HGH Fragment 176-191

Areas of active research — not promised effects

Each tag links to other compounds with research into that goal. Research use only: these are areas of study, not human-use claims.

Related by research scope · open each to compare

HGH Fragment 176-191 has no FDA approval as a finished drug product and no IND or NDA on record. Unlike AOD-9604, it does not appear to have been placed on FDA's Category 2 bulk drug substances list for 503A compounding pharmacies. The April 2026 action (docket FDA-2025-N-6895) that removed 12 peptides from Category 2 did not involve this compound. Its absence from Category 2 does not indicate permissibility for compounding — it simply has no approved bulk drug substance status. Sale, distribution, and use are restricted to legitimate research and laboratory contexts (RUO). It is not approved for clinical, therapeutic, or human use.

Transparent blend · bci-1.0 · never paid-placement

Primary name

HGH Fragment 176-191

Origin

HGH Fragment 176-191 is the natural sequence of amino acids spanning positions 176 to 191 at the C-terminal end of the 191-amino-acid human growth hormone (hGH) polypeptide. This 16-residue sequence contains a disulfide bridge between two cysteine residues and was identified as the region of hGH responsible for much of its fat-mobilizing (lipolytic) activity, distinct from the growth-promoting N-terminal domain. The unmodified fragment differs from the closely related research compound AOD-9604 in that it lacks the additional N-terminal tyrosine residue added to improve stability and bioavailability in the AOD-9604 derivative. HGH Fragment 176-191 carries PubChem CID 172966176, molecular formula C80H127N23O24S2 (as acetic acid salt), and InChIKey OFBOQPIYGYREOZ-LWAQQTRHSA-N. No regulatory authority has approved it as a therapeutic product, and it has not been evaluated in human clinical trials.

Registry IDs

PubChem CID

172966176

InChIKey

OFBOQPIYGYREOZ-LWAQQTRHSA-N

Molecular formula

C80H127N23O24S2

Molar mass

1859.1 g/mol

Monoisotopic

1857.8865744 Da

InChIKey

OFBOQPIYGYREOZ-LWAQQTRHSA-N

Appearance

White to off-white lyophilized powder (vendor-typical; not from certified reference standard data)

Solubility

Soluble in water and dilute acetic acid (0.1–1% acetic acid); limited solubility…

Sequence not available in current seed.

Stability: The intramolecular disulfide bridge (between cysteine residues in the cyclic region of the fragment) is susceptible to oxidative degradation; reducing agents in

Vial sizes

2 mg · 5 mg

Purity grades

≥98% HPLC

Salt forms

Free base (primary)

• GHS hazard class on file
• PPE & spill response
• Disposal guidance
• Not-for-human-consumption posture

How much research exists, and of what maturity — never a verdict on whether it works.

Mechanism of action

• The C-terminal hGH fragment is proposed to stimulate lipolysis in adipocytes by engaging the beta-3 adrenergic receptor (β3-AR) pathway, upregulating hormone-sensitive lipase (HSL) activity to mobilize stored triglycerides
• Research in obese rodent models using the closely related AOD-9604 (Tyr-hGH 177-191) demonstrated that lipolytic effects were abolished in β3-AR knockout animals, implicating this receptor as a primary mediator; these findings are commonly extrapolated to the unmodified fragment, though direct mechanistic validation in independent studies of hGH 176-191 itself is limited
• The fragment does not appear to bind the canonical growth hormone receptor and is not reported to elevate circulating IGF-1 or promote somatogenic growth in the preclinical models examined
• A 2022 in vitro study (PMID 35783198) explored an unrelated application, demonstrating that hGH fragment 176-191 enhanced cytotoxicity of doxorubicin-loaded chitosan nanoparticles against MCF-7 breast cancer cells in molecular docking and cell-viability assays, suggesting possible utility as a cancer drug-delivery component

Pharmacokinetics (ADME)

Half-life

Approximately 2–3 hours (subcutaneous, estimated from vendor and secondary sources; no peer-reviewed PK study identified for the unmodified fragment)

Clearance

Presumed rapid proteolytic clearance; no formal pharmacokinetic characterization published for hGH 176-191 as distinct from AOD-9604

PK–PD note: No peer-reviewed human or formal animal PK study specific to the unmodified hGH Fragment 176-191 has been identified. Published PK data pertain to AOD-9604 (Tyr-hGH 177-191), a structurally distinct a…

Reading the evidence

• Evidence quality and gaps vary by application — see the cited grades above.
• Indexed-article counts span all evidence tiers, not only completed human trials.
• No first-party human-dosing, efficacy, or benefit claims are made here.

Key reviews & evidence-gap sources

• Wilding J. AOD-9604 Metabolic. Curr Opin Investig Drugs. 2004;5(4):436-40. PMID 15134286 — Review of AOD9604 (modified derivative of hGH 176-191) metabolic/obesity program; pre-CTG-registration era.
• Rahman OF, Lee SJ, Seeds WA. Therapeutic Peptides in Orthopaedics. J Am Acad Orthop Surg Glob Res Rev. 2026;10(1):e25.00236. PMID 41490200 — Recent review covering peptide therapeutics in orthopaedics; references AOD9604/fragment 176-191.
• Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026. PMID 41966639 — Review addressing unapproved peptide therapies including growth hormone fragments.
• Wikipedia: HGH Fragment 176–191 — Aggregator/secondary source; explicitly states hGH frag 176-191 has not been studied in humans (only AOD9604 has).

No registered human trials found for this compound.

Status

No registered trials found

Summary (literature)

No standalone human safety trials have been conducted for the unmodified hGH Fragment 176-191. The available safety context derives from the closely related AOD-9604, for which approximately 900 participants across six clinical safety studies were reported to show a generally fav…

WADA status

Prohibited at all times (in-competition and out-of-competition) under the WADA 2026 Prohibited List, Section S2 (Peptide Hormones, Growth Factors, Related Subst…

Dominant research route: Subcutaneous injection is the dominant community-reported route for fragment 176-191 (Layer B, anecdotal); the only cited human clinical-route data (IV infusion and oral tablets) are for the AOD9604 analog, not fragment 176-191 itself.

Phase I double-blind, placebo-controlled dose-escalation safety study (METAOD001) and a subsequent study (METAOD002) of the AOD9604 analog (Tyr-hGH 177-191) in healthy adult male volunteers, BMI 24-30 kg/m²; single escalating IV doses 25-400 µg/kg

Bioavailability: Intravenous infusion; bioavailability by definition ~100% for the AOD9604 analog. No IV pharmacokinetic data published for fragment 176-191 itself.

The only cited human IV data are for AOD9604 (the N-terminal tyrosine-stabilized analog of hGH 177-191), not fragment 176-191. A single IV dose of recombinant hGH (0.12 IU/kg) was used as a positive control in METAOD001.

Phase 2b randomized, double-blind, placebo-controlled trial of AOD9604 administered as oral tablets once daily at dose groups of 0, 0.25, 0.5 and 1 mg; plus additional oral capsule/tablet studies summarized in the Stier 2013 safety review (six RCTs total, several oral)

Bioavailability: AOD9604 is described in the literature as an 'orally active' lipolytic peptide fragment; the N-terminal tyrosine substitution was intended to stabilize the peptide for oral delivery. No oral bioavailability data exist for fragment 176-191 itself.

Oral route was studied only for the AOD9604 analog, not fragment 176-191. Development of AOD9604 was halted following poor efficacy in a later 24-week trial. Oral peptide delivery remains challenging; this is an oral-stability observation, not an oral-absorption claim for fragment 176-191.

No validated human pharmacokinetic studies of fragment 176-191 via subcutaneous injection; SC use is reported in de-identified community/research-chemical contexts and aggregator guidance

Bioavailability: No peer-reviewed human SC bioavailability data for fragment 176-191. Aggregator sources assert peak plasma levels within ~30-45 minutes and half-life ~2-3 hours, but these are not traceable to a primary human PK study of fragment 176-191.

SC is the dominant community-reported route for fragment 176-191, but published clinical studies of the related AOD9604 analog employed IV infusion and oral tablets rather than SC injection. Treat SC PK claims as unsourced community data.

Intra-articular injection of AOD9604 (with or without hyaluronic acid) in a rabbit osteoarthritis model

Bioavailability: Local joint-space administration in an animal model; no systemic bioavailability characterization. No human intra-articular data.

Cited animal study is for the AOD9604 analog in a rabbit OA model, not fragment 176-191 in humans.

Animal & human figures are kept visibly separate so studied animal doses are never misread as human guidance.

Sorted A–Z by vendor — never by price

Weekly median $/mg from the live vendor crawl.

Researched storefront prices, bucketed

p25 $9.70 · median $10.67 · p75 $15.96 · 9 researched vendors

Legit, COA-backed band: $8.20–$12.00/mg.

Value rule: don't just buy the cheapest — a price under $3/mg is a red flag. Pair price with COA and independent-test grade.

Estimated cost of research (10 mg)

Vial (best researched price)

$82

Bacteriostatic water (generic estimate)

$6

Syringes / supplies (generic estimate)

$12

What each test proves — general guidance, plus this compound's researched purity data

Purity on the current market (researched)

Vendor-reported purity ranges from ≥98% to ≥99% by HPLC (e.g., PeptidePowerUS lists 'not less than 98%'; QSC Peptides and PuraPeptides claim ≥99%). These are seller-reported values accompanied by third-party COAs (Janoshik cited by QSC); no independent non-voucher lab aggregate was located for this specific compound.

Independent labs cited for this compound

No recalls specific to HGH Fragment 176-191 were found in FDA enforcement reports, CBP notices, or DOJ filings. The compound is not an FDA-approved drug product; recalls typically apply to approved/marketed products. None found.

Buyer red-flag checklist

• Not FDA-approved for any use; no approved BLA or NDA covers HGH Fragment 176-191
• Wikipedia notes the compound 'has not been studied in humans' and lipolytic claims are 'erroneously presented' based on extrapolation from AOD9604 (a modified derivative)
• Sold through unregulated research-chemical channels; vendor purity claims (98–99%) are self-reported with vendor-commissioned COAs, not independent surveillance
• FDA Import Alert 66-71 flags unapproved HGH products (including lyophilized powders) for DWPE; criminal penalties up to 5–10 years under 21 U.S.C. 333(e)(1)
• CBP reported 67 HGH/steroid shipments seized in a single Chicago operation (Mar 2025), most from Hong Kong via master-carton smuggling
• DOJ prosecuted peptide sellers (Gavin Burns Smith, 2015) for misbranding bodybuilding peptides not FDA-approved for human use
• No published human clinical trials; all efficacy claims derive from animal/in-vitro data or extrapolation from AOD9604

GMP vs research-grade: the chemistry (SPPS + HPLC + MS) is identical — the difference is the quality system.

Underdosing / mislabeling: No independent lab-test aggregate (Janoshik/MZ Biolabs/Finnrick) reporting underdosing prevalence specific to HGH Fragment 176-191 was located. General peptide-market underdosing/contamination concerns are widely noted but not quantified for this compound.

• Detention Without Physical Examination of Unapproved Human Growth Hormone (HGH). Covers unapproved HGH finished dosage forms including lyophilized powders for reconstitution; firms on Red List subject to DWPE. Applies to HGH products generally; HGH Fragment 176-191 is an HGH-derived peptide fragment sold in the same unapproved lyophilized-powder channel.FDA Import Alert 66-71
• An RUO label is not an import exemption — CBP judges actual intended use.
• Lyophilized powder is ambient-stable in transit; temperature control needed for > 7-day transit.
• US-warehouse vendors dodge import scrutiny — they cost more but ship more reliably.

Every item dated & sourced

Prohibited at all times (in- and out-of-competition) under S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics), explicitly named as 'growth hormone fragments, e.g. AOD-9604 and hGH 176-191'. Classified as a non-specified substance.

No granted patents identified in current seed. Composition-of-matter coverage is limited given the peptide's synthetic origin.

• IACUC / IRB research context
• RUO buyer responsibilities & documentation
• Veterinary / alternative-use where lawful
• Jurisdiction-aware "who may lawfully obtain"

What people discuss

Reported concerns — discussion, not established effects

Reading caveats

• Self-experimentation community — efficacy self-reports uncontrolled
• Vendor-affiliated posters present in forums
• Concomitant compound use confounds self-reports
• Wikipedia editorial flags erroneous extrapolation from AOD9604 clinical data

Manually researched from reddit, youtube— theme weights are research estimates, not live counts; aggregated & de-identified. No individual posts, quotes, or usernames are ever shown.

Relative research / market volume — populated once the activity stream is wired

Inline tooltips for lyophilized, RUO, EU/mg, SPPS, 503A and more.

Toggle plain-language ↔ scientific in the header.

• How to read a COA
• Free base vs acetate
• Understanding evidence grades

Unmodified C-terminal fragment (residues 176–191) of human growth hormone studied in vitro and in animal models for lipolytic and anti-cancer drug-delivery applications. Approximately 1 articles are indexed (literature last scanned 2026-05-29). US regulatory status: No FDA approval; not on Category 2 list; RUO only. Research use only.

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