a sharp pulse of GH release. It also increases hunger, and unlike more selective options it raises cortisol and prolactin. Your own natural GH pulse is what does the work, so the effect is limited by what your pituitary can release and shuts off with negative feedback.

Dosage

• Commonly reported range is 100 mcg per injection, one to three times a day. Some use 100-300 mcg.
• It is often taken fasted or at least a couple of hours after a meal, because insulin and high blood sugar blunt the GH response.
• Typical courses reported are 8-12 weeks, then a break. These are community numbers rather than trial protocols.

How it is taken

• Subcutaneous injection into belly fat with a 29-31G insulin syringe.
• A common pattern is an injection before bed and one first thing in the morning, with another before training.
• Because it raises hunger, many people prefer to dose away from mealtimes they want to control.

How to reconstitute

• For a 5 mg vial, adding 5 ml of bacteriostatic water gives 1 mg/ml (1,000 mcg/ml). On a 1 ml (100-unit) insulin syringe, 10 units (0.1 ml) is 100 mcg and 20 units is 200 mcg.
• For a 10 mg vial, adding 5 ml gives 2 mg/ml. 5 units (0.05 ml) is 100 mcg and 10 units is 200 mcg.
• Add water slowly down the vial wall, swirl gently, and do not shake.

How it should arrive

A sealed glass vial with an intact cap and a small white lyophilised powder cake.

How it should look once reconstituted

A clear, colourless solution with no cloudiness or particles.

What to expect, and when

• The GH pulse happens within 15-30 minutes of injection.
• Hunger and flushing can be noticed within minutes of a dose.
• Sleep quality, recovery and body composition changes, if any, are reported over weeks to a couple of months.
• Receptors can desensitise with constant use, so effect can fade without breaks.

Side effects

• Increased hunger, though less intense than GHRP-6 for most people.
• Flushing, warmth, tingling or lightheadedness shortly after injection.
• Water retention, puffy hands or swelling.
• Raised cortisol and prolactin: possible tiredness, mood changes, or in men breast tenderness or enlargement (gynecomastia), and in women menstrual disruption.
• Numbness, tingling in hands, joint aches, which are signs of high GH exposure.
• Headache and nausea.

Risks

• Banned by WADA at all times for competitive athletes.
• Raising GH and IGF-1 may raise insulin resistance and blood sugar over time. Long-term effects in healthy people are not known.
• Elevated GH/IGF-1 may promote growth of existing cancers. Anyone with a cancer history should avoid it.
• Cortisol and prolactin elevation make it less clean than ipamorelin.
• No long-term human safety data for recreational or anti-ageing use.
• Quality varies on the grey market.

Potential gains

• Reliable GH pulse in people, which is the best-supported effect.
• Reported improvements in sleep depth, recovery and body composition in community reports; controlled evidence for healthy people is thin.
• Appetite stimulation, which can help in underweight situations but not for people trying to lose weight.

Other useful information

Compared with GHRP-6, GHRP-2 is usually described as stronger for GH with less hunger. Compared with ipamorelin, it is stronger but dirtier (more cortisol and prolactin). It is often paired with a GHRH analogue such as CJC-1295 (no DAC) or sermorelin, because the two together give a bigger GH pulse than either alone. If the main goal is GH, ipamorelin is the more common first choice.