How to reconstitute AOD-9604

What reconstitution means for AOD-9604

Learning how to use AOD-9604 in a lab starts with dissolving the solid in a measured volume, so any volume drawn later holds a known amount. AOD-9604 has no USP or National Formulary monograph and is not part of any FDA-approved product, so no label sets a diluent, a volume or a use-by time.¹ The steps below are general lab handling around the few published AOD-9604 figures, not directions for use in people.

What is in the vial

The vial holds 2 mg of AOD-9604 as a white lyophilized (freeze-dried) solid, with no diluent included.³ Three details matter before any math:

• Salt form. The listing does not say whether the solid is the free base or the acetate salt. FDA gives a molar mass of 1,815.09 g/mol for the free base and 1,875.1 g/mol for the acetate.¹ Weighed as acetate, 2 mg would hold about 1.94 mg of the peptide itself (2 × 1,815.1 ÷ 1,875.1).
• Peptide content. Purity is not content: a powder more than 95% pure by HPLC may be only 70 to 90% peptide by weight, the rest being counter-ions such as acetate and residual water, and a peptide maker says content must be counted when setting a concentration.¹¹
• Testing. FDA found that the certificates of analysis submitted to it, and public sources, lacked specific tests for impurities, aggregates and microbes for AOD-9604.¹ Certificate information for this store is on the lab results page; check which tests a lot's certificate covers before relying on the labeled amount.

The vial listing and its supplies are on the AOD-9604 for sale page.

Why handling matters

FDA is concerned that AOD-9604 may trigger immune reactions, because the peptide can aggregate and carry peptide-related impurities.¹ It notes that pH, heat, concentration, impurities and added ingredients can drive aggregation and degradation, and that the disulfide bridge holding the peptide's loop can break down.¹

Its sequence (YLRIVQCRSVEGSCGF) contains cysteine, glutamine, arginine and glutamic acid.¹⁵ Peptide makers link the first two to limited shelf life, cysteine to oxidation, and the last two to pulling moisture from the air, so they advise warming a cold vial to room temperature before opening it.¹⁰¹¹¹²

Supplies

The supplies listed with this vial are bacteriostatic water, a 3 mL Luer-Lok syringe, an 18G 1-inch needle, insulin syringes and alcohol swabs. Technique common to all freeze-dried vials is covered in How to reconstitute a peptide vial.

Lab steps

1. Check the paperwork. Match the lot number on the vial to its certificate and note which tests it reports.
2. Choose the concentration. Decide the mg per mL the work needs and calculate the diluent volume (math below), staying at or below the 2 mg per mL water solubility FDA cites for the free base.¹
3. Work clean. Use a new sterile syringe and needle, and disinfect the vial stopper with alcohol before each needle entry.¹⁶
4. Add the diluent. Push the plunger slowly so the liquid runs down the inside wall of the vial, not onto the solid. FDA-approved instructions for another freeze-dried peptide, tesamorelin, give this step to avoid foaming.¹³
5. Dissolve gently. Swirl or roll the vial until no solid remains, and do not shake it; both tesamorelin labels give the same instruction.¹³¹⁴ Some peptides take hours to dissolve, and a peptide maker warns against warming the sample too much.¹⁰
6. Inspect. Record any cloudiness or particles: the tesamorelin labels allow only a clear solution,¹³¹⁴ and aggregation is one of the changes FDA describes for this peptide.¹
7. Label and store. Write the compound, concentration, diluent and date on the vial, then return it to cold storage as described below.

Concentration math

The basic formula:

concentration (mg per mL) = mg in the vial ÷ mL of diluent

For cell or tissue work, a molar concentration is often more useful. PubChem gives a molar mass of 1815.1 g/mol for the free base,⁷ so 2 mg is about 1.10 micromoles (0.002 g ÷ 1815.1 g/mol).

Less than 1 mL would take a 2 mg vial past the 2 mg per mL solubility figure.¹ If the solid is the acetate salt, at 1,875.1 g/mol, every molar value is about 3% lower: 1,067 µM at 1 mL.¹ The table assumes 2 mg of peptide, so correct it when a certificate reports a lower peptide content.

To dilute a stock, use C1 × V1 = C2 × V2. For 1 mL of a 100 µM working solution from the 551 µM stock, take 0.18 mL of stock (100 × 1 ÷ 551) and add 0.82 mL of diluent. The reconstitution calculator and the peptide calculator run these numbers for any vial. All of this is lab arithmetic, not an amount for a person.

Storage before and after mixing

Before mixing. Published figures come from suppliers and differ:

• This vial's supplier gives 36 months at -20 °C and 30 days at 2 to 8 °C, and does not say whether the 30-day figure covers the dry solid or the mixed solution.³
• One safety data sheet cited by FDA allows 3 years at -18 °C, 1 year at 0 to 7 °C and half a year at 7 to 30 °C, in closed containers.¹
• For the acetate salt, supplier documents cited by FDA recommend -20 °C, where it is reported stable for more than four years, with 2 to 8 °C only for storage of less than six months.¹

After mixing. No published stability study of reconstituted AOD-9604 was found, so there is no tested use-by time. The only data in solution come from blood and urine samples: a half-life of about 4 minutes in rat plasma, with breakdown from the peptide's starting end,⁸ one breakdown fragment, CRSVEGSCG, that is more stable in serum than the parent peptide,⁹ and extensive degradation in serum and plasma after one week at 4 °C or 22 °C, against at least two months of stability at -20 °C.⁴ Blood is not a vial of peptide in water, so these figures set no shelf life.

Peptide makers advise against storing peptides in solution; when that cannot be avoided, they suggest single-use aliquots kept frozen at -20 °C and no repeated freeze-thaw cycles.¹⁰¹² In approved tesamorelin, the sterile-water version is used at once and the bacteriostatic-water version is discarded 7 days after mixing, and the newer label notes that the two versions differ in reconstitution and storage and are not substitutable.¹³¹⁴ See How to store peptides for general practice.

Related pages

Back to What is AOD-9604?. Study doses are in AOD-9604 dosage, recorded adverse events in AOD-9604 side effects, and reported outcomes in AOD-9604 benefits and uses. Related fragment: What is HGH Fragment 176-191?.