HGH Fragment 176-191 is sold for fat loss in 2, 5 and 10 mg vials, with vendor pages giving figures in the hundreds of micrograms a day. None of those figures comes from a study of this peptide in people, because there is none. The single in-vivo study of this exact sequence is a 1978 rat experiment, and what it measured was a rise in blood sugar. This page sets out the record, converts the one published dose, and works the vendor figures into syringe units.
The compound itself — the sequence, the naming confusion and the evidence — is covered in Medibact's HGH Fragment 176-191 guide. The calculator's HGH Fragment setting works any vial and volume.
What has been published on this sequence
| Record | What it is | Dose |
|---|---|---|
| Ng and Bornstein, Am J Physiol 1978 (PMID 645904) | Six synthetic C-terminal fragments, 172-191 to 180-191, in normal rats | 5 nmol/kg for the insulin-tolerance tests |
| Drug Des Devel Ther 2022 (PMID 35783198) | The fragment attached to drug-carrying nanoparticles, tested against a breast-cancer cell line | none in animals or people |
| Two 2026 reviews (PMIDs 42395176, 41880199) | Performance-enhancing peptides in sport and bodybuilding | none of their own |
| ClinicalTrials.gov, DailyMed | — | no trial, no label (2026-09-26) |
In the 1978 study, fragments 172-191, 176-191, 177-191 and 178-191 each caused "a short-lived rise in blood glucose and a more sustained rise in plasma insulin", while 179-191 and 180-191 did nothing measurable. A single 5 nmol/kg dose of the fragments containing 178-191 reduced the rats' insulin sensitivity. That is the whole in-vivo record for 176-191 under its own number.
The 1978 dose, converted
The fragment weighs about 1,799 g/mol in its cyclised form (PubChem CID 16131230), so:
- 5 nmol/kg × 1,799 g/mol ≈ 9 mcg/kg in the rat.
- Scaled by body weight alone to 70 kg that would be about 630 mcg, which is inside the vendor range — but a rat dose given to test insulin sensitivity is not a human dose, and no conversion makes it one. The number is useful only to show how small the one studied amount was and what it was studied for.
Where the fat-loss claims come from
| Peptide | Relation to 176-191 | What was found | Where |
|---|---|---|---|
| hGH 177-191 | one residue shorter | suppressed new fat synthesis in rat fat tissue, no significant fat breakdown (1993); reduced weight gain and fat mass in obese mice (1994) | PMIDs 8358331, 7987248 |
| AOD-9604 | tyrosine in place of residue 176's phenylalanine | lower body weight and fat in obese mice after 14 days (2001); six human trials by mouth or vein, 2001-2006 | PMID 11713213; AOD-9604 dosage |
| hGH 176-191 | this compound | raised glucose and insulin in normal rats (1978) | PMID 645904 |
The human data belong to AOD-9604, and even those were never by injection under the skin. The two molecules share fifteen residues and differ at the first: phenylalanine in the natural hormone (UniProt P01241), tyrosine in AOD-9604 (PubChem CID 71300630, 1,815.1 g/mol). A label that gives AOD-9604's mass for a product sold as 176-191, or the reverse, describes a different molecule from its name.
The vendor figures
This site's peptide dosage chart, from vendor pages read on 2026-09-18 (one dated 2024-02-09), records 200 to 500 mcg under the skin, once or twice daily, in 4-week cycles. No trial, label or study stands behind those numbers.
| Vendor figure | Per day | 4-week cycle | 5 mg vial lasts |
|---|---|---|---|
| 250 mcg once daily | 250 mcg | 7 mg | 20 days |
| 500 mcg once daily | 500 mcg | 14 mg | 10 days |
| 500 mcg twice daily | 1,000 mcg | 28 mg | 5 days |
Units per vial
Units on a U-100 syringe = mcg ÷ mcg/mL × 100. Vials in this site's data come in 2, 5 and 10 mg:
| Amount | 2 mg + 2 mL (1,000 mcg/mL) | 2 mg + 1 mL (2,000 mcg/mL) | 5 mg + 2 mL (2,500 mcg/mL) | 10 mg + 2 mL (5,000 mcg/mL) |
|---|---|---|---|---|
| 200 mcg | 20 | 10 | 8 | 4 |
| 250 mcg | 25 | 12.5 | 10 | 5 |
| 300 mcg | 30 | 15 | 12 | 6 |
| 500 mcg | 50 | 25 | 20 | 10 |
The 2 mg and 5 mg vials look alike, and a figure carried from one to the other is off by a factor of 2.5; the mg to mcg page covers the conversion behind these rows and the insulin syringe units page the scale.
What is not established
No human study of hGH 176-191 exists — not its dose, its half-life, its effect on fat or its safety. The fat-metabolism findings belong to hGH 177-191 in rodents and to AOD-9604, and the one study of this sequence recorded raised glucose and insulin in rats. The vendor figures are reported, not endorsed; the conversions and unit figures are arithmetic. Nothing on this page is a dose or a schedule.
Sources and dates
Opened 2026-09-26: PubMed searches ('176-191' with growth hormone in title or abstract, 4 records; AOD9604 and hGH 177-191, 51 records) and abstracts for Ng and Bornstein, Am J Physiol 1978 (PMID 645904), Wu and Ng, Biochem Mol Biol Int 1993 (PMID 8358331), Natera, Jiang and Ng, Biochem Mol Biol Int 1994 (PMID 7987248) and Heffernan et al., Endocrinology 2001 (PMID 11713213); PubMed records 35783198, 42395176, 41880199 and 24124033 (titles); UniProt P01241 (human growth hormone sequence); PubChem CIDs 16131230 and 71300630; ClinicalTrials.gov and DailyMed searches; vendor figures as recorded on this site's dosage chart (read 2026-09-18). Conversions and unit figures are arithmetic by this site. Corrections go to the contact page.