Growth Hormone Secretagogues (GHS) Explained
Growth Hormone Secretagogues (GHS) are peptides that stimulate the pituitary gland to produce and release natural endogenous Growth Hormone (GH). Unlike synthetic HGH injections, secretagogues maintain the body's natural pulsatile rhythm, reducing the risk of pituitary suppression and insulin resistance.
The two most prominent GHS peptides discussed in longevity and bodybuilding circles are Ipamorelin (a GHRP) and Tesamorelin (a GHRH analog).
Ipamorelin: The Clean Pulse
Ipamorelin is a third-generation Growth Hormone Releasing Peptide (GHRP). It mimics ghrelin to bind to the GHSR (Growth Hormone Secretagogue Receptor). Its primary advantage is its "clean" profile: it stimulates a large GH pulse without elevating cortisol or prolactin—a severe drawback of older GHRPs like GHRP-6 and GHRP-2.
It is excellent for slow, steady body composition changes, sleep optimization, and recovery, making it a favorite for anti-aging protocols.
Tesamorelin: The FDA-Approved Visceral Fat Burner
Tesamorelin is a synthetic analog of Growth Hormone Releasing Hormone (GHRH). It binds to the GHRH receptor. Critically, Tesamorelin holds an FDA approval (originally under the brand name Egrifta) specifically for reducing visceral adipose tissue (VAT) in HIV-associated lipodystrophy.
Clinical studies show Tesamorelin can reduce visceral fat deep in the abdomen by up to 18% over a 26-week period. Because of its targeted fat-mobilization efficacy, it is highly sought after for body recomposition and reducing stubborn belly fat.
Comparing Efficacy and Protocols
When choosing between them, the goal dictates the peptide. For general anti-aging, sleep improvement, and a lower side-effect profile, Ipamorelin (often stacked with CJC-1295) is standard. For aggressive, targeted visceral fat reduction, Tesamorelin is superior but more expensive and frequently causes mild insulin resistance if overused.
Dosing: Tesamorelin is typically dosed at 1mg-2mg daily (usually injected before bed). Ipamorelin is usually dosed at 100-300mcg twice daily. Consult a physician before attempting hormone optimization protocols.