HGH Fragment 176-191 dosage and evidence

What is HGH Fragment 176-191?

How does HGH Fragment 176-191 work?

It copies the fat burning action of growth hormone's tail end on fat cells, without growth hormone's growth effects or blood sugar effects.

What have studies in people found about HGH Fragment 176-191?

No study of this fragment in people has ever been published under this name. The human record people quote belongs to AOD-9604. That is the same piece of growth hormone with one extra building block added at the front. Its record is a 24-week weight-loss study in 502 people that did not beat a dummy pill.

• Through the near-identical AOD-9604: the 24-week weight-loss study signed up 534 people and put 502 into groups. It did not beat the dummy on weight loss, the goal it was built to test. The company ended the obesity project in 2007.
• Through AOD-9604: across six studies against a dummy, where nobody knew who got what, it did not change IGF-1 in the blood and did not harm blood sugar control on a sugar test. Nobody dropped out or had a serious side effect linked to it.
• No studies in people of HGH Fragment 176-191 itself. PubMed's 23 records for AOD9604 include one paper in people, the safety summary of six AOD9604 studies. No paper gives the plain fragment to a person.
• No registered trials. ClinicalTrials.gov lists no study of this fragment, AOD-9604 or AOD9604.
• FDA's safety page on compounding substances, updated 22 April 2026, lists AOD-9604. FDA says it does not have enough information to know whether it would harm people. It also says it has found serious side effects that may be linked to it, though it is not clear the drug caused them.
• The animal result it is actually sold on: in fat rats, AOD9401, the 177-191 fat-burning piece of growth hormone, was given by mouth at 500 mcg/kg a day for 19 days. It cut weight gain by more than half. The treated rats gained 15.8 grams against 35.6 grams in untreated rats, with no harm to how well insulin worked. Rats, by mouth, for 19 days.

What this does not tell you: There is no study of how the plain fragment behaves in people, no work to find a dose, no measure of fat or any other result, and no test of the shot under the skin it is sold for. Using the AOD-9604 record for it means assuming the two act the same in a person, which nobody has tested. The rat results came from 19 days of dosing by mouth. They say nothing about what a shot does in a human.

What do people who took HGH Fragment 176-191 report?

This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.

• The most consistent thing in these threads is disappointment. Long-standing posters describe it as having failed to deliver what was expected of it, including one account of four months of use with nothing observed, and it is repeatedly described as an idea that did not turn into results.
• Doses described cluster around 500 mcg a day, either as a single fasted dose or split, with others describing 250 to 350 mcg three times a day spaced several hours apart.
• Fasting is treated as a condition of use rather than an option, and the demand to stay fasted for much of the day is itself given as a reason people stopped.
• The recurring comparison is unfavourable. People say growth hormone itself, and the GHRP family, gave them more fat loss and more besides, while this asks for more compliance and returns less.
• Where fat loss is reported it is described alongside a deliberate diet and training programme, and experienced posters state plainly that nothing happens from the compound alone.
• Side effect discussion is sparse, with blood pressure raised as a question rather than an observation. The dominant negative here is absence of effect rather than harm.

Sources: EliteFitness peptide threads and an ExcelMale thread on the fragment, found by site-restricted search and read directly, September 2026. Nothing above is attributed to any specific post and no post is reproduced.

The state of the research

The evidence, in charts

The studies we cite

• Review of studies2026
  The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration

  The fragment sold under this name is the same molecule as AOD-9604, and that molecule failed its weight loss trial. This review spells out the chemistry. AOD9604 is the 177 to 191 piece of growth hormone with one extra amino acid on the front, which is why it also gets written 176-191. It records the 24 week study of 534 people, 502 of them sorted into groups, which missed the weight loss it was built to show.

  Describes AOD9604 as hGH(177-191) with an additional N-terminal tyrosine, hence sometimes labelled hGH 176-191 or GH fragment, and records the 24-week obesity study of 534 subjects with 502 randomized that missed its primary weight-loss endpoint.

  PMID 42395176 Frontiers in Endocrinology
• Review of studies2026
  Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks

  This is a regulator's notice about manufacturing risk, not a study. FDA lists AOD-9604 for the risk that an injected peptide sets off the immune system, and for the difficulty of showing what is actually in the vial. It states it does not have enough information to know whether the drug would harm a person. Nothing on the page says whether it works.

  AOD-9604 is listed for immunogenicity risk by certain routes and for peptide-related impurity and characterization complexities, with FDA stating it lacks sufficient information to know whether the drug would cause harm when administered to humans. Updated 22 April 2026.

  Source U.S. Food and Drug Administration
• Animal study2000
  Molecular and cellular actions of a structural domain of human growth hormone (AOD9401) on lipid metabolism in Zucker fatty rats

  In obese rats, the tail end of growth hormone copied growth hormone's fat burning in fat tissue and slowed weight gain, without blood sugar problems.

  The C-terminal 177-191 domain of hGH mimicked GH's lipolytic actions on adipose tissue and reduced weight gain in obese rats without insulin resistance.

  PMID 11116208 Journal of Molecular Endocrinology
• Animal study2000
  Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism

  In obese mice, 30 days of the growth hormone fragment by mouth slowed weight gain without changing how much they ate. In a dish, it also sped up fat breakdown in fat tissue taken from obese rodents and from people.

  30 days of oral hGH fragment (AOD-9401) lowered weight gain in ob/ob mice without changing food intake and increased lipolysis in obese rodent and human adipose tissue ex vivo.

  PMID 10950816 American Journal of Physiology: Endocrinology and Metabolism
• Animal study2001
  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

  In obese mice, the stabilized version AOD9604 cut body weight and fat. The closest human data come from the AOD9604 studies, not from this fragment.

  The stabilized fragment analogue AOD9604 reduced body weight and fat in obese mice; the closest human data come from the AOD9604 programme, not the native fragment.

  PMID 11713213 Endocrinology
• Animal study2000
  Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone

  In rats, fed by mouth, over 19 days. That is where the fat-loss story for this fragment comes from. Fat rats given the peptide daily gained less than half the weight the untreated rats gained, and their response to insulin was not harmed. They swallowed it. People buy it as a shot. Nothing here was measured in a human, and nobody has checked whether a shot in a person does anything like this.

  Oral AOD9604 at 500 mcg/kg for 19 days in obese Zucker rats reduced body-weight gain by over 50%, 15.8 plus or minus 0.6 g against 35.6 plus or minus 0.8 g in controls, with no adverse effect on insulin sensitivity by euglycemic clamp.

  PMID 11146367 Hormone Research