Metabolic & Fat Loss

HGH Fragment 176-191

Also known as: HGH Frag, Fragment 176-191

Molecular Identifiers

Molecular Formula

C80H127N23O24S2

CAS Number

66004-57-7

PubChem CID

172966176

Molecular Weight

1817.12 Da

Overview

Synthetic peptide corresponding to amino acids 176-191 of human growth hormone. Promotes lipolysis without effect on insulin or IGF-1.

The main clinical interest around HGH Fragment 176-191 is its selective lipolytic effect: it stimulates triglyceride breakdown in adipose tissue and inhibits lipogenesis, without the systemic effects of full-length GH on insulin, IGF-1, or tissue growth. This profile makes it attractive in fat-loss protocols, especially for stubborn abdominal fat, without the risk of insulin resistance or unwanted hypertrophy.

HGH Fragment 176-191 currently has no regulatory approval from any agency (FDA, EMA, ANVISA). It is most often dispensed by compounding pharmacies as off-label use, in cycles of 12 weeks or more, with subcutaneous administration fasted or pre-cardio. WADA lists GH fragments as substances prohibited at all times for competitive athletes.

Among GH fragments, it is most often compared with AOD 9604: both derive from the C-terminal portion of GH and aim to isolate the lipolytic effect without the anabolic effects of the whole hormone, but HGH Frag 176-191 is the unmodified native sequence, while AOD 9604 is a version with an added N-terminal tyrosine (Tyr-hGH 177-191) that provides greater stability.

Sequence (1 letter): FLRIVQCRSVEGSCGF
Extended notation: Phe-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe

Half-life

~30 minutes

Administration Route

Subcutaneous

Category

Metabolic & Fat Loss

Mechanism of Action

  • Direct lipolysis in adipose tissue
  • No effect on insulin or IGF-1
  • Inhibition of lipogenesis
  • No anabolic activity on muscle tissue

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter Value
Dose 250-500 mcg per injection
Frequency 1-2 times per day
Timing Morning fasted, pre-cardio
Duration 12+ weeks

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

  • Injection site pain
  • Local redness
  • Mild headache
  • Hypoglycemia (rare)

Product Properties

Purity >98%
Appearance White lyophilized powder
Solubility Soluble in water and bacteriostatic water
Source Solid-phase peptide synthesis (SPPS)
Storage Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles.

Presentations & Preparation

Vials of HGH Fragment 176-191 found in the research market:

5 mg10 mg

Reconstitution

  • Diluent: Bacteriostatic water
  • Volume: 2 ml per vial
  • Inject the diluent slowly against the vial wall
  • Gently swirl until fully dissolved
  • Never shake

Storage

  • Lyophilized: Refrigerated 2-8°C
  • Reconstituted: Refrigerated 2-8°C (up to 30 days)
  • Protect from direct light
  • Do not freeze after reconstitution
Reconstitution Calculator

Scientific Studies

Published studies on HGH Fragment 176-191.

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