HGH Fragment 176-191 vs NA-931
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Frag 176-191, HGH Frag
HGH Fragment 176-191 is exactly what it sounds like: a short tail-end piece of the human growth hormone molecule, amino acids 176 through 191. The idea was to keep the fat-burning part of growth hormone while ditching the parts that raise blood sugar and IGF-1. The optimized drug version, AOD-9604, actually went through real human trials for obesity, and the blunt result is that it was very safe but did not produce meaningful weight loss.
Also: Bioglutide, cyclic glycine-proline
NA-931 (Bioglutide) is cyclic glycine-proline, a two-amino-acid ring that occurs naturally as a breakdown product of IGF-1. Its developer, Biomed Industries, describes it as an oral once-daily agonist at four receptors at once - IGF-1, GLP-1, GIP and glucagon - and has reported 13 to 15 percent weight loss in a 126-person Phase 2 trial. Those numbers have only ever appeared in conference abstracts, never in a peer-reviewed paper, and no trial results have been filed to ClinicalTrials.gov. The same molecule is already sold as a consumer brain-health supplement and as a Sigma-Aldrich catalogue chemical, which makes it unusually cheap to source and unusually hard to verify.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | HGH Fragment 176-191 | NA-931 |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | This fragment is the C-terminal portion of growth hormone, the segment researchers identified as carrying its lipolytic (fat-breakdown) activity. In lab and animal work it stimulates fat cells to release and burn fat, increasing glycerol output and fat oxidation, apparently without binding the growth hormone receptor itself. That is the selling point: because it does not act on the GH receptor, it does not raise IGF-1, does not promote tissue growth, and does not impair glucose handling the way full growth hormone can. Some research points to involvement of beta-3 adrenergic signaling in fat tissue, though the exact human mechanism is not fully nailed down. | Cyclic glycine-proline is a diketopiperazine: glycine and proline joined into a small ring, 154 daltons, roughly a thirtieth the size of tirzepatide or retatrutide. The independent literature, mostly from Jian Guan's group in Auckland, describes a single mechanism: cGP competes with IGF-1 for binding to IGFBP-3, which frees up IGF-1 that was otherwise bound and inactive. That is a bioavailability effect, studied for stroke recovery, Parkinson's and blood pressure rather than for weight. Biomed's own patent filing (WO2025160184A1) goes much further, claiming the same molecule is a 'quadruple receptor agonist' at IGF-1, GLP-1, GIP and glucagon receptors. That claim is worth understanding properly, because it is the entire basis of the weight-loss story. GLP-1, GIP and glucagon receptors are class B GPCRs, the kind that normally need a thirty-plus residue peptide wrapping into the receptor's binding groove to switch on. A 154-dalton ring activating all three would be a genuinely significant pharmacological finding. No independent group has reported it. Searching PubMed for cyclic glycine-proline alongside GLP-1 returns nothing at all. |
| Common Dosing | 250-500 mcg daily 1-2x daily, fasted | 120 mg daily, oral Once daily |
| Administration | Subcutaneous injection on empty stomach | Oral capsule or tablet, once daily |
| Typical Duration | 8-12 weeks | 28 days in Phase 1, 13 weeks in Phase 2 |
| Best Time to Take | Before bed or morning (fasted) | Consistent daily timing |
Possible Side Effects May vary by individual |
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| Research Summary | The animal data looked promising and the human data deflated it, which is the whole story here. In obese mice (International Journal of Obesity, 2001), both growth hormone and AOD-9604 reduced body-weight gain and increased fat oxidation, without the blood-sugar problems of full GH. A small 12-week phase 2 human study generated the famous early headline, with the 1 mg group losing about 2.8 kg versus 0.8 kg on placebo. But the larger, better-powered phase 2b trial of roughly 500 obese adults over 24 weeks failed to show a significant weight-loss advantage over placebo, and the developer abandoned obesity development. What survived is the safety record: across about six trials and roughly 900 people, AOD-9604 was as well tolerated as placebo, with no IGF-1 rise and no glucose effects (Journal of Endocrinology and Metabolism, 2013). So it is safe and it does not work as a meaningful fat-loss drug in humans. | There are no peer-reviewed publications on NA-931. Not one. Everything in circulation is a conference abstract, and the abstracts carrying the efficacy numbers list Biomed's CEO as sole author with conflicts declared as 'None'. Two trials have completed, both run entirely in Australia: a 74-person Phase 1 (NCT06615700, completed September 2024) and a 126-person Phase 2 (NCT06564753, completed April 2025). Neither has results posted. A third trial (NCT06732245) would run in the US, Australia and New Zealand, but has not started recruiting. The reported weight loss is where this gets difficult. The same 126-person Phase 2 has been presented three times with three different numbers: 14.8 percent at ADA in June 2025, 13.8 percent at ENDO in July, and 13.8 percent with a different placebo-adjusted figure in a September press release. Enrolment is given as 125 in the abstracts against 126 on the registry. A result that moves between presentations is not yet a result. The company's website states NA-931 is in Phase 3. No Phase 3 trial for NA-931 is registered on ClinicalTrials.gov. The announcement traces to a single paid newswire release in January 2026, syndicated into around twenty local newspaper press-release sections, which reads like broad coverage but is one purchased placement. |
Frequently Asked Questions: HGH Fragment 176-191 vs NA-931
What is the difference between HGH Fragment 176-191 and NA-931?
HGH Fragment 176-191 is a weight loss peptide that hgh fragment 176-191 is exactly what it sounds like: a short tail-end piece of the human growth hormone molecule, amino acids 176 through 191. the idea was to keep the fat-burning part of growth hormone while ditching the parts that raise blood sugar and igf-1. the optimized drug version, aod-9604, actually went through real human trials for obesity, and the blunt result is that it was very safe but did not produce meaningful weight loss. NA-931 is a weight loss peptide that na-931 (bioglutide) is cyclic glycine-proline, a two-amino-acid ring that occurs naturally as a breakdown product of igf-1. its developer, biomed industries, describes it as an oral once-daily agonist at four receptors at once - igf-1, glp-1, gip and glucagon - and has reported 13 to 15 percent weight loss in a 126-person phase 2 trial. those numbers have only ever appeared in conference abstracts, never in a peer-reviewed paper, and no trial results have been filed to clinicaltrials.gov. the same molecule is already sold as a consumer brain-health supplement and as a sigma-aldrich catalogue chemical, which makes it unusually cheap to source and unusually hard to verify. The main differences lie in their mechanisms of action and clinical applications.
Which is better, HGH Fragment 176-191 or NA-931?
Neither is universally "better" - the choice depends on your specific goals. HGH Fragment 176-191 is typically used for weight loss purposes, while NA-931 is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can HGH Fragment 176-191 and NA-931 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using HGH Fragment 176-191 and NA-931 together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.