# Fragment 176-191 — dosage, half-life & reference guide

Source: https://pepvault.app/peptides/fragment-176-191

Last updated: 2026-09-26

[Library](https://pepvault.app/peptides) [Growth hormone](https://pepvault.app/peptides#growth-hormone) reviewed September 2026

# Fragment 176-191 Dosage, half-life & reference guide

Also known as HGH Fragment 176-191 · HGH Frag · AOD Fragment

A stabilized fragment of the growth hormone molecule (amino acids 176-191), usually sold as the same peptide as AOD-9604. It targets fat cells: in rodents it boosted fat breakdown without affecting blood sugar or IGF-1.

- **Studied range:** 250–500 mcg
- **How often:** Daily
- **Half-life:** ~30 min
- **Evidence:** Moderate
- **Route:** SubQ injection

Studied in research — not a recommendation.

[Fragment 176-191 dose guide](https://pepvault.app/lab/dosage/fragment-176-191)

## How it works.

Stabilized fragment of HGH amino acids 176-191, usually the same peptide as AOD-9604 (hGH 177-191 with an added tyrosine). Boosts fat breakdown (rodent studies) without affecting blood glucose or IGF-1 levels; in obese mice it raised beta-3 receptor levels rather than binding them directly.

**Commonly reported:** Subtle at best, with many users noticing little and some describing slow fat loss with fasted morning dosing and a diet, plus mild injection-site redness. Human trials (as AOD-9604) found modest weight loss at best.

## Where Fragment 176-191 works.

- ### Appetite & metabolism

  **In animals.** It targets fat cells: in rodents it boosted fat breakdown without affecting blood sugar or IGF-1.

An area lights for what a peptide is used for and what people report, with the evidence beside it. It isn’t a promise that it works there.

## Week by week.

What to expect in the first 8 weeks

1. Day 1–14 Community

   ### No GH effects to feel

   Fragment 176-191 is different from the other GH peptides: it keeps the fat-regulating tail of HGH but drops the GH signaling. Commonly reported: no change in sleep or hunger, and at most a slow drift of body fat down, usually with fasted dosing and a diet.

   The science

   Frag 176-191 acts on fat cells without using the GH receptor (mouse studies) — no IGF-1 rise, no insulin resistance, no pituitary feedback. It isn't a beta-3 agonist: in obese mice it raised beta-3 receptor levels instead (Heffernan 2001). Wu & Ng 1993 showed the 177-191 tail blocks fat synthesis; fat-release effects were reported later (Ng et al. 2000). Many dose fasted because insulin dampens fat release; no study has tested timing.

   Sources

   - Wu & Ng (1993)
   - Heffernan et al. (2001)
   - Ng et al. (2000)

   Updated Sep 2026
2. Day 14–56 Community

   ### A slow drift, for some users

   Commonly reported, for those who respond: a subtle body-composition drift with the split-dose, fasted protocol. Users find it works best layered on an existing cut, not as a standalone.

   The science

   In obese rats, the fragment halved weight gain and shrank fat cells (Ng et al. 2000). Human data come from the same peptide under the name AOD-9604: six small trials, with modest weight loss in a 12-week trial and none in a larger 24-week trial.

   Sources

   - Ng et al. (2000)
   - Stier et al. (2013)

   Updated Sep 2026
3. Day 56–112 Community

   ### Plateau is a real thing here

   Commonly reported: a plateau around 8–12 weeks, and why isn't known. Cycling off 4–6 weeks or rotating to a different fat-loss approach is the conservative community play; continuing through a plateau rarely breaks it.

   The science

   Beta-3 receptor desensitization doesn't explain the plateau: the fragment isn't a beta-3 agonist, and in mice it raised beta-3 receptor levels (Heffernan 2001). No human chronic-dosing data exist. Community protocols have settled on 12-week cycles with breaks based on observed diminishing returns.

   Sources

   - Heffernan et al. (2001)

   Updated Sep 2026
4. Any day Animal

   ### What Fragment 176-191 is built on

   Good mechanistic story — the fat-regulating tail of HGH without the growth signaling — and solid animal data. Human data come from the same peptide sold as AOD-9604, where the larger trial failed. Treat it as a subtle fat tool layered into an existing cut, not a standalone fix.

   The science

   Wu & Ng at Monash University showed the C-terminal 177-191 tail blocks fat synthesis (1993). AOD-9604 (Metabolic Pharmaceuticals) was the commercial version and reached phase 2b in obesity before discontinuation. Frag 176-191 is the research-grade equivalent, usually the identical peptide. No major harms were reported in the published animal studies, but formal toxicology data aren't public, and FDA lists AOD-9604 in compounding category 2, citing a possible risk of immune reactions.

   Sources

   - Wu & Ng (1993)
   - Ng et al. (2000)

   Updated Sep 2026

Day 1 is the day you start it.

## Mixing and a typical run.

Example numbers

### Reconstitution example

Reconstitute a 5 mg vial of Fragment 176-191 with 2 mL of bacteriostatic water and a 375 mcg dose is 15 units on a U-100 syringe, about 13 doses per vial.

- **Vial:** 5 mg
- **Water:** 2 mL
- **Amount:** 375 mcg

Draw to **15 units**

0.3 mL insulin syringe · 30 units

[Mix it in the Reconstitution Lab](https://pepvault.app/lab) [Open the calculator](https://pepvault.app/tools/reconstitution-calculator)

### Run notes

- **Cycle:** 12–16 weeks. Often cycled alongside CJC/Ipa stack. Plateau reported; cycling advised. Community practice — opinions vary. Not a clinical recommendation.
- **Timing:** Fasted injection, ideally morning; many split it into 2 daily doses (community practice).
- **Route:** SubQ injection
- **Stacks:** CJC-1295 no DAC, Ipamorelin

## Safety.

### Common side effects

- Injection site reactions
- Generally well tolerated
- Mild flushing

## Goes with.

- [CJC-1295 no DAC](https://pepvault.app/peptides/cjc-1295-no-dac)
- [Ipamorelin](https://pepvault.app/peptides/ipamorelin)

## Compared with.

- [AOD-9604 vs Fragment 176-191](https://pepvault.app/peptides/compare/aod-9604-vs-fragment-176-191)

## Questions people ask.

### What is Fragment 176-191?

A stabilized fragment of the growth hormone molecule (amino acids 176-191), usually sold as the same peptide as AOD-9604. It targets fat cells: in rodents it boosted fat breakdown without affecting blood sugar or IGF-1.

### How is Fragment 176-191 dosed in research?

The research range for Fragment 176-191 is 250–500 mcg. Daily, split into 2 doses, fasted. Studied in research — not a recommendation.

### How long does Fragment 176-191 last?

The half-life of Fragment 176-191 is ~30 min.

### What do people report on Fragment 176-191?

Commonly reported on Fragment 176-191: subtle at best, with many users noticing little and some describing slow fat loss with fasted morning dosing and a diet, plus mild injection-site redness. Human trials (as AOD-9604) found modest weight loss at best.

### Is Fragment 176-191 safe?

The research basis for Fragment 176-191 is moderate: animal studies + some human data. Common side effects in the library: injection site reactions, generally well tolerated and mild flushing.

### What does Fragment 176-191 stack with?

Common stacks for Fragment 176-191: CJC-1295 no DAC and Ipamorelin.

## Research.

The literature

### Search the latest research

[PubMed](https://pubmed.ncbi.nlm.nih.gov/?term=Fragment%20176-191) [Google Scholar](https://scholar.google.com/scholar?q=Fragment%20176-191)

## Reference.

- **Cadence:** Daily Daily, split into 2 doses, fasted
- **Half-life:** ~30 min
- **Research basis:** Moderate Animal studies + some human data

## More growth hormone peptides

- [IGF-1 LR3 20–50 mcg](https://pepvault.app/peptides/igf-1-lr3)
- [PEG-MGF 200–400 mcg](https://pepvault.app/peptides/peg-mgf)
- [Follistatin-344 100–200 mcg](https://pepvault.app/peptides/follistatin-344)
- [HGH 1–4 IU](https://pepvault.app/peptides/hgh)
- [CJC-1295 with DAC 1–2 mg](https://pepvault.app/peptides/cjc-1295-with-dac)
- [Sermorelin 200–500 mcg](https://pepvault.app/peptides/sermorelin)

## Free tools

- [Fragment 176-191 dose guide](https://pepvault.app/lab/dosage/fragment-176-191)
- [Reconstitution Lab (3D)](https://pepvault.app/lab)
- [Injection guide (3D)](https://pepvault.app/lab/injection)
- [Peptide Sky (3D)](https://pepvault.app/lab/sky)
- [Peptide tier list](https://pepvault.app/lab/tiers)
- [Reconstitution calculator](https://pepvault.app/tools/reconstitution-calculator)
- [Half-life & active level](https://pepvault.app/tools/peptide-half-life-calculator)

PepVault for iPhone

## Track Fragment 176-191 in PepVault

Log every dose and keep your vial and the doses left in it. 7 days free on the yearly plan for new subscribers.

[Download on the App Store](https://apps.apple.com/app/apple-store/id6779318649?pt=129020030&ct=peptides-cta&mt=8)

[Open the calculator](https://pepvault.app/tools/reconstitution-calculator) [How the vial count works](https://pepvault.app/peptide-vial-tracker-app) [Explore the live demo](https://pepvault.app/login)

Reviewed September 2026 [How we check the library](https://pepvault.app/about#library)

PepVault is a research and tracking resource, not medical advice. Ranges are what studies used, never a dose for you. Brand names are trademarks of their owners; PepVault is independent of them.

PepVault is a private research and tracking tool, not medical advice. The information here is reference material from published literature and community use — always verify it and discuss any protocol with a qualified clinician before changing it.

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