How to Reconstitute AOD-9604: Dosing Math (mg, mL, IU, and Units)

What Is AOD-9604 and Why Does the Dosing Math Matter?

AOD-9604 is a synthetic peptide fragment (residues 177 to 191) of human growth hormone (hGH), modified with a tyrosine group at the N-terminus. Unlike full-sequence hGH, it does not raise IGF-1 or affect blood glucose at studied doses, making it a distinct compound with its own pharmacokinetic profile. Because it arrives as a dry powder, the concentration you create during reconstitution directly determines the volume you inject. Get the math wrong and you administer half your dose or four times your dose from the same vial.

AOD-9604's lipolytic mechanism was characterized in animal models at AMRAD Corporation, with the peptide demonstrating stimulation of lipolysis and inhibition of lipogenesis in adipocytes without the diabetogenic effects of full hGH. [1] That receptor selectivity is pharmacologically meaningful, but it does not change the compounding arithmetic: every milligram of lyophilized peptide must be dissolved in a precise volume of diluent before you can draw an accurate dose.

Why Bacteriostatic Water and Not Plain Sterile Water?

Bacteriostatic water for injection (BWI) contains 0.9% benzyl alcohol as a preservative. That preservative inhibits microbial growth across multiple draw events from the same vial, which is the scenario that applies to almost every peptide protocol where you inject once daily for weeks. Sterile water for injection (SWFI) contains no preservative and, per USP 797 standards for compounded sterile preparations, should be used as a single-dose diluent only. [2] Using SWFI in a multi-dose vial creates contamination risk after the first puncture. Use BWI for AOD-9604 unless your compounder or prescribing physician specifies otherwise.

The Stability Window After Reconstitution

Lyophilized peptides are stable at room temperature for shipping, but reconstituted solutions degrade faster. Benzyl alcohol in BWI slows microbial growth; it does not arrest chemical degradation of the peptide backbone. Refrigerate reconstituted AOD-9604 at 2 to 8 °C and discard after 28 days. Some stability data from compounding pharmacies suggest potency loss begins measurably beyond 30 days at refrigerator temperature, consistent with general peptide stability findings reviewed in a 2018 pharmaceutical analysis of GH-fragment peptides. [3] Keep the vial away from light and never freeze a reconstituted solution, as ice crystal formation denatures the peptide structure.

Step-by-Step Reconstitution Protocol

The sequence below follows aseptic technique consistent with USP 797 guidelines for compounded sterile preparations. [2] Each step has a specific rationale.

Step 1: Gather Your Supplies

You need: the AOD-9604 lyophilized vial, a vial of bacteriostatic water for injection, two alcohol swabs (70% isopropyl), a 1 mL or 3 mL syringe with a 23 to 25 gauge draw needle, and a 1 mL U-100 insulin syringe for dosing. Wash hands thoroughly with soap for at least 20 seconds before touching any sterile surface.

Step 2: Swab Both Vial Tops

Wipe the rubber septum of both the peptide vial and the BWI vial with separate alcohol swabs. Allow each to air-dry for 15 to 20 seconds. Do not blow on the surface or fan it dry. A wet septum can push alcohol into the vial on needle insertion.

Step 3: Draw the Diluent

Using the draw syringe, pull back the plunger to the volume of BWI you intend to add (see the concentration table below). Insert the needle into the BWI vial, invert, and draw the precise volume. Remove the needle.

Step 4: Add BWI to the Peptide Vial Slowly

Insert the draw needle through the septum of the AOD-9604 vial. Angle the needle so the stream of BWI runs down the glass wall rather than directly onto the lyophilized cake. Direct impingement can shear the peptide. Push the plunger slowly. This slow-wall technique is standard practice in clinical reconstitution of fragile biologics. [4]

Step 5: Dissolve Without Vortexing

Once BWI is fully added, gently roll the vial between your palms for 15 to 30 seconds. Do not shake or vortex. Vigorous mechanical agitation causes peptide aggregation and foaming. The powder should dissolve to a clear, colorless solution. Discard the vial if the solution appears cloudy, particulate, or discolored.

Step 6: Label and Refrigerate

Write the reconstitution date on the vial. Refrigerate immediately at 2 to 8 °C. Let the vial reach room temperature for 5 to 10 minutes before each subsequent injection to reduce injection-site discomfort.

The Core Concentration Formula

The single equation you need is:

Concentration (mcg/mL) = Total peptide (mcg) ÷ Volume of diluent added (mL)

Everything else, including what to draw into the syringe, flows from this ratio.

Worked Example: 2 mg Vial With 2 mL BWI

• Total peptide: 2 mg = 2,000 mcg
• Diluent added: 2 mL
• Concentration: 2,000 mcg ÷ 2 mL = 1,000 mcg/mL

A prescribed dose of 300 mcg requires:

300 mcg ÷ 1,000 mcg/mL = 0.30 mL

On a U-100 insulin syringe (100 units per mL), 0.30 mL corresponds to the 30-unit mark.

Worked Example: 5 mg Vial With 2 mL BWI

• Total peptide: 5 mg = 5,000 mcg
• Diluent added: 2 mL
• Concentration: 5,000 mcg ÷ 2 mL = 2,500 mcg/mL

A prescribed dose of 500 mcg requires:

500 mcg ÷ 2,500 mcg/mL = 0.20 mL = 20 units on a U-100 syringe

Worked Example: 2 mg Vial With 1 mL BWI (Higher Concentration)

• Total peptide: 2,000 mcg
• Diluent: 1 mL
• Concentration: 2,000 mcg/mL

A 300 mcg dose requires 0.15 mL = 15 units. Smaller injection volume, same dose. Some patients prefer this for abdominal subcutaneous comfort.

Full Dosing Reference Table

| Vial Size | BWI Added | Concentration | 250 mcg dose | 300 mcg dose | 500 mcg dose | |-----------|-----------|---------------|-------------|-------------|-------------| | 2 mg | 1 mL | 2,000 mcg/mL | 0.125 mL / 12.5 units | 0.15 mL / 15 units | 0.25 mL / 25 units | | 2 mg | 2 mL | 1,000 mcg/mL | 0.25 mL / 25 units | 0.30 mL / 30 units | 0.50 mL / 50 units | | 5 mg | 2 mL | 2,500 mcg/mL | 0.10 mL / 10 units | 0.12 mL / 12 units | 0.20 mL / 20 units | | 5 mg | 5 mL | 1,000 mcg/mL | 0.25 mL / 25 units | 0.30 mL / 30 units | 0.50 mL / 50 units |

All "units" values assume a standard U-100 insulin syringe (1 mL = 100 units).

Understanding the IU vs. Mcg Distinction

This is where confusion frequently causes dosing errors. IU (International Units) is a biological activity measure used for hormones like human chorionic gonadotropin (hCG), follicle-stimulating hormone (FSH), and insulin. It is assigned by bioassay, not by mass. AOD-9604 has no established IU bioassay standard. It is dosed entirely by mass, in micrograms (mcg). [5]

Why Some Peptide Forums Use "IU" for AOD-9604

People refer to the syringe markings, not a true IU value. Because insulin syringes are printed in U-100 units, some communities shorthand "30 units on the syringe" as "30 IU." That is technically incorrect but pragmatically describes the syringe mark. When a physician prescribes AOD-9604, the dose will always be in mcg. Convert that mcg value to a syringe volume using the table above, then read the syringe mark.

Converting Between mg and mcg

1 mg = 1,000 mcg. If your prescription reads 0.5 mg, that equals 500 mcg. Use the 500 mcg column in the table above.

Choosing and Using the Right Insulin Syringe

The HealthRX Peptide Syringe Selection Framework rates three variables for subcutaneous peptide dosing: needle gauge, barrel volume, and graduation increments.

Needle gauge. For subcutaneous injections, 29 to 31 gauge needles minimize tissue trauma and bleeding. A 2019 clinical review of subcutaneous injection techniques published in the journal Diabetes Technology and Therapeutics confirmed that 32-gauge needles of 4 mm length produce equivalent insulin bioavailability with lower patient-reported pain scores compared with 29-gauge 8 mm needles. [6] The same principle applies to peptide injections: go fine gauge, short needle.

Barrel volume. A 1 mL barrel is standard. Avoid 0.5 mL insulin syringes for AOD-9604 unless your dose is 0.25 mL or below. Half-mL barrels have graduation marks every 0.005 mL (0.5 units), which is more granular but limits total draw volume.

Graduation increments. U-100 syringes are marked in 1-unit (0.01 mL) increments. For a 300 mcg dose at 1,000 mcg/mL concentration, you draw to the 30-unit mark. Confirm the syringe prints "U-100" on the barrel. U-40 syringes (less common) print 40 units per mL. Confusing U-40 with U-100 produces a 2.5-fold dosing error.

How to Draw the Dose

Swab the reconstituted vial septum. Pull back the syringe plunger to the target volume mark. Insert the needle into the vial, invert, and push the air bubble in. Draw slowly to the target mark. Tap the barrel to float any air bubbles to the top, then push them out. Confirm the volume is at the correct mark before injecting.

Injection Technique for Subcutaneous Administration

Pinch a 1 to 2 inch fold of skin at the injection site. Insert the needle at 45 to 90 degrees depending on body composition (45 degrees for leaner individuals to avoid intramuscular injection, 90 degrees for those with more subcutaneous fat). Inject slowly over 5 to 10 seconds. Release the skin fold before withdrawing the needle. Apply gentle pressure with a clean swab. Rotate sites systematically to reduce lipohypertrophy risk. [7]

Dosing Context: What the Clinical Literature Shows

AOD-9604 reached Phase IIb human trials for obesity through AMRAD/Metabolic Pharmaceuticals. A randomized, double-blind, placebo-controlled study by Heffernan et al. Tested oral AOD-9604 at doses from 1 mg to 30 mg per day for 12 weeks in 300 overweight adults. The 1 mg oral dose group showed statistically significant weight reduction compared with placebo (P<0.05), while higher doses did not outperform placebo, suggesting a non-linear dose-response curve. [1] Subcutaneous formulations were studied at lower mcg-range doses due to the bioavailability advantage of the parenteral route compared with oral delivery.

A separate pharmacokinetic analysis found that subcutaneous AOD-9604 produced peak plasma concentrations within 15 minutes of injection, with a half-life of approximately 30 minutes in healthy volunteers. [8] That short half-life supports once-daily morning dosing to align peak concentration with the natural diurnal lipolysis window, a rationale consistent with guidance from endocrinologists specializing in GH secretagogue protocols. [9]

The Endocrine Society's 2019 clinical practice guideline on growth hormone deficiency does not include AOD-9604 as a recognized therapeutic, since the compound is not FDA-approved. [10] Compounded AOD-9604 for subcutaneous injection exists in a regulatory category distinct from FDA-approved medications, and patients should obtain it only through a licensed compounding pharmacy operating under a valid prescription.

Common Reconstitution Errors and How to Avoid Them

Error 1: Adding Too Much Diluent

Adding 5 mL to a 2 mg vial produces a 400 mcg/mL concentration. A 300 mcg dose then requires 0.75 mL per injection. That is a large subcutaneous volume and may cause local discomfort or suboptimal absorption. Keep concentrations at 1,000 to 2,500 mcg/mL to keep injection volumes below 0.5 mL.

Error 2: Confusing Vial Label Units

Some compounding pharmacy labels read "2 mg" and some read "2,000 mcg." These are identical. If a label reads "2,000 mcg per vial," the total peptide content is 2 mg. Apply the same formula.

Error 3: Not Accounting for Dead Volume

Every syringe retains a small amount of fluid in the hub and needle (typically 0.05 to 0.08 mL dead volume). For most AOD-9604 doses this is clinically insignificant, but if you are near the end of a vial and drawing small volumes, the dead volume can represent a meaningful fraction of your total dose. Use the same syringe type consistently so dead volume is constant and predictable.

Error 4: Storing at Room Temperature After Reconstitution

Lyophilized peptide is stable at room temperature during shipping. Reconstituted solution is not. Benzyl alcohol inhibits microbes; it does not prevent peptide hydrolysis at warmer temperatures. Refrigerate at 2 to 8 °C and never leave the vial on a counter between doses.

Error 5: Re-freezing a Reconstituted Vial

Freezing reconstituted peptide solutions causes ice crystal formation that physically damages the peptide's secondary structure. Discard if accidentally frozen. [3]

Practical Checklist Before Every Injection

• Vial label confirmed (peptide name, concentration, expiry/beyond-use date)
• BWI used as diluent (not plain sterile water)
• Concentration calculated and written on vial
• Correct syringe type confirmed (U-100 vs. U-40 printed on barrel)
• Target volume calculated (dose mcg ÷ concentration mcg/mL)
• Syringe drawn to correct mark, air bubbles removed
• Injection site rotated from previous site
• Vial returned to refrigerator immediately after use