AOD-9604 vs AOD9604: The Same Peptide, Different Names
The notation confusion isn't trivial. Researchers contacting suppliers, reviewing study protocols, or cross-referencing published literature routinely encounter both 'AOD-9604' and 'AOD9604' and reasonably wonder whether the hyphen signals a structural difference, purity grade variation, or distinct peptide altogether. Here's what matters: the hyphen is a formatting convention only. Both terms refer to the identical 15-amino-acid C-terminal fragment (residues 177–191) of human growth hormone. The peptide's amino acid sequence, molecular weight (1815.08 Da), and mechanism remain unchanged regardless of how the identifier is written.
Our team sources peptides across dozens of suppliers annually. The naming inconsistency appears most frequently when comparing European regulatory filings (which favour 'AOD-9604') with supplier catalogues and research protocols published outside standardised nomenclature systems (which often drop the hyphen). The peptide itself doesn't change. The identifier does.
What's the difference between AOD-9604 and AOD9604?
There is no chemical, structural, or functional difference between AOD-9604 and AOD9604. Both names refer to the same synthetic peptide fragment. A modified version of amino acids 177–191 from the C-terminus of human growth hormone. The hyphen is a typographic convention adopted by some manufacturers and researchers but absent in others. The sequence, purity specifications, and biological mechanism are identical.
The Naming Convention Isn't Indicating Different Peptides
The peptide sequence underlying both identifiers is fixed: Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly. This 15-residue chain represents the lipolytic domain isolated from human growth hormone. The region responsible for fat mobilisation without affecting glucose metabolism or insulin sensitivity. Whether a supplier labels it 'AOD-9604', 'AOD9604', 'AOD 9604', or even 'fragment 177-191 hGH' doesn't alter the molecular structure. The peptide's mechanism. Stimulation of hormone-sensitive lipase and inhibition of lipoprotein lipase in adipocytes. Remains constant across all naming formats.
We've analysed certificate-of-analysis documents from multiple 503B-registered facilities supplying this peptide for research purposes. The mass spectrometry data, HPLC purity readings (typically ≥98%), and amino acid composition reports are indistinguishable whether the vial label reads 'AOD-9604' or 'AOD9604'. The variation is purely administrative.
The hyphenated format appears more frequently in formal regulatory submissions and peer-reviewed publications citing Metabolic Pharmaceuticals' original development nomenclature from the late 1990s. The non-hyphenated version proliferates in supplier catalogues, research forums, and peptide databases where typographic simplification is standard. Neither format is 'correct' or 'official'. The peptide community uses both interchangeably without implying any distinction in the underlying compound.
Why the Confusion Exists Across Suppliers and Publications
The naming inconsistency originates from the peptide's development history. AOD-9604 was synthesised by Metabolic Pharmaceuticals (now defunct) in the 1990s as part of a broader program to isolate hGH's lipolytic effects while eliminating its diabetogenic and mitogenic properties. Early publications and patent filings used 'AOD-9604' with a hyphen. A convention that stuck in academic circles. When the peptide entered broader research use through peptide synthesis companies and compounding facilities, many suppliers dropped the hyphen for database compatibility and simplified cataloguing.
Another layer: research-grade peptide suppliers frequently assign their own internal product codes (e.g., 'RP-AOD9604' at Real Peptides) that may or may not retain the original hyphen. The Chemical Abstracts Service (CAS) registry number for this peptide. 221231-10-3. Remains constant, but supplier SKU formats vary widely. Researchers cross-referencing between a journal article citing 'AOD-9604' and a supplier listing 'AOD9604' sometimes interpret the discrepancy as indicating different compounds when they're purchasing the identical molecule.
The situation parallels other peptide nomenclature inconsistencies: BPC-157 vs BPC157, TB-500 vs TB500, or Selank vs Selanc. The peptide science community has never standardised punctuation conventions for research designations that aren't formal INN (International Nonproprietary Name) entries. Until such standardisation occurs. If it ever does. Both 'AOD-9604' and 'AOD9604' will continue appearing interchangeably across research literature, supplier catalogues, and clinical protocols.
What Researchers Should Verify Beyond the Name
The naming format is irrelevant to peptide quality or suitability for a given study. What matters: amino acid sequencing confirmation, purity grade (≥95% for most applications, ≥98% for critical studies), lyophilisation method, and storage conditions. Every batch of research-grade AOD-9604. Regardless of how the label spells it. Should ship with a certificate of analysis documenting HPLC purity, mass spectrometry results confirming molecular weight (1815.08 Da ±0.5 Da), and bacterial endotoxin testing showing <1 EU/mg.
We've encountered situations where researchers requested 'AOD-9604 without the hyphen' from suppliers, believing it represented a newer synthesis method or higher purity grade. It doesn't. The peptide synthesis process. Solid-phase peptide synthesis (SPPS) using Fmoc chemistry, followed by purification via reverse-phase HPLC. Is identical for both naming conventions. If a supplier claims the non-hyphenated version is 'improved' or 'more bioavailable', they're misrepresenting the product.
Another verification point: reconstitution protocol. AOD-9604 (or AOD9604) typically ships as lyophilised powder requiring reconstitution with bacteriostatic water before use. The standard concentration is 2 mg peptide per vial, reconstituted to 2 mL for a final 1 mg/mL solution. This protocol applies universally. The hyphen doesn't change solubility, stability, or recommended storage temperature (2–8°C post-reconstitution, <−20°C in lyophilised form).
AOD-9604 / AOD9604: Research Applications Comparison
| Application Context | Key Mechanism | Typical Protocol | Research Limitation | Professional Assessment |
|---|---|---|---|---|
| Lipolysis / Fat Mobilisation Studies | Stimulates hormone-sensitive lipase in adipocytes; inhibits lipoprotein lipase to reduce triglyceride storage | 250–500 mcg subcutaneous injection daily for 8–12 weeks in rodent models | Human trials (Metabolic Pharmaceuticals Phase 2b, 2007) showed no statistically significant weight loss vs placebo despite mechanistic promise | Strong preclinical mechanistic data; human efficacy underwhelming. Best suited for mechanistic lipolysis research rather than weight-loss endpoints |
| Cartilage Repair / Osteoarthritis Models | Derived from hGH's C-terminus; may stimulate chondrocyte proliferation without systemic IGF-1 elevation | Intra-articular injection 1–2 mg weekly in animal models; no established human dosing | No published human clinical trials on cartilage outcomes; all evidence is preclinical or anecdotal | Mechanistically plausible but entirely unproven in humans. Research-only compound |
| Metabolic Research (Insulin-Independent) | Does not bind hGH or IGF-1 receptors; preserves lipolytic effect without hyperglycaemic or mitogenic risk | Same dosing as lipolysis studies; paired with glucose tolerance testing to confirm insulin neutrality | The very feature that makes it 'safer' than hGH (no IGF-1 activation) also limits its anabolic potential | Useful negative control in hGH studies; demonstrates that lipolysis can be uncoupled from growth pathways |
| Injury Recovery (Soft Tissue) | Hypothesised to support collagen synthesis and fibroblast activity via non-IGF-1 pathways | 250–500 mcg daily subcutaneous; duration 4–8 weeks in soft tissue injury models | All injury recovery claims are extrapolated from hGH data or anecdotal reports. No dedicated AOD-9604 injury trials exist | High mechanistic speculation; no direct evidence yet. Better-studied peptides (BPC-157, TB-500) have stronger injury-repair datasets |
Key Takeaways
- AOD-9604 and AOD9604 are the same peptide. The hyphen is a typographic convention only, not a chemical distinction.
- Both names refer to a 15-amino-acid fragment (residues 177–191) of human growth hormone's C-terminus, with molecular weight 1815.08 Da.
- Metabolic Pharmaceuticals originally used 'AOD-9604' with a hyphen in 1990s patent filings; suppliers later dropped it for simplified cataloguing.
- The peptide's amino acid sequence (Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly), purity specifications, and lipolytic mechanism are identical regardless of naming format.
- Verification matters more than naming: always request a certificate of analysis showing HPLC purity ≥98%, mass spectrometry confirmation, and endotoxin testing <1 EU/mg.
- Human weight-loss trials (2007 Phase 2b) showed no statistically significant fat loss vs placebo despite strong preclinical lipolysis data.
What If: AOD-9604 / AOD9604 Scenarios
What If a Supplier Lists Both 'AOD-9604' and 'AOD9604' as Separate Products?
Request certificates of analysis for both SKUs and compare the amino acid sequence data. If the molecular weight, HPLC purity, and sequence match exactly. And they should. The supplier is selling the same peptide under two catalogue entries, likely for database or SEO purposes. This isn't fraudulent but it's administratively redundant. Choose whichever listing has the clearer documentation or better unit pricing. If the supplier claims they're functionally different, ask for the specific structural difference in writing. There isn't one.
What If a Research Protocol Specifies 'AOD-9604' But Your Supplier Only Stocks 'AOD9604'?
Proceed without concern. The compounds are identical. The protocol author used the hyphenated format because that's how the original Metabolic Pharmaceuticals literature spelled it, but the peptide's activity doesn't depend on punctuation. Verify that the supplier's product matches the sequence (residues 177–191 hGH) and purity grade (≥95% minimum, ≥98% preferred). If those align, the absence of a hyphen in the product name is irrelevant to experimental outcomes.
What If You're Comparing Published Studies Using Different Name Formats?
Treat them as referencing the same compound. A 2005 paper citing 'AOD-9604' and a 2018 supplier whitepaper referencing 'AOD9604' are discussing the identical peptide fragment. The naming inconsistency complicates literature searches. PubMed and Google Scholar will return different result sets depending on whether you include the hyphen. But doesn't indicate different molecules. When conducting systematic reviews, search both terms separately and de-duplicate results manually.
The Blunt Truth About AOD-9604 Naming and Efficacy
Here's the honest answer: the naming debate distracts from a more fundamental issue. AOD-9604's human efficacy data is weak. The peptide demonstrates robust lipolytic activity in rodent adipocytes and in vitro assays, but Metabolic Pharmaceuticals' 2007 Phase 2b trial in 300 obese adults showed no statistically significant weight loss compared to placebo after 12 weeks at 1 mg daily subcutaneous dosing. The peptide works mechanistically. It activates hormone-sensitive lipase and inhibits fat storage enzymes. But those effects didn't translate to meaningful body composition changes in controlled human trials.
That doesn't make AOD-9604 useless for research. It remains valuable as a tool for studying lipolysis pathways independent of growth hormone's other effects, particularly its insulin resistance and IGF-1 elevation. The peptide proves that hGH's fat-mobilisation function can be isolated from its diabetogenic properties. A finding with implications for metabolic disease research. What it hasn't proven is that isolating that function produces clinically relevant weight loss in humans.
The cartilage repair claims are even thinner. Early speculation suggested AOD-9604 might stimulate chondrocyte activity without systemic IGF-1 elevation, making it 'safer' than full hGH for joint applications. No published human trials support that hypothesis. The peptide's inclusion in some joint health stacks is speculative at best. Researchers exploring cartilage repair mechanisms have better-documented peptides available. BPC-157 has far more robust injury and repair data, and even that compound lacks Phase 3 human efficacy trials.
Every peptide in research-grade supply exists on a spectrum between 'mechanistically proven' and 'clinically validated'. AOD-9604 sits firmly in the former category. It works in the lab. It hasn't worked in people. That's not a naming issue. It's an efficacy issue.
The notation variation you're researching. 'AOD-9604' with a hyphen versus 'AOD9604' without. Is a formatting artefact from the peptide's transition out of pharmaceutical development and into research supply channels. Both names describe the same 15-amino-acid fragment with the same molecular weight, purity standards, and mechanism of action. The hyphen appears in early Metabolic Pharmaceuticals patents and academic citations; it disappears in supplier catalogues and modern research protocols where simplified nomenclature is standard. Neither format is more 'official' than the other.
What determines quality isn't the name format. It's the synthesis method, purity verification, and handling. Real Peptides synthesises every batch using solid-phase peptide synthesis with Fmoc protection, followed by reverse-phase HPLC purification to ≥98% purity. Every vial ships with third-party mass spectrometry confirmation, amino acid analysis, and bacterial endotoxin testing. Whether the label reads 'AOD-9604' or 'AOD9604' on the supplier's website, the peptide in the vial is the same molecule. And the documentation proves it.
Frequently Asked Questions
Is AOD-9604 with a hyphen a different peptide from AOD9604 without one?▼
No — they’re the exact same peptide. The hyphen is a typographic convention that appeared in Metabolic Pharmaceuticals’ original patent filings and early research publications. Some suppliers retain it; others drop it for simplified cataloguing. The amino acid sequence (residues 177–191 of human growth hormone), molecular weight (1815.08 Da), and biological mechanism are identical regardless of punctuation.
Why do some research papers use ‘AOD-9604’ and others use ‘AOD9604’?▼
Early academic publications and regulatory filings from Metabolic Pharmaceuticals used ‘AOD-9604’ with a hyphen. As peptide synthesis companies and research suppliers adopted the compound, many dropped the hyphen for database compatibility and simplified SKU formatting. Neither version is ‘official’ — the peptide community uses both interchangeably, and the underlying molecule remains unchanged.
Can I use AOD9604 in a study protocol that specifies AOD-9604?▼
Yes — they’re the same compound. Verify that your supplier’s product matches the required amino acid sequence (Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly) and purity grade (≥95% minimum, ≥98% for critical applications). If those specifications align with your protocol requirements, the absence of a hyphen in the product name has no bearing on experimental validity or peptide function.
Does the hyphen indicate higher purity or a newer synthesis method?▼
No. The hyphen is purely a naming convention with no relationship to synthesis method, purity grade, or bioavailability. Peptide quality is determined by HPLC purity (≥98% is standard for research-grade AOD-9604), mass spectrometry confirmation of molecular weight, and proper lyophilisation and storage. If a supplier claims the hyphenated or non-hyphenated version represents improved quality, they’re misrepresenting the product.
What should I verify when purchasing AOD-9604 or AOD9604 for research?▼
Request a certificate of analysis documenting HPLC purity (≥98%), mass spectrometry results confirming molecular weight 1815.08 Da (±0.5 Da), amino acid sequencing confirmation, and bacterial endotoxin testing showing <1 EU/mg. The peptide should ship as lyophilised powder requiring reconstitution with bacteriostatic water. Storage should be <−20°C in powder form and 2–8°C after reconstitution. These specifications matter far more than whether the label includes a hyphen.
Are there any functional differences in how AOD-9604 vs AOD9604 should be reconstituted or stored?▼
No. Both names refer to the same peptide, so reconstitution and storage protocols are identical. Standard practice: reconstitute 2 mg lyophilised powder with 2 mL bacteriostatic water for a 1 mg/mL solution. Store reconstituted peptide at 2–8°C and use within 28 days. Store unreconstituted powder at <−20°C to preserve stability. The naming format doesn't alter solubility, stability, or handling requirements.
Why does a PubMed search for ‘AOD-9604’ return different results than a search for ‘AOD9604’?▼
PubMed and other academic databases treat hyphenated and non-hyphenated terms as distinct search strings. Early publications (late 1990s to mid-2000s) predominantly used ‘AOD-9604’ because that’s how Metabolic Pharmaceuticals formatted it. More recent supplier whitepapers and informal research reports often drop the hyphen. When conducting systematic reviews or literature searches, query both terms separately and manually de-duplicate results.
Did Metabolic Pharmaceuticals ever produce two versions of this peptide with different names?▼
No. Metabolic Pharmaceuticals developed one peptide — AOD-9604 (with hyphen) — as part of their hGH fragment research program. The company never produced a ‘non-hyphenated version’ or variant peptide. The naming inconsistency emerged later when peptide synthesis companies and research suppliers catalogued the compound under simplified formats. There was only ever one peptide; the notation diverged in commercial and research contexts.
Is AOD-9604 proven effective for weight loss in humans?▼
No. A 2007 Phase 2b trial by Metabolic Pharmaceuticals in 300 obese adults found no statistically significant weight loss with AOD-9604 compared to placebo after 12 weeks at 1 mg daily subcutaneous dosing. The peptide demonstrates robust lipolytic activity in preclinical models — it stimulates hormone-sensitive lipase and inhibits fat storage — but those effects didn’t translate to meaningful body composition changes in controlled human studies.
Can AOD-9604 support cartilage repair or joint health?▼
The evidence is entirely preclinical and speculative. Early hypotheses suggested AOD-9604 might stimulate chondrocyte activity without elevating systemic IGF-1, making it theoretically ‘safer’ than full hGH for joint applications. No published human trials support this claim. The peptide’s inclusion in some joint health research protocols is based on mechanistic speculation, not clinical validation. Researchers exploring cartilage repair have better-documented peptides with stronger injury and repair datasets.
What is the CAS registry number for AOD-9604, and does it change based on the hyphen?▼
The CAS registry number is 221231-10-3, and it remains the same whether the peptide is written as ‘AOD-9604’ or ‘AOD9604’. CAS numbers are unique identifiers assigned to specific molecular structures, not naming conventions. If a supplier lists a different CAS number for what they claim is AOD-9604 or AOD9604, you’re looking at a different compound entirely — request clarification and documentation before proceeding.
How does AOD-9604 compare to full-length human growth hormone for lipolysis?▼
AOD-9604 isolates the lipolytic (fat-mobilising) effect of hGH’s C-terminal region without activating IGF-1 pathways or affecting glucose metabolism. This makes it non-diabetogenic and non-mitogenic, unlike full hGH which elevates blood glucose and stimulates cell proliferation. However, the same feature that makes it ‘safer’ also limits its anabolic potential — it doesn’t build muscle or improve recovery the way hGH does. In research contexts, AOD-9604 is useful for studying lipolysis independently from hGH’s other systemic effects.
