Ipamorelin

GHRP-6 is a synthetic six-amino-acid peptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) that tricks the body into releasing its own growth hormone. It was one of the first growth hormone secretagogues ever made, and the hunt to find out why it worked led scientists straight to the discovery of ghrelin. It has no approval as a drug anywhere and is used only as a research compound.

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), specifically a modified GHRH(1-29). The name covers two different products. CJC-1295 with DAC (Drug Affinity Complex) binds blood albumin, which stretches its half-life to roughly 6 to 8 days and raises GH and IGF-I for days from a single injection; this is the version ConjuChem took to Phase II before abandoning it, and the version the human data are about. CJC-1295 without DAC (Modified GRF 1-29, the form this page is named for) lacks the albumin tether and is much shorter acting, though its human half-life has not been formally published. Neither is an approved drug, both are sold only as research chemicals, and GHRH analogs are banned in sport by WADA.

GHRP-2 (generic name pralmorelin) is a synthetic hexapeptide growth hormone secretagogue and a second-generation cousin of GHRP-6. It prompts the pituitary to release growth hormone and is the one peptide in this family with an actual regulatory approval: it is licensed in Japan as a diagnostic agent for growth hormone deficiency. Outside that narrow diagnostic use it has no approval and is sold elsewhere only as a research compound.

MK-677 (ibutamoren) is not actually a peptide, it is a small, orally active non-peptide molecule that mimics ghrelin, your hunger and growth-hormone hormone. Taken as a daily pill, it reliably pushes up growth hormone and IGF-1 levels, which is why it is popular for muscle and recovery. It has been through real human trials but was never approved as a drug, and the trials that mattered most for older adults and Alzheimer's came up short.

Human growth hormone is the real thing rather than a secretagogue: a 191-amino-acid protein identical to what your pituitary makes, produced recombinantly since the 1980s. It is a properly approved medicine for growth hormone deficiency, and it is also the most misused compound in this entire space. Almost everything you read about HGH for anti-aging or physique traces back to a single small 1990 study whose own author later disowned how it was used.

Tesamorelin is a stabilized analog of growth-hormone-releasing hormone (GHRH 1-44) with a chemical modification that protects it from rapid breakdown. It is FDA-approved (brand name Egrifta) to reduce excess visceral abdominal fat in people with HIV-associated lipodystrophy, which makes it one of the few growth-hormone-axis peptides with a real approval behind it. Its evidence base is solid for that specific population and thinner for the general anti-aging and fat-loss uses it gets promoted for online.