HGH Fragment 176-191 vs Eloralintide
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: GSBR-1290, Structure GSBR-1290
Eloralintide (Eli Lilly code LY3841136) is an investigational, long-acting, selective amylin receptor agonist given as a once-weekly subcutaneous injection for obesity. Amylin is the satiety hormone your pancreas releases alongside insulin, and eloralintide is built to mimic it without the gut side effects that sink most appetite drugs. It is not approved anywhere yet, but it has cleared Phase 1 and a 263-person Phase 2 trial with weight loss up to roughly 20 percent, and Lilly has said it is moving into Phase 3.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | HGH Fragment 176-191 | Eloralintide |
|---|---|---|
| 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. | Amylin (also called IAPP) is a hormone co-secreted with insulin after you eat, and it tells your brain you are full and slows how fast your stomach empties. Eloralintide is engineered to selectively switch on the amylin receptor, which is the calcitonin receptor paired with a receptor-activity-modifying protein (RAMP), in appetite-control regions of the brainstem and hypothalamus. The result is reduced food intake and earlier satiety. The reason this class is interesting is that, unlike GLP-1 drugs such as semaglutide and tirzepatide, amylin agonists seem to drive weight loss with much less nausea and vomiting, which is what the eloralintide trials reported. Whether it preserves more lean mass than GLP-1 drugs is a real hypothesis being tested, not a settled fact. |
| Common Dosing | 250-500 mcg daily 1-2x daily, fasted | 120-240mg once daily (oral) Once daily |
| Administration | Subcutaneous injection on empty stomach | Oral tablet |
| Typical Duration | 8-12 weeks | 36 weeks in Phase 2 trials |
| Best Time to Take | Before bed or morning (fasted) | - |
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. | This is one of the few research peptides on this site with genuinely strong, recent human data. The Phase 1 proof-of-concept study (Eli Lilly, published 2026) randomized 100 adults with obesity across five ascending dose cohorts and reported dose-proportional pharmacokinetics and least-squares mean weight reductions of 2.6 to 11.3 percent by week 12, with notably low gastrointestinal side effects (nausea 8 percent, vomiting 4 percent). In November 2025 Lilly announced topline Phase 2 results in 263 adults with obesity or overweight: at 48 weeks all dose arms beat placebo, with mean weight loss from about 9.5 percent at the lowest dose up to 20.1 percent at 9 mg, versus 0.4 percent on placebo, plus improvements in waist circumference, blood pressure, lipids, and glycemic markers. The most common adverse events were mild-to-moderate nausea and fatigue. The honest caveat: full peer-reviewed Phase 2 data and any head-to-head against tirzepatide are still pending, and there are no long-term safety or cardiovascular outcome results yet because Phase 3 is only just beginning. So the early efficacy signal is impressive, but durability and long-term safety are unproven. |
Frequently Asked Questions: HGH Fragment 176-191 vs Eloralintide
What is the difference between HGH Fragment 176-191 and Eloralintide?
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. Eloralintide is a weight loss peptide that eloralintide (eli lilly code ly3841136) is an investigational, long-acting, selective amylin receptor agonist given as a once-weekly subcutaneous injection for obesity. amylin is the satiety hormone your pancreas releases alongside insulin, and eloralintide is built to mimic it without the gut side effects that sink most appetite drugs. it is not approved anywhere yet, but it has cleared phase 1 and a 263-person phase 2 trial with weight loss up to roughly 20 percent, and lilly has said it is moving into phase 3. The main differences lie in their mechanisms of action and clinical applications.
Which is better, HGH Fragment 176-191 or Eloralintide?
Neither is universally "better" - the choice depends on your specific goals. HGH Fragment 176-191 is typically used for weight loss purposes, while Eloralintide 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 Eloralintide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using HGH Fragment 176-191 and Eloralintide 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.