> Research Use Only (RUO) Disclaimer: AOD-9604 and HGH Fragment 176-191 are research peptides not approved by the FDA for human use. All information in this article is for educational and scientific reference only. These compounds are intended solely for laboratory and research contexts. This content does not constitute medical advice, diagnosis, or a treatment recommendation. Always consult a qualified healthcare professional before considering any peptide compound.
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# AOD-9604 / HGH Fragment 176-191 Dosage Protocol Guide — Reconstitution, Administration & Research Protocols (2026)
AOD-9604 is one of the most-studied fat-targeted research peptides available. Derived from the C-terminus of human growth hormone (amino acids 176–191), it was engineered by Metabolic Pharmaceuticals to replicate HGH's lipolytic activity without elevating IGF-1, insulin, or glucose — the primary side-effect concerns associated with full-length growth hormone.
This guide covers the complete research dosage protocol: how to reconstitute AOD-9604 and HGH Fragment 176-191, how the two products differ structurally and dosing-wise, standard research dosage ranges, injection technique, timing, cycle guidance, and storage requirements.
For the underlying biology and mechanism of action, see the AOD-9604 research profile and the AOD-9604 vs Fragment 176-191 comparison article. The AOD-9604 peptide profile contains supplier and sourcing information.
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AOD-9604 vs HGH Fragment 176-191: Understanding What You Are Dosing
Before examining specific protocols, it is critical to distinguish between these two closely related compounds — researchers often use the names interchangeably, but they are structurally distinct products with slightly different dosing considerations.
HGH Fragment 176-191 is the unmodified C-terminal fragment of human growth hormone, spanning residues 176 through 191. It retains the native amino acid sequence exactly as it appears in endogenous HGH. The key limitation of the native fragment is its extremely short half-life: approximately 15–20 minutes in plasma due to rapid enzymatic degradation.
AOD-9604 (Anti-Obesity Drug 9604) is a modified version of this fragment developed for pharmaceutical development. The key structural modifications are:
- •A tyrosine residue substitution at the N-terminus (replacing the native phenylalanine), improving receptor binding and stability
- •A disulfide bridge between two cysteine residues, which cyclizes the peptide and dramatically increases resistance to enzymatic breakdown
The result is that AOD-9604 has a meaningfully longer functional half-life, stronger lipolytic potency per unit dose, and the additional distinction of having undergone six formal Phase I/II human clinical trials involving approximately 900 participants — a clinical development pedigree that makes it unusually well-characterized for a research peptide.
In terms of dosing: AOD-9604 is generally effective at a single daily injection, while HGH Fragment 176-191's shorter half-life means researchers typically use a split twice-daily dosing schedule to maintain continuous receptor engagement.
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Reconstitution Protocol
Both AOD-9604 and HGH Fragment 176-191 are supplied as lyophilized (freeze-dried) powder, typically in 2 mg or 5 mg vials. Reconstitution requires bacteriostatic water (BAC water) — standard sterile water is not recommended because it lacks benzyl alcohol preservative and degrades the peptide faster once reconstituted.
Standard Reconstitution: 5 mg Vial
| Bacteriostatic Water Added | Resulting Concentration | Volume per 250 mcg dose | Volume per 500 mcg dose |
|---|---|---|---|
| 1.0 mL | 5,000 mcg/mL | 0.05 mL (5 units on U-100 syringe) | 0.10 mL (10 units) |
| 2.0 mL | 2,500 mcg/mL | 0.10 mL (10 units on U-100 syringe) | 0.20 mL (20 units) |
| 2.5 mL | 2,000 mcg/mL | 0.125 mL (12.5 units on U-100 syringe) | 0.25 mL (25 units) |
Recommended reconstitution for ease of dosing: Add 2.0 mL bacteriostatic water to a 5 mg vial for a concentration of 2,500 mcg/mL (2.5 mg/mL). At this concentration, 10 units on a standard U-100 insulin syringe = 250 mcg.
Step-by-Step Reconstitution
1. Allow the vial to reach room temperature (approximately 15–20 minutes from refrigerator)
2. Clean the rubber stopper with an alcohol swab; allow to dry
3. Draw the desired volume of bacteriostatic water into an insulin syringe
4. Insert the needle at an angle and inject the water down the side of the vial — do not spray directly onto the lyophilized powder cake
5. Do not shake — swirl gently until the powder dissolves completely
6. The solution should be clear and colorless. Any cloudiness, particulates, or color indicates product degradation
7. Label with reconstitution date and store refrigerated (2–8°C)
Shelf life once reconstituted: Up to 30 days refrigerated for bacteriostatic water reconstitution. Protect from light and freeze-thaw cycles.
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AOD-9604 Research Dosage Protocols
Standard Research Dosage Range
Published clinical data and standard research protocols establish the following dosing framework for AOD-9604:
| Protocol Level | Dose | Frequency | Total Daily |
|---|---|---|---|
| Conservative | 250 mcg | Once daily, AM fasted | 250 mcg |
| Standard | 300 mcg | Once daily, AM fasted | 300 mcg |
| Moderate | 500 mcg | Once daily, AM fasted | 500 mcg |
| Split Advanced | 250 mcg | Twice daily (AM + PM fasted) | 500 mcg |
| Advanced Cut | 500 mcg | Twice daily (AM + PM fasted) | 1,000 mcg |
Most commonly referenced research dose: 300–500 mcg once daily in the morning fasted state.
The Phase I/IIa clinical trials conducted by Metabolic Pharmaceuticals (2001–2004) used oral doses of 1–9 mg daily — much higher than the injectable subcutaneous doses used in research protocols, reflecting the dramatically higher bioavailability of subcutaneous injection compared to oral administration. The METAOD005 study (Thompson et al., 2004), a 12-week randomized, double-blind, placebo-controlled trial, demonstrated statistically significant fat loss at 1 mg/day oral dosing, establishing proof-of-concept for dose-dependent lipolytic activity.
Because subcutaneous injection has substantially higher bioavailability than oral delivery, research-context injectable doses typically fall in the 250–500 mcg range — far below the oral clinical doses — while still engaging the same adipose-specific beta-3 adrenergic receptor pathway.
Timing: Why Fasted State Matters
AOD-9604 and Fragment 176-191 both work by stimulating fat mobilization through the beta-3 adrenergic receptor pathway. Insulin is a powerful inhibitor of lipolysis. Dosing in a fasted state (minimum 2–3 hours without food, ideally first thing in the morning before eating) minimizes insulin levels and allows the peptide's lipolytic signal to operate without competing suppression.
Morning fasted administration is considered standard. If a twice-daily protocol is used, the second injection should similarly be administered in a fasted window — at minimum 2 hours after the last meal.
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HGH Fragment 176-191 Research Dosage Protocols
HGH Fragment 176-191's key dosing distinction is its very short plasma half-life (approximately 15–20 minutes). This creates the need for a different dosing strategy compared to AOD-9604.
Standard Research Dosage Range: Fragment 176-191
| Protocol Level | Dose | Frequency | Total Daily |
|---|---|---|---|
| Entry | 250 mcg | Once daily, AM fasted | 250 mcg |
| Standard | 250 mcg | Twice daily (AM + PM fasted) | 500 mcg |
| Moderate | 500 mcg | Twice daily (AM + PM fasted) | 1,000 mcg |
| Advanced | 500 mcg | Three times daily (AM/midday/PM fasted) | 1,500 mcg |
The twice-daily protocol is considered the minimum effective research design for Fragment 176-191 due to its short half-life. A single daily injection provides only a brief receptor engagement window. Splitting the dose into two fasted injections (morning and evening, at least 6 hours apart) maintains more consistent adipose-receptor signaling throughout the day.
AOD-9604 vs Fragment 176-191: Head-to-Head Dosing Comparison
| Parameter | AOD-9604 | HGH Fragment 176-191 |
|---|---|---|
| Structural modification | Tyrosine N-terminus + disulfide bridge | Unmodified native sequence |
| Plasma half-life | Longer (improved by cyclization) | ~15–20 minutes |
| Typical research dose | 250–500 mcg/day | 500–1,000 mcg/day (split) |
| Optimal frequency | Once daily | Twice daily minimum |
| Route | Subcutaneous injection | Subcutaneous injection only |
| Fasted requirement | Yes (strongly recommended) | Yes (essential) |
| Oral bioavailability | Yes (studied in clinical trials) | No (not viable orally) |
| Clinical trial history | 6 Phase I/II trials, ~900 subjects | No human trial data |
| IGF-1 elevation | None confirmed across trials | Not studied in humans |
The practical research implication: AOD-9604 is simpler to dose (once daily, longer window), while Fragment 176-191 requires more frequent dosing to compensate for its rapid clearance. Total daily doses for Fragment 176-191 protocols are therefore typically higher than for AOD-9604.
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Subcutaneous Injection Technique
Both compounds are administered exclusively via subcutaneous (SubQ) injection. Intramuscular injection is not the standard for either peptide. Oral administration is not viable for Fragment 176-191 and is generally not used for AOD-9604 in research contexts despite its clinical trial history using oral doses.
Equipment
- •Syringe: U-100 insulin syringe, 27–31 gauge, 0.5 inch needle
- •Alcohol swabs: For vial stopper and injection site prep
- •Sharps container: For safe disposal
Injection Sites
The lower abdomen is the primary and most recommended injection site for both compounds. The adipose tissue concentration in the abdominal region provides an appropriate SubQ layer and may enhance local delivery dynamics.
- •Abdomen: Inject 2–4 inches to either side of the navel, avoiding the immediate periumbilical area. Pinch a fold of skin and inject at a 45–90 degree angle depending on available subcutaneous tissue depth.
- •Alternative sites (rotation): Upper outer thigh, upper buttock. Rotating sites within the abdomen and to alternates reduces local tissue irritation and lipodystrophy risk.
Step-by-Step Injection
1. Wash hands thoroughly
2. Draw the calculated dose volume from the reconstituted vial
3. Remove any air bubbles from the syringe by flicking and gently depressing the plunger
4. Wipe the injection site with an alcohol swab; allow 10 seconds to dry
5. Pinch the skin to raise a fold of subcutaneous tissue
6. Insert the needle at a 45° angle (or 90° if substantial subcutaneous fat is present)
7. Inject slowly and steadily; do not aspirate for SubQ injections
8. Withdraw the needle at the same angle; apply light pressure with a swab — do not rub
9. Dispose of the syringe and needle in a sharps container
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Research Cycle Length
AOD-9604 and Fragment 176-191 do not suppress the hypothalamic-pituitary-testicular axis (HPTA) and do not require post-cycle therapy (PCT). This is one of their distinguishing properties compared to performance peptides like GHRPs or full-length growth hormone.
Standard research cycle lengths range from 8 to 16 weeks, with 12 weeks representing the most commonly referenced duration in the clinical literature. After this period, a structured break allows assessment of persistent metabolic effects before continuing.
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Storage Instructions
| Condition | Guidance |
|---|---|
| Lyophilized (unopened) | Store refrigerated (2–8°C) up to product expiration date; can withstand brief room temperature shipping |
| Reconstituted with BAC water | Refrigerate at 2–8°C; use within 30 days |
| Freeze-thaw cycles | Avoid completely — degrade peptide integrity |
| Light exposure | Protect from direct light (amber vials preferred, or wrap in foil) |
| Temperature fluctuation | Minimize; do not leave at room temperature longer than necessary for preparation |
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Safety Profile and Research Context
AOD-9604's clinical development program — six Phase I/II trials across approximately 900 participants — established a consistently favorable safety profile. The Thompson et al. (2004) Phase IIa study reported no clinically significant changes in fasting glucose, insulin, HbA1c, IGF-1, cortisol, thyroid hormones, or liver enzymes at doses up to 9 mg/day orally over 12 weeks. The U.S. FDA reviewed the compound's toxicology data and granted it Generally Recognized As Safe (GRAS) status for use as an oral food ingredient — an unusual designation for a synthetic peptide.
The subsequent Phase 2b trial (METAOD006 / OPTIONS) enrolled more than 500 obese adults and failed to meet its primary weight-loss endpoint, which led Metabolic Pharmaceuticals to halt the formal drug development program in 2007. AOD-9604 therefore remains a research peptide rather than an approved pharmaceutical.
HGH Fragment 176-191 has not undergone human clinical trials. Research protocols for the unmodified fragment are extrapolated from AOD-9604 data, adjusted for the different bioavailability and half-life characteristics of the native sequence.
Both compounds appear on the World Anti-Doping Agency (WADA) Prohibited List under "Growth Hormone Releasing Factors" — a relevant consideration for research involving competitive athlete populations.
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Key Peer-Reviewed References
1. Thompson, C.H. et al. (2004). A phase IIa study of the pharmacokinetics, pharmacodynamics and safety of AOD9604 in obese adults. Journal of Clinical Pharmacology, 44(3), 245–256. — Established safety profile and dose-dependent fat loss in 12-week, placebo-controlled trial.
2. Heffernan, M.A. et al. (1999). The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knockout mice. Endocrinology, 140(11), 5
3. Ng, F.M. et al. (2000). Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Hormone Research, 53(6), 274–278. — Confirmed lipolysis mechanism via beta-3 adrenergic receptor and selective fat-targeting without IGF-1 changes.
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Summary: Research Dosage Quick Reference
AOD-9604:
- •Dose: 250–500 mcg/day subcutaneous
- •Frequency: Once daily (AM, fasted)
- •Reconstitution: 2.0 mL BAC water per 5 mg vial → 10 units on U-100 syringe = 250 mcg
HGH Fragment 176-191:
- •Dose: 500–1,000 mcg/day subcutaneous (split)
- •Frequency: Twice daily (AM + PM, both fasted)
- •Reconstitution: Same as AOD-9604; higher total daily volume due to split dosing
Both: SubQ injection, fasted state, refrigerated storage, 8–16 week research cycles, no PCT required.
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This article is for scientific and educational reference only. AOD-9604 and HGH Fragment 176-191 are research peptides not approved for human use. This content does not constitute medical advice. For research purposes only. Not for human use.