GHRP-6 (Growth Hormone Releasing Peptide-6) vs Ipamorelin

Molecular formula

C₄₆H₅₆N₁₂O₆

Molecular weight

873.0 g/mol

Half-life

~2.5 hours

Bioavailability

<1% oral, high subcutaneous

CAS number

87616-84-0

Molecular formula

C₃₈H₄₉N₉O₅

Molecular weight

711.85 g/mol

Half-life

2 hours

Bioavailability

High when injected subcutaneously

CAS number

170851-70-4

Common

• Increased Appetite
• Mild Joint or Muscle Discomfort
• Water Retention or Mild Swelling

Uncommon

• Sleep Disturbances
• Mild Dizziness or Lightheadedness

Serious

• Allergic Reaction

Common

• Mild headache
• Injection site reactions
• Water retention
• Increased appetite

Uncommon

• Tingling in hands or feet
• Joint stiffness

Serious

• Allergic reaction

Evidence level

Limited human trials

FDA status

Research compound

Safety overview

GHRP-6 has a relatively long research history dating back to 1981, with human studies demonstrating its ability to stimulate GH release. The good news is that animal safety studies show excellent tolerability at high doses, and the side effects reported are generally mild and reversible. However, it's not FDA-approved, so use is based on research evidence rather than pharmaceutical oversight. Always purchase from reputable sources and consider medical consultation, especially if you have existing health conditions.

Contraindications

• Known allergy or sensitivity to any component of the peptide
• Active cancer or history of cancer without medical clearance
• Severe cardiovascular disease or uncontrolled hypertension
• Acute critical illness or sepsis

Evidence level

Moderate human trials (Phase 1-2)

FDA status

Research compound

Safety overview

Ipamorelin's main selling point is that it raises growth hormone without raising cortisol or ACTH — two stress hormones that similar peptides do raise. That was shown in pigs, and it held even at doses more than 200 times higher than the amount needed to raise growth hormone [1]. It has not been checked in people. The two published human studies measured ipamorelin and growth hormone only; neither one assayed cortisol, ACTH or prolactin [2][3]. Most of what we know about safety in people comes from a single trial in patients recovering from bowel surgery. 114 people took part: 56 got ipamorelin through an IV for up to seven days, and 58 got a placebo. Most side effects were mild to moderate, and were the kind you would expect after surgery [3]. Serious problems happened at about the same rate in both groups — roughly 1 in 6 either way (17.9% on ipamorelin, 15.5% on placebo). But three things were more common on ipamorelin: low potassium in about 1 in 8 people versus about 1 in 30 on placebo (12.5% vs 3.4%), trouble sleeping in about 1 in 9 versus about 1 in 19 (10.7% vs 5.2%), and high blood sugar at discharge in about 1 in 7 versus about 1 in 12 (14.3% vs 8.6%) [6]. Two people taking ipamorelin died. Both had colon cancer surgery, and in both cases the surgical join in the bowel leaked afterward. Nobody on the placebo died. The FDA says it is unclear whether those deaths had anything to do with ipamorelin — but it pointed to them, along with the potassium and blood sugar differences, when it recommended in October 2024 against letting pharmacies compound ipamorelin [6].

Contraindications

• Active cancer or history of cancer
• Pregnancy or breastfeeding
• Pituitary disorders or tumors
• Known allergy to peptide components
• Children and adolescents (growth plates still open)