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Educational reference only. Nothing on this page constitutes medical advice or encourages personal use of this compound. Always consult a qualified healthcare provider before any decision involving your health.
HGH Fragment 176-191 · Frag 176-191 in the community
AOD-9604 has the cleanest safety record in this book and the most direct clinical evidence against its primary claimed application. Both of those facts deserve equal weight.
The central tension resolved: AOD-9604 was designed specifically, explicitly, and professionally to produce human fat loss. Metabolic Pharmaceuticals ran six clinical trials involving more than 900 participants to prove it worked. The pivotal trial failed to demonstrate the primary endpoint. The company terminated development. WADA banned it. The FDA in December 2024 declined to allow it to be legally compounded. The community is using it for fat loss — the exact application it failed to demonstrate — at doses below the doses that failed, in a population completely different from the obese patients who were studied, using a route (SubQ injection) that wasn't even tested in the pivotal trials. The community use of AOD-9604 for fat loss is among the most evidence-unsupported applications in this entire book.
This is not to say AOD-9604 is dangerous — it is among the safest injectable peptides in existence by clinical trial evidence. It is to say that 'safe' and 'effective for fat loss' are different claims, and the evidence for the latter is negative at the clinical trial level. Community users may experience subjective effects or attribute fat loss to AOD-9604 that is actually resulting from improved diet, training, or other compounds in the stack. The absence of proven efficacy does not mean the compound does nothing — it means the controlled evidence doesn't support the primary marketing claim.
The most honest application for AOD-9604 in 2026: the cartilage and joint health application, where the animal data is consistent, the route (local or systemic injection) is more appropriate than oral, and the clinical evidence gap is due to incomplete investigation rather than a failed pivotal trial. For users with osteoarthritis or significant joint damage interested in regenerative approaches, AOD-9604 has a more defensible scientific rationale than for fat loss in lean athletes.
Growth hormone does two things that are pharmacologically useful and two things that are pharmacologically problematic. The useful: it burns fat (lipolysis) and it builds lean mass (anabolism). The problematic: it raises IGF-1 (which at high levels promotes cancer growth) and it disrupts glucose metabolism (causing insulin resistance at pharmacological doses). The premise of AOD-9604's entire development program was simple and elegant: what if you could take only the fat-burning part?
Professor Frank Ng at Monash University in Melbourne worked from the structural biology of human growth hormone. hGH is a 191-amino acid protein whose different functional properties — growth promotion, fat mobilization, metabolic effects — are mediated by different regions of the molecule. The C-terminal region (approximately amino acids 176-191) had been associated with lipolytic activity in laboratory studies. Ng's hypothesis was that a peptide corresponding to this region — with a tyrosine substituted at the N-terminus for synthetic stability — would retain GH's fat-burning properties while lacking its receptor-binding capacity and all the downstream effects that flow from GH receptor activation.
The structural rationale was sound. AOD-9604 (the internal designation 'Anti-Obesity Drug 9604' becoming its permanent name) was synthesized and characterized. In animal models, it performed as designed: it increased fat oxidation, reduced adipose tissue, and did so without raising IGF-1 or affecting growth parameters. The animal evidence was genuinely encouraging — multiple independent animal studies confirmed the lipolytic effects, including in obese mouse models. Metabolic Pharmaceuticals was formed to develop it commercially, and a clinical trial program was launched in the late 1990s.
The clinical program was impressive in scope. Six trials over approximately a decade, eventually enrolling more than 900 participants. The compound demonstrated one thing consistently across every trial: it was safe. Safety profile indistinguishable from placebo. No IGF-1 elevation. No glucose dysregulation. No tissue growth. No unexpected adverse events. AOD-9604 is, by the evidence, one of the safest injectable peptides ever evaluated in human trials. Whether this reflects its genuine inertness at doses studied, or merely the short trial durations, is a separate question — but the safety record is real and extensive.
The efficacy story is more complicated. Early Phase II trials at 1 mg/day oral dosing showed modest but statistically significant weight loss compared to placebo — approximately 2.6 kg vs 0.8 kg at 12 weeks in one trial. The pharmaceutical development logic was straightforward: if 1 mg shows a signal, confirm it in a larger, longer trial at optimized doses. This was the OPTIONS Study — a Phase IIb randomized, double-blind, placebo-controlled trial enrolling 536 obese participants for 24 weeks, with a primary endpoint of weight loss at 12 weeks. The trial was conducted rigorously. The results, announced in 2007, were not what Metabolic [3] Pharmaceuticals needed: the primary endpoint was not met. AOD-9604 did not produce statistically significant weight loss compared to placebo in the pivotal trial. Clinical development was terminated.
THE CENTRAL TENSION — READ THIS BEFORE ANYTHING ELSE
AOD-9604's name literally stands for Anti-Obesity Drug 9604. Its clinical development program was specifically, exclusively designed to demonstrate human fat loss. Six trials. 900+ participants. Rigorous methodology. The pivotal trial failed. No regulatory body has ever approved AOD-9604 for any indication. WADA banned it. The FDA in December 2024 recommended against allowing it to be legally compounded. And it is one of the most widely marketed fat loss peptides in the community, sold with claims of lipolysis and body composition improvement at doses (250-500 mcg SubQ daily) that are roughly 20-60x below the oral doses that failed the pivotal trial. The community is using a compound that tried to prove it burns fat in humans and failed to do so, at doses too low to even replicate the trials that failed.
After the obesity program failure, the most scientifically credible AOD-9604 application is cartilage repair and osteoarthritis treatment — an application the community rarely discusses but that has more legitimate scientific traction than the fat loss use case. Animal studies consistently show: AOD-9604 promotes chondrocyte proliferation and matrix synthesis in cartilage tissue; reduces cartilage degradation markers in OA models; has anti-inflammatory effects within joint tissue; and in some models, promotes cartilage repair at injury sites. The route of administration matters here: direct intra-articular injection into the joint space bypasses the systemic bioavailability problem that likely undermined the oral obesity program, potentially delivering active concentrations directly to the target tissue. Metabolic Pharmaceuticals licensed AOD-9604 for this application after abandoning the obesity program. Some clinical interest has been registered; no completed Phase 2 human OA trial with published results existed as of May 2026. Grade C for cartilage repair: consistently positive animal data; mechanistically plausible via local injection; human OA data pending.
The community implication: for users who obtain AOD-9604 for injectable use, the application with better scientific support (cartilage/OA via intra-articular injection) is the one with the most relevant route of administration overlap with community SubQ protocols. SubQ injection produces systemic exposure — it's not the same as intra-articular, but it's closer to local tissue delivery than oral. Whether systemic AOD-9604 at community doses produces sufficient joint/cartilage exposure to have chondroprotective effects is unknown.
AOD-9604: a synthetic 16-amino acid peptide. Sequence: Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe-NH2. Molecular weight approximately 1,818 Da. The peptide corresponds to amino acids 177-191 of human growth hormone (with the N-terminal tyrosine substitution — hence some sources cite it as 176-191 or 177-191 depending on whether the substituted tyrosine is counted as position 176 or as a separate modification). The two cysteine residues at positions 7 and 15 of the sequence form a disulfide bond in the native conformation, contributing to structural stability. The C-terminal amide (-NH2) provides additional stability against carboxypeptidase degradation.
The key structural distinction from full-length hGH: AOD-9604 lacks the receptor-binding domains that allow full GH to activate the GH receptor (GHR). Full hGH binds GHR through its N-terminal helix (amino acids 1-50 primarily) and a second binding site (amino acids 103-126). AOD-9604's C-terminal fragment does not include these binding regions — which is why it consistently fails to activate GHR in binding assays and fails to raise IGF-1 in clinical trials.
AOD-9604 = HGH Fragment 176-191 = Frag 176-191 = AOD9604. All refer to the same compound. The 'Fragment 176-191' and 'Frag 176-191' names are common in community contexts; 'AOD-9604' is the pharmaceutical development designation. When purchasing research-grade product, verify by mass spectrometry (~1,818 Da) — the compound is straightforward to synthesize and generally well-characterized by reputable vendors.
Lyophilized AOD-9604: store at -20°C for long-term; 2-8°C for up to 6 months sealed. Reconstitute with bacteriostatic water. Refrigerate at 2-8°C after reconstitution; use within 30 days. The disulfide bond is the main stability concern — avoid conditions that would reduce it (excessive heat, certain reducing agents). Clear, colorless solution upon reconstitution. HPLC purity 98%+. Mass spectrometry confirming ~1,818 Da is the identity check. Pricing 2026: 5 mg research-grade AOD-9604: $30-70.
AOD-9604's mechanism is characterized more by what it does NOT do than by a fully established positive mechanism. The negatives are well-documented in human trials. The positive lipolytic mechanism is documented in animal models and is pharmacologically plausible. Whether that positive mechanism operates at community doses in humans is the unresolved question.
THE NEGATIVES ARE THE MOST RELIABLY ESTABLISHED FINDINGS
Multiple human clinical trials documented these consistently: NO GH receptor binding — confirmed in receptor binding assays; NO IGF-1 elevation — confirmed across multiple clinical trials at multiple dose levels; NO effect on glucose homeostasis — fasting glucose and insulin sensitivity unchanged; NO effect on thyroid hormone levels; NO tissue growth or anabolism — height, bone density, and lean mass unchanged in trials; NO significant adverse events above placebo rate. These are Grade A findings from human clinical data. They are the most reliable facts in AOD-9604's evidence base.
In animal studies, AOD-9604 produces lipolysis through mechanisms that appear distinct from classical GH receptor signaling. The proposed pathway: AOD-9604 activates beta-3 adrenergic receptor-adjacent signaling in adipose tissue, stimulating lipolysis (triglyceride breakdown to fatty acids) and fat oxidation. Beta-3 adrenergic receptors (β3-AR) are expressed primarily in adipose tissue and are the primary target of many proposed lipolytic compounds. The activation appears to involve the cyclic AMP/PKA pathway downstream of β3-AR, which then activates hormone-sensitive lipase (HSL) to break down stored triglycerides. In obese mouse models and in rat fat pad assays, AOD-9604 consistently stimulated lipolysis at nanomolar to micromolar concentrations. These are well-replicated animal findings. Grade B for animal lipolytic mechanism; Grade D for human lipolytic mechanism (clinical trials did not confirm meaningful lipolysis translation to weight loss).
The gap between 'stimulates lipolysis in rat fat pads' and 'reduces weight in obese humans' is the gap that destroyed AOD-9604's pharmaceutical program. Possible explanations for why the animal mechanism didn't translate: (1) The oral bioavailability of AOD-9604 may be very low, meaning the doses that produced lipolysis in animals weren't achieved in the clinical trial participants despite oral doses of 1 mg/day; (2) The β3-adrenergic receptor density and pharmacology differ between rodents and humans — rodents have much higher β3-AR density in adipose tissue, making them more responsive to β3-AR agonists than humans; (3) The degree of lipolysis produced at safe human doses may be too small to overcome the compensatory mechanisms that regulate body weight in chronically obese humans. None of these explanations invalidates the animal mechanism — they explain why a pharmacologically real mechanism in animals didn't produce a clinically useful signal in humans. The same translation failure has occurred with multiple β3-AR agonists over the past two decades — it is a well-recognized challenge in metabolic pharmacology.
The post-failure pivot: after Metabolic Pharmaceuticals abandoned the obesity program, research interest shifted to AOD-9604's potential for cartilage repair. Animal studies showed AOD-9604 promoted chondrocyte (cartilage cell) proliferation, reduced cartilage degradation in osteoarthritis models, and had anti-inflammatory effects within joints. The mechanistic basis is less characterized than the lipolytic mechanism — potentially involving interactions with proteoglycan synthesis pathways or direct chondroprotective signaling. Local intra-articular injection (directly into the joint) avoids the systemic bioavailability problem that may have undermined the oral obesity program. Grade C: consistent animal model findings; limited human data (some clinical interest has been registered but not published as completed trials as of 2026).
AOD-9604's clinical evidence base is unusual: extensive safety data from multiple trials, and a clear efficacy failure in the pivotal trial. Both deserve equal documentation.
Trial
Year
n
Design
Key Finding
Phase I safety
~1998-2000
Small
Open-label safety
Safe; no GHR binding; no IGF-1 elevation
Phase II dose-finding (multiple)
2001-2004
~200 total
Randomized; several dose levels oral
Modest weight loss signal at 1 mg/day oral; 2.6 kg vs 0.8 kg placebo at 12 weeks (one trial)
Phase IIb OPTIONS Study
2005-2007
536
RDBPC; 24 weeks; primary endpoint: weight loss at 12 weeks
PRIMARY ENDPOINT NOT MET — no statistically significant weight loss vs placebo
The OPTIONS Study was Metabolic Pharmaceuticals' bid to confirm the modest Phase II signal and advance to Phase III and NDA submission. Key design parameters: 536 participants; obese adults (BMI 28-45); randomized, double-blind, placebo-controlled; oral AOD-9604 at multiple doses (0.25 mg, 0.5 mg, 1 mg, 2 mg daily); 24 weeks of treatment; primary endpoint: weight loss at 12 weeks. The trial was powered to detect a clinically meaningful difference. Results (announced 2007): the primary endpoint of statistically significant weight loss at 12 weeks was not met. The development program was terminated. The full results of the OPTIONS trial were not published as a peer-reviewed paper — a common pharmaceutical development outcome when programs are discontinued. The announcement and subsequent communications from Metabolic Pharmaceuticals confirmed the failure.
THE DOSE PROBLEM — WHY COMMUNITY DOSING CANNOT BE EXPECTED TO WORK
The clinical trials used AOD-9604 at 0.25 mg to 2 mg/day orally. Oral peptide bioavailability for AOD-9604 is poorly characterized but likely in the 1-5% range for a 16-amino acid peptide. This means: 1 mg oral dose ≈ approximately 0.01-0.05 mg absorbed systemically. The community uses 0.25-0.5 mg/day by SubQ injection, where bioavailability is much higher (~80-100%). Systemic exposure from 0.5 mg SubQ is therefore roughly 10-50x higher than from 1 mg oral. BUT: even the 1 mg/day oral dose that produced modest effects in smaller Phase II trials was not sufficient to meet the primary endpoint in the larger pivotal trial. The 0.25 mg SubQ dose at the lower community range is likely not superior to the 1 mg oral dose that failed. Community users are not using doses that have shown reliable efficacy in any trial. They are using doses based on peptide convention (similar to other GH fragment protocols) that have no specific validation for this compound.
The positive signal from earlier Phase II trials (approximately 2.6 kg vs 0.8 kg placebo at 12 weeks with 1 mg/day oral) deserves honest framing. It was statistically significant in a small trial. A 1.8 kg difference over 12 weeks is approximately 0.15 kg per week — not clinically meaningful by FDA standards (typically requiring at least 5% body weight reduction). The signal may have reflected natural weight fluctuation variability in a smaller sample, or a genuine but clinically marginal biological effect. Either way, the larger, better-powered OPTIONS trial specifically designed to confirm it did not find it. The Phase II positive signal is not vindicated by the Phase IIb failure; it is superseded by it.
Claim
Evidence
Grade
Key Point
Does NOT bind GH receptor
Multiple binding assays; multiple clinical trials (no GH-like effects)
A
Most reliably established fact about this compound
Does NOT raise IGF-1
Consistent across 6 human trials
A
Directly confirmed in human clinical data
Does NOT affect glucose homeostasis
Consistent across 6 human trials
A
Directly confirmed in human clinical data
Safe in humans (900+ participants)
6 clinical trials; safety profile = placebo
A
Most extensive safety database of any injectable research peptide in this book
Lipolytic in animals (rats, mice)
Multiple independent animal studies; Frank Ng group
B
Well-replicated preclinical finding
Fat loss in humans (Phase II smaller trials)
Modest signal: 2.6 kg vs 0.8 kg, 12 weeks, 1 mg/day oral
C
Statistically significant in small sample; clinically marginal
Fat loss in humans (Phase IIb OPTIONS, n=536)
PRIMARY ENDPOINT NOT MET
A (for NEGATIVE result)
The pivotal trial failed; development terminated 2007
Cartilage repair / chondroprotection
Animal OA models; in vitro human tissue
C
Consistent animal data; human OA trial data pending
Community fat loss at 250-500 mcg SubQ
Community self-reports
E
Doses far below failed trial doses; confounded by diet/exercise; no controlled data
THE FUNDAMENTAL PROTOCOL PROBLEM
Community protocols for AOD-9604 are derived by analogy from growth hormone peptide protocols (CJC-1295, Ipamorelin, etc.) — 250-500 mcg once daily, fasted, SubQ. This protocol was not designed for AOD-9604 specifically; it was adapted by convention. The clinical trials used oral dosing at 0.25-2 mg/day. The community doses (250-500 mcg SubQ = 0.25-0.5 mg SubQ) are within the lower range of the clinical trial doses by absolute mg — BUT the route change from oral to SubQ dramatically changes bioavailability and the doses are being used in a different population (lean athletes vs obese clinical trial participants) for a different purpose (body recomposition in lean individuals vs obesity treatment). None of the clinical trial evidence validates the specific community protocol.
Parameter
Community Protocol
Clinical Trial Reference
Dose
250-500 mcg (0.25-0.5 mg) once daily
0.25-2 mg/day orally (OPTIONS trial); community SubQ is within absolute dose range but different route and population
Route
SubQ injection
Oral (trials); SubQ was not the route studied for fat loss
Timing
Fasted, morning or before bed
No specific timing requirement in trials; fasted state rationale is theoretical
Cycle
4-12 weeks on; 4-8 weeks off
Trials used 12-24 weeks continuous; cycling convention borrowed from GH peptide practice
Stacking
Often combined with CJC-1295 + Ipamorelin or GHRH/GHRP combinations
Not evaluated in combination in any trial
Standard 5 mg vial: add 2 mL bacteriostatic water → 2,500 mcg/mL. 0.1 mL (10 units on a 100-unit insulin syringe) = 250 mcg. 0.2 mL = 500 mcg. Refrigerate; use within 30 days. HPLC purity 98%+; mass spec confirmation at ~1,818 Da for identity verification.
Community practice is to administer AOD-9604 in a fasted state, either first thing in the morning or before sleep. The rationale: insulin suppresses lipolysis; fasted state minimizes insulin levels; therefore AOD-9604's proposed lipolytic effects are theoretically maximized without competing insulin. This logic is mechanistically sound for any lipolytic compound. Whether it matters for AOD-9604 at community doses — given that the compound failed to demonstrate meaningful lipolysis in trials — is a separate question. The fasting protocol does no harm and has theoretical rationale.
AOD-9604 has the most extensive safety database of any research injectable peptide in this book — 6 clinical trials, 900+ participants, with a safety profile indistinguishable from placebo across all trials. This is not a minor finding. It means that at the oral doses tested (0.25-2 mg/day for up to 24 weeks), AOD-9604 produced no adverse effects that were distinguishable from background health events in the placebo group. No significant laboratory abnormalities, no cardiac effects, no hormonal disruption, no tissue growth, no unexpected organ effects. The compound is, by clinical trial evidence, genuinely safe at the doses studied.
The FDA's stated concern when declining to include AOD-9604 on the 503A compounding bulks list in December 2024 included 'potential immunogenicity.' This refers to the theoretical risk that a synthetic peptide could, in some individuals, trigger an immune response — antibody formation against the peptide itself, or in rare cases, cross-reactivity against native growth hormone. The 900-participant trial program did not document immunogenicity events, but these trials were not specifically designed with long-term immunogenicity monitoring. The FDA's concern reflects regulatory caution about synthetic peptides generally, not a documented signal in AOD-9604 specifically. Community users with autoimmune conditions or known peptide hypersensitivity should be aware of this theoretical concern.
WADA S2 — BANNED FOR ALL ATHLETES
AOD-9604 is listed under WADA's S2 category (Peptide Hormones, Growth Factors, and Related Substances) — BANNED at all times, in and out of competition. No TUE pathway. This ban applies despite the absence of confirmed performance enhancement in human trials — WADA's precautionary approach to GH-derived fragments reflects regulatory caution, not confirmed ergogenicity. Athletes in any sport governed by WADA anti-doping rules cannot use AOD-9604 without committing a doping violation. USADA has documented AOD-9604 as an agent that can appear in anti-doping tests. Detection window in urine: metabolites detectable for several days after administration. The WADA ban is one of the most practically important regulatory facts about this compound for the athletic community.
The FDA Pharmacy Compounding Advisory Committee (PCAC) reviewed AOD-9604 on December 4, 2024. The committee recommended that AOD-9604 NOT be included on the 503A Bulks List — the list of substances that licensed US compounding pharmacies can use without individually authorized prescriptions. The stated basis: limited long-term safety data; peptide impurities risk in compounded preparations; potential immunogenicity. This decision means that as of December 2024, licensed 503A compounding pharmacies in the US should not be compounding AOD-9604 for clinical use. Community users who previously obtained AOD-9604 through US compounding pharmacies will need to source from international pharmacies or research chemical vendors going forward — further removing it from any medical oversight context.
The most common community combination: AOD-9604 + CJC-1295 (no-DAC) + Ipamorelin. The theoretical logic: CJC-1295 and Ipamorelin raise GH and downstream IGF-1; AOD-9604 adds supposed additional fat oxidation through the non-GHR mechanism. The combined protocol aims for the anabolic and recovery benefits of elevated GH/IGF-1 plus AOD-9604's proposed lipolytic contribution. The problem with this logic: if you've already elevated GH sufficiently with CJC/Ipa, endogenous GH itself will produce lipolysis through the GH receptor. Adding AOD-9604 on top of elevated GH to get additional GHR-independent lipolysis may be redundant — your own elevated GH is already activating the lipolytic pathways that AOD-9604 supposedly accesses via a different route. The combination is very common; whether AOD-9604 adds meaningful incremental benefit in this context is unknown and mechanistically uncertain.
Some community users run AOD-9604 standalone without GH secretagogues, specifically for the claimed fat loss without the anabolic/recovery effects of a full GH secretagogue stack. This is the application most directly relevant to the clinical trial evidence — and the clinical trial evidence failed to support it.
For users interested in joint health and cartilage support, AOD-9604 has the most legitimate scientific rationale. The animal chondroprotective data is consistent; the local tissue delivery advantage is pharmacologically sound (SubQ injection producing systemic exposure is not as direct as intra-articular, but better than oral). This application is underrepresented in community discussion relative to the fat loss focus. Users with osteoarthritis or significant joint damage may be the most pharmacologically rational AOD-9604 users.
Community reports of AOD-9604 are highly variable. Some users report subjective fat loss, improved body composition over 4-8 week cycles. Others report no perceptible change. The variability is consistent with what you'd expect from: (1) possible sub-threshold dosing; (2) expectation effects; (3) concurrent diet and training changes that produce the actual body composition change; (4) natural weight fluctuation. The absence of a reliable, consistent community consensus signal — even at the anecdote level — is notable for a compound that's been widely used for over a decade.
The clinical trials enrolled obese adults (BMI 28-45) seeking weight loss. The community primarily consists of relatively lean individuals (athletes, bodybuilders, fitness enthusiasts) seeking further fat reduction or body recomposition. This population difference is important: obese individuals have substantially higher absolute fat mass, higher basal lipolysis dysregulation, and more to gain from any lipolytic stimulus. Lean athletes with already-optimized metabolisms may see no signal from a compound that barely moved the needle in obese patients in a controlled trial. The intended therapeutic population and the actual community using it are as different as they could be.
Following the December 2024 FDA PCAC decision against 503A inclusion, US compounding pharmacy access has been significantly restricted. Research chemical vendor access remains but these products are not manufactured under pharmaceutical GMP standards. Standard quality checks: HPLC purity 98%+; mass spectrometry at ~1,818 Da; endotoxin testing <0.1 EU/mg for injectable use. AOD-9604 is a well-characterized peptide and most reputable research vendors produce it reliably.
The honest position on AOD-9604 in 2026: a compound with genuine mechanistic elegance (the concept of isolating GH's fat-burning activity without its side effects is scientifically interesting), an exceptionally clean safety profile confirmed across six human trials, and a failed pivotal trial for its primary intended indication. The community uses it based on a reasonable biological hypothesis that has not translated to clinical evidence. The cartilage application is the most scientifically supported future direction — and the one the community pays the least attention to.
Ng FM, Sun J, Sharma L, Libinaki R, Hong Ming Y, Rashid G. (1990). Molecular dissection of the human growth hormone: enhanced lipolytic activity of a modified C-terminal fragment. Mol Cell Endocrinol. 70(2):137-46. PMID:2196059. [Ng group Monash University; original characterization of the C-terminal GH fragment's lipolytic properties; the foundational paper for AOD-9604's development]
Murphy MG, Bach MA, Plotkin D, et al. (2001) [2]. Oral administration of the growth hormone receptor antagonist pegvisomant or the growth hormone (GH) secretagogue MK-677 or AOD9604 does not alter the serum concentration of insulin-like growth factor-I in man. Growth Horm IGF Res. 11(5):299-304. [Confirms AOD-9604 does not raise IGF-1 in humans; Phase I level evidence]
Metabolic Pharmaceuticals Limited. (2007). OPTIONS Study results announcement. AOD9604 Phase IIb clinical trial: primary endpoint not met. [Primary source for the pivotal trial failure; not published as a peer-reviewed paper; available through company communications and regulatory documents]
Heffernan M, Summers RJ, Thorburn A, et al. (2001) [4]. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology. 142(12):5182-9. PMID:11713211. [Animal lipolysis mechanism; beta-3 adrenergic receptor-adjacent pathway; Monash group]
Cepero-Lopez MC, et al. (Various). AOD-9604 for osteoarthritis and cartilage repair. [Multiple animal studies showing chondroprotective effects; basis for post-obesity program cartilage research pivot]
Cox HD, Hughes CM, Eichner D. (2014) [5]. Detection and in vitro metabolism of AOD9604. Drug Testing and Analysis. 6(7-8):780-5. PMID:24039232. [WADA-relevant; detection methodology for anti-doping testing; confirms detectability and metabolite characterization]
FDA Pharmacy Compounding Advisory Committee (PCAC). December 4, 2024. Meeting on AOD-9604 (free base and acetate). Recommendation: Do not include on 503A Bulks List. [Key regulatory decision; FDA's stated concerns: limited long-term safety data, peptide impurities, potential immunogenicity]
AOD-9604 has the cleanest safety record in this book and the most direct clinical evidence against its primary claimed application. Both of those facts deserve equal weight.
The central tension resolved: AOD-9604 was designed specifically, explicitly, and professionally to produce human fat loss. Metabolic Pharmaceuticals ran six clinical trials involving more than 900 participants to prove it worked. The pivotal trial failed to demonstrate the primary endpoint. The company terminated development. WADA banned it. The FDA in December 2024 declined to allow it to be legally compounded. The community is using it for fat loss — the exact application it failed to demonstrate — at doses below the doses that failed, in a population completely different from the obese patients who were studied, using a route (SubQ injection) that wasn't even tested in the pivotal trials. The community use of AOD-9604 for fat loss is among the most evidence-unsupported applications in this entire book.
This is not to say AOD-9604 is dangerous — it is among the safest injectable peptides in existence by clinical trial evidence. It is to say that 'safe' and 'effective for fat loss' are different claims, and the evidence for the latter is negative at the clinical trial level. Community users may experience subjective effects or attribute fat loss to AOD-9604 that is actually resulting from improved diet, training, or other compounds in the stack. The absence of proven efficacy does not mean the compound does nothing — it means the controlled evidence doesn't support the primary marketing claim.
The most honest application for AOD-9604 in 2026: the cartilage and joint health application, where the animal data is consistent, the route (local or systemic injection) is more appropriate than oral, and the clinical evidence gap is due to incomplete investigation rather than a failed pivotal trial. For users with osteoarthritis or significant joint damage interested in regenerative approaches, AOD-9604 has a more defensible scientific rationale than for fat loss in lean athletes.
AOD-9604 has the cleanest safety record in this book and the most direct clinical evidence against its primary claimed application. Both of those facts deserve equal weight.
The central tension resolved: AOD-9604 was designed specifically, explicitly, and professionally to produce human fat loss. Metabolic Pharmaceuticals ran six clinical trials involving more than 900 participants to prove it worked. The pivotal trial failed to demonstrate the primary endpoint. The company terminated development. WADA banned it. The FDA in December 2024 declined to allow it to be legally compounded. The community is using it for fat loss — the exact application it failed to demonstrate — at doses below the doses that failed, in a population completely different from the obese patients who were studied, using a route (SubQ injection) that wasn't even tested in the pivotal trials. The community use of AOD-9604 for fat loss is among the most evidence-unsupported applications in this entire book.
This is not to say AOD-9604 is dangerous — it is among the safest injectable peptides in existence by clinical trial evidence. It is to say that 'safe' and 'effective for fat loss' are different claims, and the evidence for the latter is negative at the clinical trial level. Community users may experience subjective effects or attribute fat loss to AOD-9604 that is actually resulting from improved diet, training, or other compounds in the stack. The absence of proven efficacy does not mean the compound does nothing — it means the controlled evidence doesn't support the primary marketing claim.
The most honest application for AOD-9604 in 2026: the cartilage and joint health application, where the animal data is consistent, the route (local or systemic injection) is more appropriate than oral, and the clinical evidence gap is due to incomplete investigation rather than a failed pivotal trial. For users with osteoarthritis or significant joint damage interested in regenerative approaches, AOD-9604 has a more defensible scientific rationale than for fat loss in lean athletes.
Compound
Fat Loss Mechanism
Human Evidence
AOD-9604
β3-AR adjacent lipolysis (proposed); no GHR binding
NEGATIVE Phase IIb (n=536); modest Phase II signal not confirmed
S2 BANNED
Retatrutide
GLP-1/GIP/Glucagon triple agonism
28.7% weight loss Phase 3 (TRIUMPH-4, n=536)
Not banned
GW501516 (Cardarine)
PPARδ agonism; fat oxidation; fiber type switch
Phase 1/2 positive; CARCINOGENICITY (GSK terminated 2007)
S4.4 BANNED
CJC-1295 + Ipamorelin
GH elevation → lipolysis via GHR
B — GH elevation confirmed; fat loss via GH elevation expected
S2 BANNED
— End of AOD-9604 —
THE PEPTIDE BIBLE | AOD-9604 (HGH Fragment 176-191) | For Research & Educational Purposes Only
AOD-9604 (Anti-Obesity Drug 9604; HGH Fragment 176-191; Frag 176-191) is a synthetic 16-amino acid peptide corresponding to the C-terminal region (amino acids 176-191) of human growth hormone, with a tyrosine substituted at the N-terminus for stability. MW ~1,818 Da. Disulfide bond between Cys7 and Cys15. Developed by Professor Frank Ng at Monash University; licensed to Metabolic Pharmaceuticals Limited, Australia. CONFIRMED (Grade A, multiple human trials): Does NOT bind GH receptor. Does NOT raise IGF-1. Does NOT affect glucose homeostasis. Does NOT cause tissue growth. Safety profile indistinguishable from placebo across all trials. LIPOLYTIC MECHANISM (Grade B — animal; Grade D — human): stimulates lipolysis in animal adipose tissue via beta-3 adrenergic receptor-adjacent pathway; cyclic AMP/PKA/HSL activation; translates poorly to human fat loss. CLINICAL TRIALS (6 trials, ~900 participants, 1998-2007): Phase I safety: confirmed safe. Phase II dose-finding (multiple): modest signal at 1 mg/day oral — 2.6 kg vs 0.8 kg placebo at 12 weeks (one trial). Phase IIb OPTIONS Study (n=536, 24 weeks, RDBPC): PRIMARY ENDPOINT NOT MET — no statistically significant weight loss at 12 weeks. Development terminated 2007. No regulatory approval from any agency worldwide. CARTILAGE APPLICATION (Grade C): consistent animal OA models; post-obesity program pivot; local injection advantage; no published human OA trial as of May 2026. COMMUNITY PROTOCOL: 250-500 mcg SubQ daily, fasted, 4-12 week cycles. Dose far below clinical trial doses; route not validated in clinical trials for fat loss. WADA: S2 BANNED — at all times, no TUE. FDA: Not approved; PCAC December 2024 recommended AGAINST 503A inclusion (immunogenicity concern, limited long-term safety, peptide impurities). Safety: excellent (900+ participant clinical record). Cancer consideration: low (no IGF-1, no angiogenic mechanism) but standard caution applies. The central tension: the cleanest safety record in this book, used for the exact fat loss application it failed to demonstrate in its pivotal clinical trial, at doses below those that failed, in a population completely different from the studied population.
A Structural Modification of Semax With No Published Studies of Its Own. Being Sold as 'The Most Potent Semax Analog.' Every Claim Belongs to Its Parent Compound.
The Compound That Raises NAD+ By Stopping the Body From Destroying It. NNMT: The Enzyme That Wastes Nicotinamide. Fat Loss Without Food Restriction in Mice. The Neelakantan Group's Research Tool Repurposed as a Longevity Drug. Zero Human Trials. 100 mg/Day Community Dose Extrapolated From Mouse IP Injections. The 1-MNA Question: The Metabolite You're Blocking Has Protective Roles in Liver and Kidney. A 2025 Cell/TPS Review Calls for Clinical Translation. Clinics Already Prescribing It Without FDA Ruling on Safety.
Engineered to Not Be EPO. Proven to Regenerate Nerves in Humans. WADA Banned Anyway. And the Company That Made It No Longer Exists.