AOD-9604: Failed Phase 2b, Dosage & Reconstitution

AOD-9604 at a glance

Bottom line

The confirmatory 24-week Phase 2b (METAOD006) missed its primary endpoint — no statistically significant weight loss versus placebo at 12 or 24 weeks. Obesity development was terminated in February 2007 and no Phase 3 followed.

What it is

Synthetic cyclic 16-mer peptide, sequence YLRIVQCRSVEGSCGF, closed by a disulfide bridge between its two cysteines. It is described equivalently as hGH(177-191) with an added N-terminal tyrosine or as hGH(176-191) with the native phenylalanine replaced by tyrosine; both descriptions give the same molecule. Differs from HGH Fragment 176-191 by one amino acid.

Researched for

Obesity and fat loss (six placebo-controlled human trials in roughly 900 subjects; program terminated 2007); osteoarthritis and cartilage repair (rabbit model only); oral nutraceutical ingredient

Trial-documented dosing

IV 25-400 mcg/kg in early-phase work; oral 0.25-54 mg/day in later trials, with the confirmatory Phase 2b at 0.25/0.5/1 mg/day orally

Community-reported range

250-500 mcg/day subcutaneously (~300 mcg the modal figure) — no published human trial or pharmacokinetic study supports this route or dose

Route reported

Trials: oral and intravenous only. Reported real-world use: subcutaneous injection of reconstituted lyophilized powder; also compounded troches and topicals

Reported frequency

Once daily, commonly described as morning and fasted; some sources split twice daily. Cycles of 8-12 weeks are conventional, not evidence-based

What the trials did show

Tolerability indistinguishable from placebo across roughly 900 subjects in six placebo-controlled trials — no treatment-related serious adverse events, no significant IGF-1 elevation, no adverse glucose-tolerance effect, no detectable anti-drug antibodies

Regulatory status

Not approved by FDA, and not approved as a drug in any major regulated market, in any dosage form, for any route. It is not eligible for lawful compounding under section 503A on FDA's stated position. US policy on peptide compounding has been revised repeatedly and remains contested, so the current position should be checked against FDA's own published guidance. Prohibited in sport at all times under the WADA Prohibited List (Section S2), which names growth hormone fragments including AOD-9604.

Reported ranges from research/community — examples, not recommendations.

What it is / mechanism

Human growth hormone is functionally bipartite. Its growth-promoting activity — receptor dimerization, hepatic IGF-1 generation, and the downstream insulin antagonism that comes with it — is separable from a C-terminal region that drives fat metabolism. AOD-9604 reproduces only the second half of that molecule. It corresponds to hGH residues 177-191 with a tyrosine added at the N-terminus — equivalently described as hGH 176-191 with the native phenylalanine at position 176 replaced by tyrosine, since both descriptions yield the same sequence, YLRIVQCRSVEGSCGF. The molecule is cyclized by an intramolecular disulfide bridge between its two cysteines, which map to hGH Cys182 and Cys189. In preclinical systems it is reported to stimulate lipolysis in white adipocytes and inhibit lipogenesis, raising fat oxidation and energy expenditure without meaningfully engaging the growth-hormone receptor. This is not marketing language: across six human trials AOD-9604 produced no significant rise in serum IGF-1 and no deterioration in glucose tolerance, which is exactly what a lipolytic-domain-only fragment should look like. The domain separation is the genuinely interesting and genuinely validated part of this molecule — and it is worth being precise that what was validated is the absence of hGH's liabilities, not the presence of a clinical effect. The beta-3 adrenergic receptor claim needs correcting, because nearly every vendor page states it backwards. Heffernan and colleagues (Endocrinology, 2001) tested AOD-9604 in beta3-adrenergic-receptor knockout mice. Acute increases in energy expenditure and fat oxidation still occurred in knockout animals — meaning the immediate lipolytic effect does not require beta3-AR. But chronic treatment failed to reproduce the body-weight and lipolysis changes seen in wild-type mice, indicating that the sustained effect appears to depend on an intact beta-3 pathway. Both hGH and AOD-9604 are reported to upregulate beta3-AR expression, which may secondarily sensitize adipose tissue over time. So the accurate statement is: AOD-9604 increases beta-3 receptor expression, and its long-run effect appears to require that pathway, but it is not a beta-3 agonist and does not act directly through that receptor. Downstream signalling — cAMP, protein kinase A, activation of hormone-sensitive lipase — is inferred from cell and rodent work and has never been demonstrated in humans. No specific high-affinity AOD-9604 receptor has ever been identified. At a molecular level, what this peptide binds is not established. A second and much weaker preclinical line concerns cartilage. Kwon and colleagues (Annals of Clinical and Laboratory Science, 2015) injected AOD-9604 intra-articularly into rabbit knees with collagenase-induced osteoarthritis and reported enhanced cartilage regeneration, with better results when combined with hyaluronic acid. This is a single-species animal model with no human counterpart, and it is the entire basis for the osteoarthritis positioning that later rights-holders pursued. It is best read as a hypothesis, not a result. On AOD-9604 versus HGH Fragment 176-191: true hGH Fragment 176-191 begins with phenylalanine (FLRIVQCRSVEGSCGF) because native hGH residue 176 is Phe. AOD-9604 substitutes tyrosine at that position (YLRIVQCRSVEGSCGF) — a difference of a single hydroxyl group, one oxygen atom. The tyrosine was introduced at Monash University so the peptide could be radioiodinated for tracer studies, and is also described as improving stability and handling. Everything else — the disulfide-cyclized core, the proposed mechanism, the dosing conventions, the anti-doping listing — is shared, and the WADA Prohibited List names the two together on one line. Two consequences follow. First, all six human trials were run on AOD-9604; none of that data belongs to native 176-191, and transferring it is not legitimate. Second, gray-market supply routinely conflates the two labels in both directions, so material sold as one frequently contains the other, and identity cannot be verified without third-party analysis.

Researched effects

AOD-9604's most robust human finding is a negative one, and it belongs at the top rather than buried in a limitations paragraph. The confirmatory 24-week Phase 2b (METAOD006, also referred to as OPTIONS) enrolled 534 obese adults with BMI 30-45 and randomized roughly 500 of them in total to oral 0.25, 0.5 or 1 mg/day or to placebo, all on a supervised diet-and-exercise program, powered to detect a 1.8 kg difference. It missed its primary endpoint: no statistically significant separation from placebo at either 12 or 24 weeks. Development for obesity was terminated in February 2007, no Phase 3 was ever run, and the trial's efficacy results were never published in a peer-reviewed journal — safety data from it were carried into the pooled Stier 2013 tolerability analysis, but the efficacy outcome appears in public only through FDA's own regulatory briefing material on the compound. That non-publication of the efficacy result is itself informative, and it is why the failure is far less well known than the earlier positive signal. That earlier signal came from a 12-week oral Phase 2b (METAOD005) in roughly 300 obese patients across five sites, announced by Metabolic Pharmaceuticals in December 2004, comparing placebo against 1, 5, 10, 20 and 30 mg/day. The 1 mg arm lost approximately 2.8 kg versus approximately 0.8 kg on placebo, with small improvements in cholesterol and impaired glucose tolerance. That result carried an obvious warning sign that was widely ignored at the time and is still ignored today: only the lowest dose worked. An inverted dose-response with no signal at 5-30 mg is a well-recognized red flag for a chance finding rather than a pharmacological effect — non-monotonic dose-response curves do occur in genuine pharmacology, so the pattern is a reason for caution rather than proof of nothing, but the confirmatory study, designed specifically to test the signal, did not reproduce it. What the human record does establish is tolerability. Across roughly 900 subjects there were no treatment-related serious adverse events, no treatment-related withdrawals, no significant IGF-1 elevation, no adverse effect on oral-glucose-tolerance-measured carbohydrate metabolism, and no detectable anti-drug antibodies. For a growth-hormone-derived peptide, avoiding all of hGH's characteristic liabilities is a real pharmacological achievement — it is simply an achievement about safety, not about efficacy. Effects reported in current community and wellness-clinic settings — increased fat loss on a calorie deficit, improved recovery, reduced joint discomfort — are uncontrolled anecdote arising from a subcutaneous route that has never been examined in a single published human trial. Two claims warrant rejection outright. There is no evidence for localized or "spot" fat reduction at injection sites; nothing in the trial record or the preclinical work supports regional targeting, and the reported plasma half-life makes a purely local depot effect implausible. And there is no human evidence for joint or cartilage benefit at all — that idea rests entirely on rabbit knees. Even in the trials, the only efficacy outcome measured was scale weight; body composition, visceral fat, and any long-term outcome were never established.

Dosage — reported ranges (overview)

Two entirely separate dosing worlds exist for this peptide, and conflating them is the most common error in AOD-9604 content. The documented clinical dosing is oral and intravenous: 25-400 mcg/kg body weight intravenously in early-phase work, and 0.25-54 mg/day orally in later trials. The confirmatory 24-week Phase 2b used 0.25, 0.5 and 1 mg/day orally. The 2004 efficacy signal came from 1 mg/day oral, and oral doses of 5-30 mg did not perform better. Separately, a self-affirmed GRAS determination announced by the rights-holder set an oral use level of up to 1 mg per person per day for food and supplement use — a company-announced conclusion about oral exposure rather than an FDA affirmation, and one that says nothing about injection. The scale relationship between those trial doses and community practice is routinely misstated, so it is worth setting out precisely. The confirmatory Phase 2b doses of 0.25, 0.5 and 1 mg/day are 250, 500 and 1,000 mcg/day. The subcutaneous range described in community and clinic settings is 250-500 mcg/day. These are the same order of magnitude — in the 0.25 and 0.5 mg arms, the identical mass. Only the exploratory upper oral doses are substantially larger: 5-30 mg/day in the 2004 study, and up to 54 mg/day across the wider trial program, which is roughly 17 to 180 times the modal 300 mcg subcutaneous figure. This matters for interpretation. If the roughly 40% oral bioavailability reported in animal models is anywhere near correct, the oral arms would have delivered systemic exposure broadly comparable to what a 250-500 mcg subcutaneous dose delivers — which makes the failure of the confirmatory trial harder to dismiss as an underdosing or route artifact than it is usually made out to be. The community and wellness-clinic convention, for which no published human data exists, is 250-500 mcg per day subcutaneously, with roughly 300 mcg/day the most commonly cited figure. Some sources describe weight-based dosing around 2 mcg/kg, and some split the daily amount into two injections. Administration is usually described as once daily in the morning in a fasted state; the stated rationale is avoiding insulin's anti-lipolytic effect, which is physiologically plausible in general but has never been demonstrated for this peptide specifically. Cycle lengths are commonly discussed in research and community settings as 8-12 weeks, sometimes extending past 20 weeks. None of these numbers — the dose, the timing, the fasted state, the cycle length — derives from a trial. They are conventions that propagated through forums and clinic protocols, and they are described here as reported practice, not as instruction or recommendation. Two caveats belong on any dosing discussion. First, the reassuring safety record was generated at oral and IV doses over a maximum controlled exposure of 24 weeks; it does not automatically extend to daily subcutaneous injection or to multi-year use. Second, the reported plasma half-life of a few minutes does not obviously support once-daily dosing at all. Dose charts for this compound describe a folk protocol layered on top of a drug program that was discontinued for lack of demonstrated effect.

The full step-by-step protocol examples, titration schedule, and a printable protocol sheet with a dosing and injection log are included in the paid Protocol Playbook for this guide.

Reconstitution — bac-water math

AOD-9604 is supplied as a lyophilized powder, typically in 2 mg, 5 mg or 10 mg vials, and is reconstituted with bacteriostatic water — sterile water containing 0.9% benzyl alcohol as a preservative, which is what permits repeated withdrawals from the same vial over subsequent days. The volume of bacteriostatic water added does not change how much peptide is in the vial; it only sets the concentration, and therefore how many syringe units correspond to a given microgram dose. Larger volumes make small doses easier to measure accurately and are generally preferred when the intended dose sits at the low end; smaller volumes concentrate the product and reduce injection volume. The table below is arithmetic, not advice, and the dose columns reflect community-reported subcutaneous figures for which no published human data exists. Units refer to a standard U-100 insulin syringe, on which 100 units equals 1.0 mL, so 1 unit equals 0.01 mL. Each row uses a volume that puts both dose columns on whole syringe units, since half-unit gradations cannot be measured reliably on a U-100 barrel. Reconstitution is commonly described as adding the water slowly down the inside wall of the vial rather than jetting it onto the powder cake, then swirling the vial or allowing the cake to dissolve on its own rather than shaking it — this is a disulfide-cyclized peptide, and mechanical shear and foaming are the practical enemies of peptide integrity.

This is concentration math, not a dose recommendation.

Injection / administration basics

Subcutaneous administration is what the current market does; it is emphatically not what the trials did, and none of the human safety or efficacy data applies to it. Reported practice, described here for completeness rather than as guidance: the abdomen is the usual site, roughly two inches away from the navel, with sites rotated so that the same spot is not used on consecutive days. A short insulin needle — commonly 29-31 gauge, 5/16 to 1/2 inch — is described, with the skin lifted into a fold to raise subcutaneous tissue away from muscle and the needle inserted at 45 to 90 degrees depending on how much subcutaneous tissue is present. The vial stopper and the injection site are described as wiped with alcohol and allowed to dry before contact. Syringes are described as single-use, with used sharps placed in a dedicated sharps container. Product quality deserves its own paragraph, because it is the concrete regulatory finding on this compound. In its review of AOD-9604 as a proposed compounding bulk substance, FDA flagged immunogenicity risk arising from impurities and aggregates in inadequately characterized bulk material, alongside inadequate physicochemical characterization generally. That is a hazard created by the quality of the manufactured substance rather than by the molecule itself, and it is the risk profile that attaches to unregulated research-use-only vials from unverified supply chains. Aggregates are among the best-documented drivers of unwanted immune responses to therapeutic proteins in general. In practical terms, this is a statement about handling and diluent quality in preparing any injectable peptide solution: a sterile, appropriately preserved diluent such as USP-grade bacteriostatic water rather than improvised liquid; gentle reconstitution rather than shaking a vial into foam; a stopper kept clean; and any cloudy, discolored or particulate-containing solution treated as unusable. Medibact sells bacteriostatic water and digital guides and does not sell peptides — and no diluent, however well specified, makes an unapproved peptide safe or effective. It is also why third-party identity and purity testing matters more for this compound than for most: material sold as AOD-9604 and material sold as HGH Fragment 176-191 are frequently the same product under two labels, and neither claim can be verified from a vial label.

Half-life & frequency rationale

Short — and shorter than the dosing conventions imply. Rodent intravenous studies report a serum half-life on the order of 3-4 minutes. Oral administration in animals showed absorption with plasma levels peaking around 60 minutes, and oral bioavailability has been reported at roughly 40% in animal models. That bioavailability figure deserves skepticism: 40% is unusually high for a 16-residue peptide crossing the gut, it was never firmly established, and it sits oddly against the fact that the oral trials failed. Critically, no published human pharmacokinetic study for AOD-9604 by any route — oral, intravenous, subcutaneous or topical — could be located in the peer-reviewed literature. FDA's review of the compound made a narrower and more specific point: it noted the absence of published human exposure data for the proposed subcutaneous and topical routes. This leaves an open question that should not be papered over. A peptide with a plasma half-life measured in minutes is cleared long before the next day's dose. Once-daily subcutaneous dosing can only be rationalized if the biological effect substantially outlasts plasma exposure — for instance through sustained changes in adipocyte gene expression such as the beta-3 receptor upregulation seen in rodents, or through a slow-release depot effect from the subcutaneous injection site. Both are plausible mechanisms; neither has been demonstrated for AOD-9604 in humans. Community claims of a multi-hour half-life, or of a duration of action that justifies once-daily injection, are not supported by any published human data. A dosing schedule for this peptide describes a convention, not a pharmacokinetically derived regimen.

Stacking — overview

No stack involving AOD-9604 has been studied in humans. Every combination described below is a convention drawn from research and community settings, and combining an unapproved peptide with anything else compounds the unknowns rather than averaging them. That caveat is not boilerplate here: the compound's confirmatory efficacy trial failed on its own, so any stack rationale is built on a foundation that did not hold. The mechanistic logic that gets cited is real, though. Because AOD-9604 does not meaningfully raise IGF-1 and does not affect glucose tolerance, it is discussed as non-overlapping with the GH-secretagogue family — CJC-1295, ipamorelin, sermorelin, GHRP-2 — which work by raising endogenous GH and therefore IGF-1. Whether adding a fragment of GH's lipolytic domain to a protocol that is already elevating full-length GH adds anything is entirely unestablished, and arguably the secretagogue is already delivering the lipolytic domain in its native context. The more coherent pairings discussed are with metabolic agents acting through unrelated pathways, or as a low-stakes adjunct alongside an incretin agent doing the actual work. Worth naming explicitly as comparisons rather than combinations, with regulatory status stated accurately for each. Tesamorelin is a GHRH analog with FDA approval for reduction of excess visceral abdominal fat in HIV-associated lipodystrophy. Semaglutide and tirzepatide are FDA-approved incretin agents that passed large randomized weight-loss trials of exactly the kind AOD-9604's confirmatory Phase 2b failed. Retatrutide belongs in the same mechanistic conversation but not the same regulatory one: it is an investigational triple agonist that has not been approved as a drug in any major regulated market, and its development status is best checked against the sponsor's own disclosures. If the goal being pursued is fat loss with completed trial evidence behind it, the approved incretins and tesamorelin are the honest comparators, and that comparison belongs in plain sight rather than buried.

For how combinations are grouped by research context, the named blends, and why a pre-mixed blend vial cannot be calculated from its total milligrams, see the peptide stacks guide.

Storage & handling

• Lyophilized (unreconstituted) vials are commonly described as stored refrigerated at 2-8 C and protected from light; the dry powder is the stable form and is generally reported to tolerate short periods of ambient-temperature shipping without meaningful degradation.
• Once reconstituted with bacteriostatic water, vials are reported as kept at 2-8 C, protected from light, and not frozen. Freeze-thaw cycling is a recognized driver of peptide aggregation, and aggregates are the specific concern FDA raised about inadequately characterized AOD-9604 material.
• Bacteriostatic water for injection carries a 28-day in-use period after first puncture under USP and manufacturer labeling, and that 28-day window is the limiting factor commonly cited for a reconstituted multi-dose vial. Longer figures such as 30 or 45 days circulate in community sources; those exceed the labeled in-use period for the diluent and are not supported by the product labeling.
• Reconstitution is commonly described as gentle: the diluent is added down the inside wall of the vial rather than directly onto the powder cake, and the vial is then swirled or left to dissolve rather than shaken. Foaming is treated as a sign of mechanical stress on a disulfide-cyclized peptide.
• Solutions that are cloudy, discolored or contain visible particulate are described as unusable. Common practice reported in research settings is to label the vial with the reconstitution date and the resulting concentration in mcg/mL, since it is the concentration — not the vial size — that the syringe arithmetic depends on.

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