HGH Fragment 176-191

Supported

HGH Fragment 176-191 is the unmodified C-terminal 16-amino-acid segment corresponding to residues 176 through 191 of human growth hormone. It must remain separate from AOD-9604, full-length somatropin, growth-hormone-releasing peptides, GHRH analogues, and unspecified "HGH fragment" products. AOD-9604 is a chemically modified analogue derived from the growth-hormone C-terminal region; its sequence begins with an added or substituted tyrosine rather than the native phenylalanine found at residue 176 of hGH, making it a different molecular entity. Marketplace use of "AOD-9604," "HGH Frag," "Frag 176-191," and "hGH 177-191" as synonyms is scientifically unreliable. Free peptide, cyclic/disulfide status, acetate or TFA salts, terminal modifications, and vendor-specific sequences must not be assumed equivalent without analytical verification.

Sources: PubChem HGH Fragment 176-191 Record; A synthetic peptide corresponding to the C-terminal sequence of human growth hormone inhibits lipogenesis in rat adipose tissue

Supported

No FDA-approved drug containing HGH Fragment 176-191 was identified. FDA-approved somatropin products do not authorize or validate isolated HGH Fragment 176-191. No reviewed human interventional trial specifically administering unmodified HGH Fragment 176-191 was identified.

Sources: FDA Import Alert 66-71: Human Growth Hormone

Supported

The 2026 WADA Prohibited List explicitly names hGH 176-191 as a prohibited growth-hormone fragment under section S2.2.3. Anti-doping prohibition is separate from FDA approval and clinical evidence.

Supported

No published controlled human efficacy, pharmacokinetic, repeated-dose safety, or dose-ranging study of unmodified HGH Fragment 176-191 was identified. Human obesity studies frequently attributed online to "HGH Fragment 176-191" involved AOD-9604, a different modified molecule; those data cannot establish efficacy or safety of the unmodified fragment, oral/subcutaneous/nasal bioavailability, a validated consumer dose, or equivalence to AOD-9604. Full-length human growth hormone studies likewise cannot be transferred to the isolated fragment.

Sources: PubChem HGH Fragment 176-191 Record; FDA Import Alert 66-71: Human Growth Hormone

Supported

A 2022 study evaluated hGH Fragment 176-191 as part of a chitosan-nanoparticle formulation combined with doxorubicin against MCF-7 breast-cancer cells. This was an in-vitro drug-delivery experiment; it did not administer the peptide to humans and does not establish cancer treatment, fat loss, metabolic benefit, systemic safety, standalone peptide efficacy, or efficacy of ordinary lyophilized marketplace material.

Sources: HGH Fragment 176-191 in Doxorubicin-Loaded Chitosan Nanoparticles

Supported

Popular lipolysis and anti-lipogenesis claims are largely extrapolated from older growth-hormone fragment research, animal studies, AOD-9604 development, and full-length GH physiology. Direct human evidence for unmodified HGH Fragment 176-191 was not identified.

Sources: PubChem HGH Fragment 176-191 Record; HGH Fragment 176-191 in Doxorubicin-Loaded Chitosan Nanoparticles

Supported

The fragment is marketed as avoiding the growth-promoting effects of full-length GH. No adequate human study establishes that unmodified HGH Fragment 176-191 does not affect IGF-1, cannot affect glucose regulation, lacks proliferative effects, is safer than somatropin, or produces selective fat loss. Absence of full-length GH receptor activity has not been clinically established for marketplace products.

Sources: FDA Import Alert 66-71: Human Growth Hormone

Supported

FDA's Pharmacy Compounding Advisory Committee briefing on CJC-1295-related bulk drug substances also documented marketplace products combining growth-hormone-fragment materials with other compounded peptides. This regulatory context does not establish an FDA-sanctioned combination product or human efficacy/safety for HGH Fragment 176-191.

Sources: FDA CJC-1295 PCAC Briefing Document

Supported

Human safety is unknown. Important concerns include incorrect substitution of AOD-9604 evidence, uncertain sequence/disulfide configuration/salt/purity, aggregation and peptide-related impurities, immunogenicity and anti-drug antibodies, sterility and endotoxin risks, unknown pharmacokinetics and tissue distribution, unknown glucose/insulin/lipid/hepatic effects, unknown IGF-axis and growth-signaling effects, unknown cardiovascular/renal/reproductive/oncologic effects, unknown interaction with diabetes/cancer/pituitary disease/exogenous GH, and lack of repeated-dose, pregnancy, pediatric, and long-term data.

Sources: FDA Import Alert 66-71: Human Growth Hormone; HGH Fragment 176-191 in Doxorubicin-Loaded Chitosan Nanoparticles

Supported

WADA-sponsored analytical work has documented mislabeled performance-enhancing peptide products, including a vial labeled HGH Frag 176-191 that contained a different peptide. This illustrates product-identity risk rather than the safety of authentic material.

Sources: WADA Research on Detection and Identification of Peptide Products

Supported

Animal studies of synthetic hGH C-terminal fragments reported inhibition of lipogenesis and reductions in weight gain or adipose mass in obese mice.

Sources: A synthetic peptide corresponding to the C-terminal sequence of human growth hormone inhibits lipogenesis in rat adipose tissue

Supported

Native hGH 177-191 fragment-family preclinical research includes a 2000 oral-administration lipid-metabolism study (PMID 10950816) and modern context from a 2026 GH-IGF1-axis performance-peptide review (PMID 42395176). These are treated as fragment-family evidence, not as AOD-9604-brand efficacy evidence, consistent with this page's existing separation from AOD-9604.