HGH Fragment 176-191: 5MG

£24.99

Purity: ≥ 99%

£24.99

HGH Fragment 176-191: 5MG

Name: HGH Fragment 176-191: 5MG
Brand: Pure Grade Labs
Price: 24.99 GBP
Availability: OutOfStock

£24.99

Purity: ≥ 99%

£24.99

LIPOLYSIS MECHANISMS - Fat breakdown & antilipogenic activity research

GH FRAGMENT - Targeted fat loss & IGF-1 independent research

METABOLIC SELECTIVITY - Fat loss without growth hormone side effects research

COMPARATIVE FRAGMENT STUDIES - Fragment variant & compound selectivity research

HGH Fragment 176-191 is a synthetic 16-amino acid peptide corresponding to the C-terminal region of human growth hormone - specifically residues 176 through 191 of the native 191-amino acid hGH sequence. It retains the original phenylalanine at the N-terminus (unlike AOD-9604, which substitutes tyrosine at this position). The peptide contains a disulfide bridge between the two cysteine residues at positions 7 and 14 of the fragment sequence, mirroring a structural feature of the same region in full-length hGH.

The research hypothesis underlying this fragment is that the C-terminal region of hGH is the domain primarily responsible for the hormone's lipolytic (fat-metabolising) activity, while other regions mediate its growth-promoting and diabetogenic effects. By isolating this fragment, researchers have investigated whether selective fat-metabolising activity can be achieved without the IGF-1 elevation, insulin resistance, and cell-proliferative effects associated with full-length hGH administration. In preclinical rodent models using the closely related fragment AOD-9604, this selectivity was partially supported.

Structural Context: The native phenylalanine-initiated fragment (176-191) of hGH. Distinct from AOD-9604, which uses tyrosine at the N-terminus. Contains a disulfide bridge (Cys7-Cys14) critical to structural integrity. 16 amino acids, 1,799.1 g/mol. Not tested in humans as of April 2026.

Evidence Level: Preclinical only. Direct studies on hGH Fragment 176-191 are sparse. The majority of mechanistic understanding is inferred from AOD-9604 (Tyr-modified) research. Researchers should treat these as related but distinct compounds and not assume full pharmacological equivalence.

Amino Acid Sequence: H-Phe-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe-OH | Disulfide bridge: Cys(7)-Cys(14)

Molecular Formula: C₇₈H₁₂₃N₂₃O₂₂S₂

Molecular Weight: 1,799.1 g/mol

CAS Number: 66004-57-7

Form: Lyophilised Solid

Direct peer-reviewed studies on HGH Fragment 176-191 are limited. The following includes both studies directly investigating the 176-191 fragment and key studies on AOD-9604 (the closely related Tyr-modified version) that are commonly referenced to contextualise Fragment 176-191 research. Distinctions between the two compounds are noted explicitly. Pure Grade Labs does not extrapolate AOD-9604 findings as direct evidence for Fragment 176-191.

Biochemistry and Molecular Biology International: Antilipogenic action of synthetic C-terminal sequence 176-191 of hGH

American Journal of Physiology - Endocrinology & Metabolism: Lipolytic effects of hGH C-terminal fragment in obese mice: beta-3 adrenergic receptor mechanism [AOD-9604 data]

Endocrinology: Selective lipolytic activity of growth hormone C-terminal fragments: differential effects on glucose metabolism

References

https://pubmed.ncbi.nlm.nih.gov/35783198/

https://pmc.ncbi.nlm.nih.gov/articles/PMC9249349/

https://pubmed.ncbi.nlm.nih.gov/11673763/

https://pubmed.ncbi.nlm.nih.gov/10950816/

https://pubmed.ncbi.nlm.nih.gov/11713213/

https://pubmed.ncbi.nlm.nih.gov/7987248/

https://pubmed.ncbi.nlm.nih.gov/8358331/

https://pubmed.ncbi.nlm.nih.gov/645904/

https://pubmed.ncbi.nlm.nih.gov/25208511/

Every batch of HGH Fragment 176-191 supplied by Pure Grade Labs is accompanied by a Certificate of Analysis (COA) from an independent third-party analytical laboratory. Given the structural similarity between Fragment 176-191 and AOD-9604, mass spectrometry confirmation of the correct Phe-initiated sequence (not Tyr) is included in all batch documentation to confirm compound identity. The disulfide bridge integrity is also confirmed by MS.

HGH Fragment 176-191 is supplied as a lyophilised solid. Like AOD-9604, this fragment contains a disulfide bridge between Cys(7) and Cys(14) that is integral to structural integrity. Handling protocols are identical to those for AOD-9604: non-reducing reconstitution conditions must be maintained, and the peptide's half-life in solution is approximately 2-3 hours in vivo, necessitating careful experimental timing if activity persistence is relevant to the protocol.

Temperature: -20°C Long-term storage. For short-term use (up to 4 weeks), 2-8°C is acceptable.

Light Sensitivity: Light-Sensitive. Store in original opaque vial. Avoid direct UV or prolonged exposure to light.

Shelf Life: 24 Months. Lyophilized, sealed, stored at -20°C. Batch expiry printed on vial label.

Allow the sealed vial to reach room temperature before opening to minimise moisture introduction.
Use bacteriostatic water (BAC water) as the reconstitution solvent. Add solvent slowly down the inside wall of the vial. Use only non-reducing buffers - never use DTT, beta-mercaptoethanol, or other reducing agents as these will cleave the critical Cys(7)-Cys(14) disulfide bridge.
Gently swirl until fully dissolved. Do not vortex. The peptide dissolves readily in aqueous solution at room temperature.
Once reconstituted, store at 2-8°C. Use within 28 days. Avoid repeated freeze-thaw cycles of reconstituted solution, which can compromise the disulfide bond.
Discard if solution appears cloudy, discoloured, or contains particulate matter.

HGH Fragment 176-191 supplied by Pure Grade Labs is intended exclusively for in vitro research and laboratory use. This compound has not been evaluated in human clinical trials and has not received regulatory approval for any therapeutic use from the FDA, MHRA, TGA, EMA, or any other authority.

This product is not a drug, medicine, or supplement and must not be used as such.
Pure Grade Labs makes no claims regarding therapeutic or clinical efficacy in humans. Published human clinical data commonly attributed to this compound actually pertains to AOD-9604, a structurally related but chemically distinct Tyr-modified peptide.
This product must not be administered to humans or animals outside of a licensed research context.
HGH Fragment 176-191 is classified as a prohibited substance by the World Anti-Doping Agency (WADA). Athletes subject to drug testing must not use this compound.
Purchasers are solely responsible for compliance with all applicable laws and regulations in their jurisdiction before ordering.

All product information, research summaries, and study citations presented on this page are provided for informational context only and do not constitute medical advice, endorsement of any treatment, or recommendation for human use.