Reference/hGH C-terminal fragment (176-191)

HGH Fragment 176-191

Growth Hormone Fragment · Fat Loss Peptide

Animal in vivo

research use only

HGH Fragment 176-191 is the fat-burning segment of human growth hormone, corresponding to amino acids 176 through 191 of the full GH molecule. It stimulates lipolysis and inhibits lipogenesis without the growth-promoting or insulin-disrupting effects associated with full-length HGH. AOD-9604 is a modified version of this fragment with an added N-terminal tyrosine residue.

Stimulates lipolysis without growth hormone side effectsDoes not affect blood glucose or insulin sensitivityDoes not increase IGF-1 levelsSelectively targets fat metabolism

4 citations·0 with human data·Updated 10 Aug 2026

Overview

Mimics the lipolytic region of human growth hormone by stimulating fat breakdown through beta-3 adrenergic receptor pathways. Unlike full HGH, it does not bind the growth hormone receptor, so it does not increase IGF-1 levels or interfere with glucose metabolism. The fragment selectively targets adipose tissue to promote fat oxidation.

Evidence profilederived from 4 references

Animal in vivo

Strongest design among the references on this page. Grade and effect size are separate facts and are never merged into one score.

Research indications

What the compound has been studied for, grouped by body system. Effect size is the reported magnitude where it was measured — not a recommendation.

Fat Loss3

Lipolysis Enhancement

Increases fat oxidation and breakdown of stored triglycerides in adipose tissue without affecting glucose homeostasis.

Large

Lipogenesis Inhibition

Reduces new fat synthesis and storage, complementing the lipolytic action for overall fat reduction.

Moderate

Body Composition

Promotes selective fat loss while preserving lean mass, particularly effective when combined with a caloric deficit and exercise.

Moderate

A large effect in a weak study and a small effect in a strong one are different things. Effect size is never evidence of use in people.

Quick factsreference only

Class: hGH C-terminal fragment (176-191)
Chain length: 16 residues
Molecular weight: 1817.1 Da
Half-life: ~20 min
Typical dose: 250-500mcg
Frequency: Twice daily (fasted)
Cycle length: 8-12 weeks
Storage: Lyophilized: room temp or freezer long-term. Reconstituted: 2-8 degrees C for 28 days

Molecular data

Type: hGH C-terminal fragment (176-191)
Molecular weight: 1817.1 Da
Chain length: 16 residues
Half-life: 20 min

Primary sequenceN → C · 15 residues

H₂N–

LLeu1

RArg2

IIle3

VVal4

QGln5

CCys6

RArg7

SSer8

VVal9

EGlu10

GGly11

SSer12

CCys13

GGly14

FPhe15

–OH

LRIVQCRSVEGSCGF

NonpolarPolarAcidicBasic

Dosing reference

Doses reported in the literature and by suppliers. These are a record of what has been used in research — reference, never instruction.

Context	Route	Amount	Frequency
Fat loss - Standard	SubQ	250mcg	Twice daily (morning fasted + pre-bed)
Enhanced fat loss	SubQ	500mcg	Twice daily (morning fasted + pre-bed)
Conservative start	SubQ	250mcg	Once daily (morning, fasted)

Interactions

HGH

Redundant lipolytic mechanism. Full HGH already contains the 176-191 sequence, so combining provides diminishing returns for fat loss while adding HGH-related side effects.

monitor

AOD-9604

Same mechanism of action. AOD-9604 is a modified version of this fragment; using both is redundant and unnecessary.

avoid

Clenbuterol

Both target fat loss through complementary adrenergic pathways. The combination may enhance lipolysis beyond either compound alone.

synergistic

Quality checklist

✓White lyophilized powder with uniform appearance
✓Crystal clear solution without particles after reconstitution
✓Certificate of Analysis showing >98% purity by HPLC
✓Proper cold-chain shipping
!Not FDA approved - research chemical only
!WADA prohibited substance
×Discolored or clumped powder (yellow indicates degradation)
×Cloudy solution after reconstitution
×Collapsed or moisture-damaged appearance

What to expect

Week 1-2Minimal noticeable changes; fragment accumulating and establishing lipolytic signaling

Week 3-4Subtle improvements in fat loss, especially around the midsection with proper diet

Week 5-8More noticeable fat reduction and improved body composition with consistent use

Week 8-12Continued fat loss and body recomposition; most users run 8-12 week cycles

Safety

Commonly reported3

Injection site irritation (redness, mild swelling)
Headache, particularly in the first few days
Generally well-tolerated with a favorable safety profile

Stop and seek advice4

Severe injection site reactions or signs of infection
Hypoglycemia symptoms if combined with insulin (dizziness, sweating, confusion)
Allergic reactions (rare)
Any persistent or concerning symptoms

Contraindications3

Pregnancy or breastfeeding
Active cancer or history of malignancy
WADA prohibited - athletes subject to testing must avoid

FAQ

Is HGH Fragment 176-191 safe to use with insulin?

HGH Frag 176-191 does not affect blood glucose or insulin sensitivity directly, unlike full-length HGH. However, you should still monitor blood glucose if combining with insulin due to the fragment's lipolytic effects and the potential for unpredictable metabolic changes.

Can I combine HGH Fragment 176-191 with full-length HGH?

Not recommended. HGH already contains the 176-191 sequence, so adding the fragment provides redundant lipolytic action while increasing HGH-related side effects without proportional fat-loss benefit. Choose one or the other.

How quickly will I see fat loss from HGH Fragment 176-191?

Fat loss typically becomes noticeable around week 3-4 with proper diet and exercise. Weeks 5-8 show more significant reduction. Most users run 8-12 week cycles, with continued benefits observable through week 12.

Do I need to fast before injecting HGH Fragment 176-191?

Yes. Fasting is important for optimal effect. Inject on an empty stomach and wait at least 30 minutes before eating. Elevated insulin from food intake can suppress the lipolytic signaling that makes this fragment effective.

References

1
Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone
Ng FM, Jiang WJ, Gianello R, Pitt C, Heffernan M · Hormone Research · 2000
Characterized metabolic properties of AOD-9604 as a synthetic lipolytic domain of hGH with antilipogenic activity that does not interact with the GH receptor.
reviewPubMed 11146367 ↗
2
Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism
Heffernan MA, Heffernan MJ, Jiang WJ, Thorburn AW, Ng FM · American Journal of Physiology - Endocrinology and Metabolism · 2000
Oral treatment of ob/ob mice with AOD-9401 for 30 days significantly reduced body weight gain and altered lipogenic and lipolytic activity in adipose tissue.
animalPubMed 10950816 ↗
3
Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment
Heffernan MA, Thorburn AW, Fam B, Summers R, Conway-Campbell B, Waters MJ, Ng FM · International Journal of Obesity · 2001
Both hGH and AOD-9604 reduced body weight gain, increased fat oxidation, and stimulated lipolysis in obese ob/ob mice after 14 days chronic IP administration, without affecting glucose metabolism.
animalPubMed 11673763 ↗
4
The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice
Heffernan MA, Jiang WJ, Thorburn AW, Ng FM · Endocrinology · 2001
Both hGH and AOD-9604 increased repressed beta-3 adrenergic receptor RNA expression in obese mice to levels comparable with lean mice. Effects abolished in beta-3-AR knockout mice, confirming pathway involvement.
animalPubMed 11713213 ↗