Two different things get called "GH peptides"
Search results and supplier sites often lump "HGH" and "GH peptides" into one category, but they work through different mechanisms and sit at very different regulatory stages. Sorting that out matters more than any comparison of potency.
HGH, the prescription hormone, is somatropin. It is recombinant human growth hormone, an exact copy of the hormone the pituitary makes, produced in bacteria or yeast cells and given by injection. When it enters the blood, it is growth hormone; there is no intermediate step.
GH secretagogues are signals, not hormone. Compounds such as sermorelin, tesamorelin, CJC-1295 and ipamorelin are peptides that bind receptors on the pituitary gland and trigger it to release its own stored growth hormone. MK-677 does something similar through the same ghrelin receptor pathway, though it is a small molecule rather than a peptide, taken as a capsule instead of injected.
How the mechanisms actually differ
Somatropin bypasses the body's own release machinery. Once injected, it circulates as growth hormone and acts on GH receptors throughout the body, including the negative feedback loop that would normally tell the pituitary to slow down. Somatostatin, the hormone that puts the brakes on natural GH release, has no way to stop hormone that is already in the blood.
Secretagogues work upstream of that step. GHRH analogues like sermorelin and tesamorelin bind the GHRH receptor on pituitary cells and prompt a pulse of the pituitary's own GH. Ghrelin-receptor compounds like ipamorelin and MK-677 act on a separate receptor that also triggers GH release, often used to reinforce a GHRH signal. In both cases, somatostatin's brake is still connected: the pituitary's own ceiling still applies, and the release still comes in a pulse rather than a flat level. Whether that makes secretagogues meaningfully safer than direct hormone is a mechanistic argument researchers have made, not something a head-to-head trial has confirmed.
Where each one sits on approval and evidence
| Somatropin (HGH) | Tesamorelin | Other secretagogues (sermorelin, ipamorelin, CJC-1295, MK-677) | |
|---|---|---|---|
| What it is | Growth hormone itself | GHRH analogue | GHRH or ghrelin-receptor signal |
| Route | Injection | Injection | Injection (peptides) or oral (MK-677) |
| Current approval | Approved for defined deficiency and growth conditions | Approved (Egrifta) for one narrow indication | None currently approved |
| Approved indication example | Growth hormone deficiency, Turner syndrome, SGA short stature | Excess abdominal fat in HIV-associated lipodystrophy | Not applicable |
| Trial base | Decades of pharmaceutical development | Phase 3, hundreds of patients | Small studies, weeks to months, mostly in older or specific populations |
Somatropin has the deepest regulatory and clinical record of anything on this comparison, because it has been a marketed hormone replacement for decades, developed for defined deficiency states rather than general use. The Humatrope label, for example, lists approved uses covering paediatric growth failure from inadequate GH secretion, Turner syndrome, idiopathic short stature, SHOX deficiency, short stature in children born small for gestational age, and adult growth hormone deficiency replacement, given by daily subcutaneous injection. Its label reports a subcutaneous half-life of about 3.8 hours.
Tesamorelin is the exception among secretagogues: it went through its own Phase 3 programme and carries a current FDA approval, but only for one specific use, excess abdominal fat in HIV-associated lipodystrophy, not as a general alternative to somatropin. The 2007 pivotal trial randomised 412 adults with HIV to tesamorelin or placebo for 26 weeks and reported a 15.2% fall in visceral fat, with IGF-1 rising 81%.
The rest of the secretagogue group sits further back. Sermorelin's human data comes from small 1990s ageing studies. Ipamorelin and CJC-1295 have thinner human evidence still. MK-677's longest trial, two years in adults aged 60 to 81, raised GH and IGF-1 to young-adult levels and increased fat-free mass, but did not improve strength or function, and a separate hip-fracture trial was stopped early over a heart failure safety signal in a small number of patients.
Side effects follow from the same axis either way
Because both categories ultimately raise growth hormone and IGF-1, they share a family of possible effects: fluid retention, joint and muscle discomfort, and reduced insulin sensitivity or higher glucose. The Humatrope label lists edema, arthralgia, myalgia, carpal tunnel syndrome, hyperglycaemia and impaired glucose tolerance among its adverse reactions. The tesamorelin label lists similar findings plus a specific glucose-intolerance warning. MK-677's two-year trial reported a rise in fasting glucose and a fall in insulin sensitivity. The side effect management guide covers this pattern across the class in more detail, and glucose and IGF-1 are the labs the trial literature points to for monitoring either category; see bloodwork in the Philippines.
The practical distinction
Somatropin is a hormone, approved and prescribed for defined deficiency conditions, with the deepest evidence base of anything discussed here. GH secretagogue peptides are a different category of compound working through the pituitary's own release pathway, and apart from tesamorelin's one narrow approved use, they remain research compounds rather than approved alternatives to hormone replacement. Framing the choice as "HGH vs peptides" as if they were two options for the same approved purpose misrepresents where each one actually stands.
Status in the Philippines
This site has not verified an FDA Philippines registration for any specific somatropin brand or for tesamorelin. Where a somatropin product is prescribed, that belongs with a licensed Philippine physician managing a diagnosed condition. Sermorelin, ipamorelin, CJC-1295 and MK-677 are not approved medicines anywhere at present and circulate in the Philippines only through research-chemical suppliers, outside the pharmacy system.
