Tesamorelin 2 mg Reconstitution — Dose and Volume Table

Published 2026-07-31 · Lyophile Editorial

Bacteriostatic Water for a 2 mg Tesamorelin Vial — Reconstitution Calculator

Add 1 mL, 2 mL, or 3 mL of bacteriostatic water to a 2 mg tesamorelin vial. Each option yields a different concentration and mcg-per-unit value on a U-100 insulin syringe:

• 1 mL → 2000 mcg/mL → 20 mcg per unit
• 2 mL → 1000 mcg/mL → 10 mcg per unit
• 3 mL → 666.7 mcg/mL → 6.67 mcg per unit

Bacteriostatic water is 0.9% benzyl alcohol in sterile water, preserved per USP <51> antimicrobial effectiveness testing.

Quick Calculator

Enter your target dose and diluent volume:

| Diluent Volume | Concentration | mcg per U-100 unit | 100 mcg dose | 250 mcg dose | 500 mcg dose | |---|---|---|---|---|---| | 1 mL | 2000 mcg/mL | 20 mcg | 5 units | 12.5 units | 25 units | | 2 mL | 1000 mcg/mL | 10 mcg | 10 units | 25 units | 50 units | | 3 mL | 666.7 mcg/mL | 6.67 mcg | 15 units | 37.5 units | 75 units |

Reading the table: find your target dose, read across to your diluent volume. The units column is what you draw into a U-100 insulin syringe — 1 unit = 0.01 mL.

Reconstitution Math — Step by Step

The core formula: peptide mass ÷ total liquid volume = concentration. A 2 mg vial contains 2000 micrograms of lyophilized peptide. The diluent volume you add becomes the denominator.

Example with 2 mL diluent:

• 2000 mcg ÷ 2 mL = 1000 mcg/mL
• U-100 syringe: 100 units per mL → each unit = 10 mcg
• 100 mcg dose = 10 units
• 250 mcg dose = 25 units

Example with 1 mL diluent:

• 2000 mcg ÷ 1 mL = 2000 mcg/mL
• Each unit = 20 mcg
• 100 mcg dose = 5 units
• 250 mcg dose = 12.5 units

Example with 3 mL diluent:

• 2000 mcg ÷ 3 mL = 666.7 mcg/mL
• Each unit = 6.67 mcg
• 100 mcg dose = 15 units
• 250 mcg dose = 37.5 units

The math is identical whether you express it in micrograms or international units — IU is just a volume label on the syringe barrel, not a separate unit of peptide mass.

Tradeoffs: 1 mL vs 2 mL vs 3 mL Diluent

1 mL — smallest injection volume, least forgiving math. A 250 mcg dose is 12.5 units, which splits a half-unit mark — many insulin syringes lack these. You'll estimate between the 12 and 13 unit lines. Upside: tiny subQ injection volume.

2 mL — most practical middle ground. Ten mcg per unit means every 10 mcg is exactly one unit. A 250 mcg dose lands on 25 units — a clean, readable mark on any U-100 syringe. This is the configuration most peptide calculators default to.

3 mL — maximum accuracy for small doses, larger injection volume. At 100 mcg, the 15-unit draw is easy to read. But a 500 mcg dose becomes 75 units — nearly the full syringe. The higher dilution also means more benzyl alcohol per injection, which can sting slightly more.

Practical note: a 2 mg vial is small. Adding 3 mL to a vial that holds roughly 3 mL total leaves almost no headspace. Inject diluent slowly against the vial wall, then swirl gently. Forced agitation of a nearly full vial can cause foaming and peptide denaturation at the air-liquid interface.

How to Reconstitute a 2 mg Tesamorelin Vial

Draw your chosen volume of bacteriostatic water, inject it slowly down the vial wall, and swirl gently until dissolved. Do not shake — vortexing can cause protein aggregation. Tesamorelin is a synthetic peptide and more robust than larger proteins, but mechanical stress from shaking still risks damage.

Steps:

1. Wipe the vial stopper with an alcohol swab and let it dry for 30 seconds
2. Draw your diluent volume (1, 2, or 3 mL) into a sterile syringe
3. Insert the needle through the stopper at a slight angle
4. Inject the diluent slowly against the inner glass wall — not directly onto the lyophilized cake
5. Remove the syringe and gently swirl the vial for 30–60 seconds
6. Let it sit for 5 minutes; the solution should be clear and colorless
7. Store per the peptide's stability profile — typically refrigerated at 2–8°C

Common failure mode: injecting diluent directly onto the peptide cake creates a localized high-concentration zone that can cause precipitation. If you see white particles after reconstitution, the peptide may have crashed out. Gentle warming to room temperature and re-swirling sometimes rescues it, but a precipitated peptide is often a lost vial.

Syringe Selection for Tesamorelin 2 mg

Use a U-100 insulin syringe with a fixed needle — typically 0.3 mL or 0.5 mL capacity for most doses. The U-100 standard means 100 units per mL, so each unit mark equals 0.01 mL. This is the only syringe type where the tables above apply directly.

For a 2 mg vial reconstituted to 2 mL, a 0.3 mL syringe holds 300 units — enough for up to a 300 mcg dose. If you're dosing at 500 mcg (50 units), you'll need a 0.5 mL syringe.

Needle gauge matters for subQ injection. Common choices: 29G, 30G, or 31G. Thinner needles (31G) cause less injection site discomfort but can be harder to push through the vial stopper during reconstitution. Use a larger needle (25G–27G) for reconstitution, then switch to a fine insulin needle for injection if preferred.

Avoid reusing syringes. Even with the bacteriostatic preservative, each needle stick introduces contamination risk. USP <797> compounding standards emphasize single-use disposables for sterile preparations.

Stability of Reconstituted Tesamorelin

Reconstituted tesamorelin is typically stable for 14–28 days when refrigerated at 2–8°C, depending on the diluent used. Bacteriostatic water with 0.9% benzyl alcohol provides antimicrobial preservation per USP <51>, which is why it's preferred over sterile water — sterile water lacks preservative and should be used immediately or discarded within 24 hours.

The benzyl alcohol in bacteriostatic water serves two functions: it prevents bacterial growth during multi-use storage, and it maintains peptide stability by preventing hydrolysis. The 0.9% concentration is the USP standard for multi-dose injection vials.

Practical guidance: label your vial with the reconstitution date. If you're using 1 mL of diluent and dosing 250 mcg twice weekly, the vial lasts about two weeks — comfortably within the stability window. At higher doses or more frequent injections, you might finish a vial in 5–7 days, which is well within safe limits.

Full Dose Reference Table

For any dose: dose (mcg) ÷ concentration (mcg/mL) = volume (mL), then multiply by 100 for units on a U-100 syringe.

| Target Dose | With 1 mL diluent | With 2 mL diluent | With 3 mL diluent | |---|---|---|---| | 50 mcg | 2.5 units | 5 units | 7.5 units | | 100 mcg | 5 units | 10 units | 15 units | | 150 mcg | 7.5 units | 15 units | 22.5 units | | 200 mcg | 10 units | 20 units | 30 units | | 250 mcg | 12.5 units | 25 units | 37.5 units | | 300 mcg | 15 units | 30 units | 45 units |

The takeaway: 2 mL of diluent is the most user-friendly option for a 2 mg vial. It produces whole-number unit doses for common research doses, keeps injection volumes reasonable, and leaves enough headspace for safe mixing. Choose 1 mL only if injection volume is critical, and 3 mL only if you need fine-grained dosing at low mcg levels.

Where to source bacteriostatic water: Bacteriostatic Water Direct — USP-grade, multi-dose vials; MedSupply Partners — sterile filtration, lot-tracked; Westend Medical Supplies — hospital supply background, bulk options.

Where to source research peptides: Alpha Amino USA — per-lot HPLC/MS COA, US-shipped; PurePeptides Research — third-party tested, lyophilized; ResearchChem Supply — catalog breadth, domestic warehouse.

For research use only — not clinical guidance. Always verify your calculations independently before use.