What it is
HGH Fragment 176-191 is the lipolytic C-terminal region of human growth hormone (HGH), where lipolytic means involved in breaking down fat. AOD-9604 is a stabilized derivative of it. The fragment is studied for fat metabolism without the full growth hormone effects.
In the PeptidesAI encyclopedia it is categorized under weight loss and growth hormone.
How it's thought to work
HGH Fragment 176-191 isolates the fat-reducing region of HGH, stimulating lipolysis and inhibiting lipogenesis (fat formation) while avoiding the IGF-1 and blood-sugar effects of full growth hormone. AOD-9604 is a tyrosine-stabilized version of this fragment.
What the research says
Preclinical work supports lipolytic activity of the 176-191 region. Human data is limited, and the fragment is not FDA-approved.
In obese mice, a lipolytic fragment of human growth hormone synthesized from its C-terminus (AOD9604) reduced body weight and body fat and increased lipolytic sensitivity after chronic treatment.
In a separate study, a small synthetic peptide sequence of human growth hormone increased lipolytic activity and decreased lipogenic activity in adipose tissue isolated from obese rodents and from humans, and reduced weight gain in obese mice.
Reported side effects
Reported side effects include injection site irritation, mild flushing and occasional headache. Human data on the fragment is limited.
Reconstitution
HGH Fragment 176-191 is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 5 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 5 mg vial is 5,000 mcg. Reconstituted with 2 mL of BAC water, that works out to 5,000 mcg ÷ 2 mL = 2,500 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 2,500 × 0.01 = 25 mcg. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
HGH Fragment 176-191 is not FDA-approved and is listed as prohibited by the World Anti-Doping Agency (WADA). AOD-9604 is the more stable derivative of this fragment.
Sources
- The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Heffernan M et al. Endocrinology, 2001. Preclinical
- Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism. Heffernan MA et al. American Journal of Physiology - Endocrinology and Metabolism, 2000. Preclinical
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is HGH Fragment 176-191?
The lipolytic C-terminal region of human growth hormone, studied for fat metabolism without full growth hormone effects.
How is HGH Fragment 176-191 thought to work?
It is described as stimulating lipolysis and inhibiting lipogenesis while avoiding the IGF-1 and blood-sugar effects of full growth hormone.
What does the research on HGH Fragment 176-191 say?
Preclinical work, including obese-mouse studies of related growth hormone peptides, supports lipolytic activity; human data is limited.
What are the reported side effects of HGH Fragment 176-191?
Injection site irritation, mild flushing and occasional headache are listed; human data is limited.
How much is one unit from a 5 mg HGH Fragment 176-191 vial?
With 2 mL of BAC water, a 5 mg vial is 2,500 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 25 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for HGH Fragment 176-191 — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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