HGH Fragment 176-191 (HGH Frag)

Growth Hormone Fragment | Fat Loss Peptide

Weight: 1,817.1 Da
Half-life: 15-20 minutes
Chain: 16 amino acids
4 studies
2001 latest
1 recent
Moderate Research
Dose 250-500mcg
Frequency Twice daily (fasted)
Cycle 8-12 weeks
Storage Lyophilized: room temp or freezer long-term. Reconstituted: 2-8 degrees C for 28 days
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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.

Mechanism of Action

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.

01 Stimulates lipolysis without growth hormone side effects
02 Does not affect blood glucose or insulin sensitivity
03 Does not increase IGF-1 levels
04 Selectively targets fat metabolism
05 No impact on bone or organ growth

Molecular Data

Molecular Weight
1,817.1 Da
Chain Length
16 amino acids
Type
hGH C-terminal fragment (176-191)
Amino Acid Sequence
One-letter: LRIVQCRSVEGSCGF
H₂N
L 1
O ‖ C
N
R 2
O ‖ C
N
I 3
O ‖ C
N
V 4
O ‖ C
N
Q 5
O ‖ C
N
C 6
O ‖ C
N
R 7
O ‖ C
N
S 8
O ‖ C
N
V 9
O ‖ C
N
E 10
O ‖ C
N
H
G 11
O ‖ C
N
S 12
O ‖ C
N
C 13
O ‖ C
N
H
G 14
O ‖ C
N
F 15
COOH
Leu
1

Leucine

Position 1

Arg
2

Arginine

Position 2

Ile
3

Isoleucine

Position 3

Val
4

Valine

Position 4

Gln
5

Glutamine

Position 5

Cys
6

Cysteine

Position 6

Arg
7

Arginine

Position 7

Ser
8

Serine

Position 8

Val
9

Valine

Position 9

Glu
10

Glutamic Acid

Position 10

Gly
11

Glycine

Position 11

Ser
12

Serine

Position 12

Cys
13

Cysteine

Position 13

Gly
14

Glycine

Position 14

Phe
15

Phenylalanine

Position 15

N-terminus C-terminus
Hydrophobic
Polar
Positive (+)
Negative (-)
Modified
Peak 0.0 mcg
Trough 0.0 mcg
SS Peak 0.0 mcg
SS Trough 0.0 mcg

Research Indications

Fat Loss
Lipolysis Enhancement most effective

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

Lipogenesis Inhibition effective

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

Body Composition effective

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

Dosing Protocols

Subcutaneous injection is the standard route. Best administered twice daily on an empty stomach -- once in the morning and once before bed. Avoid eating for at least 30 minutes after injection for optimal fat-burning effect.

GoalDoseFrequencyRoute
Fat loss - Standard250mcgTwice daily (morning fasted + pre-bed)SubQ
Enhanced fat loss500mcgTwice daily (morning fasted + pre-bed)SubQ
Conservative start250mcgOnce daily (morning, fasted)SubQ

Reconstitution Instructions

Materials Needed:
  • Lyophilized HGH Frag 176-191 vial
  • Bacteriostatic water (BAC water)
  • Insulin syringes (0.5-1mL)
  • Alcohol swabs
  • Sterile work surface
  1. 1 Allow vial to reach room temperature (15-20 minutes)
  2. 2 Calculate required bacteriostatic water volume
  3. 3 Clean vial stopper with alcohol swab
  4. 4 Draw BAC water into syringe
  5. 5 Inject slowly down vial side (not directly onto powder)
  6. 6 Gently swirl until dissolved (never shake vigorously)
  7. 7 Store reconstituted solution at 2-8 degrees C
  8. 8 Use within 28 days

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

What to Expect

Week 1-2
Minimal noticeable changes; fragment accumulating and establishing lipolytic signaling
Week 3-4
Subtle improvements in fat loss, especially around the midsection with proper diet
Week 5-8
More noticeable fat reduction and improved body composition with consistent use
Week 8-12
Continued fat loss and body recomposition; most users run 8-12 week cycles

Side Effects & Safety

Common Side Effects

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

Stop Signs - Discontinue if:

  • 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

Contraindications

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

Quality Checklist

Good Signs

  • 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

Warning Signs

  • Not FDA approved - research chemical only
  • WADA prohibited substance

Bad Signs

  • Discolored or clumped powder (yellow indicates degradation)
  • Cloudy solution after reconstitution
  • Collapsed or moisture-damaged appearance

References

  • 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 the C-terminal fragment (176-191) reduced body weight gain, increased fat oxidation, and stimulated lipolysis in obese ob/ob mice without affecting glucose metabolism.

  • 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)

    The hGH fragment and its modified form AOD-9604 both increased beta-3 adrenergic receptor expression in obese mice. Effects were abolished in beta-3-AR knockout mice, confirming this receptor pathway is essential for the lipolytic action.

  • 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 the metabolic properties of the hGH 176-191 lipolytic domain, demonstrating antilipogenic activity independent of the growth hormone receptor.

  • 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 with the synthetic hGH fragment for 30 days significantly reduced body weight gain and altered lipogenic and lipolytic activity in adipose tissue of obese mice.

Disclaimer

This information is for educational and research purposes only. Consult a healthcare professional before use.