Comparison

HGH Fragment 176-191 vs Cagrilintide

Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research

HGH Fragment 176-191

Also: Frag 176-191, HGH Frag

Clinical Trials

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.

Weight LossHuman Trials
Cagrilintide

Also: AM833, NN9838

Clinical Trials

Cagrilintide (also called AM833) is a long-acting synthetic analog of amylin, the gut-brain satiety hormone co-secreted with insulin by pancreatic beta cells. It is an investigational once-weekly injectable being developed by Novo Nordisk for obesity, most prominently as the amylin half of CagriSema (cagrilintide plus semaglutide). It is not yet approved as a standalone drug, but it has cleared phase 2 trials and is in late-stage development.

Weight LossHuman Trials

Key Comparison Insights

  • Both peptides belong to the Weight Loss category, suggesting similar primary applications.

Detailed Comparison

AttributeHGH Fragment 176-191Cagrilintide
CategoryWeight LossWeight Loss
FDA StatusNot FDA ApprovedNot FDA Approved
Clinical Status
Pre
I
II
III
IV
FDA
Pre
I
II
III
IV
FDA
Mechanism of ActionThis 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.Cagrilintide is a non-selective agonist of the amylin and calcitonin receptor family. It activates amylin receptors (which are calcitonin receptors paired with RAMP accessory proteins) to signal satiety in the brain, slow gastric emptying, and blunt the post-meal glucagon rise. Mechanistic work in mice shows it reduces body weight mainly through amylin receptors AMY1R and AMY3R acting in the hindbrain, with the area postrema as a key entry point and downstream signaling through the nucleus of the solitary tract and parabrachial nucleus. Notably, weight loss in those studies persisted even after the acute appetite-suppressing effect faded, hinting at effects on energy balance beyond simple food-intake reduction. Chemically it is built on a pramlintide-like 37-amino-acid backbone with substitutions and a fatty-diacid chain attached to extend its half-life to roughly a week, enabling once-weekly dosing.
Common Dosing
250-500 mcg daily
1-2x daily, fasted
2.4 mg weekly
Once weekly
AdministrationSubcutaneous injection on empty stomachSubcutaneous injection once weekly
Typical Duration8-12 weeksLong-term / chronic use expected
Best Time to TakeBefore bed or morning (fasted)Any consistent time weekly
Possible Side Effects
May vary by individual
  • Generally well-tolerated
  • Injection site reactions
  • Mild headache
  • Nausea
  • Does NOT cause typical HGH side effects
  • +2 more
  • Nausea (common, usually transient)
  • Vomiting
  • Diarrhea
  • Constipation
  • Abdominal pain
  • +6 more
Research SummaryThe 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.Cagrilintide has real human data, which sets it apart from most peptides in this category. In a 2021 Lancet phase 2 dose-finding trial (Lau et al.), once-weekly cagrilintide at 4.5 mg produced about 10.8% mean body weight loss over 26 weeks, beating both placebo (around 3%) and liraglutide 3.0 mg (around 9%), establishing that amylin agonism alone can drive clinically meaningful weight loss. Its bigger story is combination therapy: paired with semaglutide as CagriSema, it advanced into phase 3 REDEFINE trials for obesity and type 2 diabetes, with reported weight loss in the low 20% range, though final results came in somewhat below the most optimistic expectations. Side effects are dominated by the expected gastrointestinal effects (nausea, vomiting) common to gut-hormone drugs. As of 2026 cagrilintide is investigational and not FDA-approved on its own. The evidence is genuinely human and well-controlled here, which is rare, but it is still a drug under regulatory review rather than an approved therapy.

Frequently Asked Questions: HGH Fragment 176-191 vs Cagrilintide

What is the difference between HGH Fragment 176-191 and Cagrilintide?

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. Cagrilintide is a weight loss peptide that cagrilintide (also called am833) is a long-acting synthetic analog of amylin, the gut-brain satiety hormone co-secreted with insulin by pancreatic beta cells. it is an investigational once-weekly injectable being developed by novo nordisk for obesity, most prominently as the amylin half of cagrisema (cagrilintide plus semaglutide). it is not yet approved as a standalone drug, but it has cleared phase 2 trials and is in late-stage development. The main differences lie in their mechanisms of action and clinical applications.

Which is better, HGH Fragment 176-191 or Cagrilintide?

Neither is universally "better" - the choice depends on your specific goals. HGH Fragment 176-191 is typically used for weight loss purposes, while Cagrilintide 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 Cagrilintide be used together?

Some peptide protocols combine multiple compounds for synergistic effects. However, using HGH Fragment 176-191 and Cagrilintide 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.

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