Tesamorelin is a 44-amino-acid growth hormone releasing hormone (GHRH) analog that reconstitutes with bacteriostatic water using the same general technique as other lyophilized research peptides — water added to the vial wall, gentle swirling, refrigerated storage. The dose math differs from shorter GHRH analogs like sermorelin because community-cited tesamorelin protocols document daily doses in the 1-2 mg range rather than the 100-300 mcg range, which changes the concentration target and syringe-unit mapping.
Research-context information only. Tesamorelin has FDA approval for one specific indication (HIV-associated lipodystrophy) as a finished pharmaceutical product. The reconstitution math below applies to research-format lyophilized vials sold by peptide vendors, not the FDA-approved finished product. Community protocols, doses, and handling notes reported here come from vendor documentation and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.
The FDA-approved finished product ships as a kit with pre-measured diluent. Research-format tesamorelin vials — sold lyophilized in 2mg, 5mg, and 10mg sizes — require the user to source bacteriostatic water separately and calculate the reconstitution ratio. The math below covers those research-format vials.
How much bacteriostatic water for tesamorelin
Research-format tesamorelin is sold as a lyophilized powder in glass vials sealed with rubber stoppers and metal crimps. The most common vial sizes across vendors are 2mg, 5mg, and 10mg. The reconstitution ratio determines the final concentration in mg/mL, which determines how many U-100 syringe units correspond to each dose step community protocols document.
Reconstitution table — all documented vial sizes
| Vial size | Bac water added | Concentration | 1 mg dose (units) | 2 mg dose (units) | Notes |
|---|---|---|---|---|---|
| 2 mg | 2 mL | 1 mg/mL | 100 units | 200 units (2 draws) | Most-cited ratio; clean unit math for 1 mg step |
| 2 mg | 1 mL | 2 mg/mL | 50 units | 100 units | Halves injection volume; 2 mg fits a single syringe |
| 5 mg | 5 mL | 1 mg/mL | 100 units | 200 units (2 draws) | Matches 2mg-vial math; larger vial extends between-vial intervals |
| 5 mg | 2.5 mL | 2 mg/mL | 50 units | 100 units | 2 mg in a single 100-unit draw; most practical for daily 2 mg protocols |
| 10 mg | 5 mL | 2 mg/mL | 50 units | 100 units | Community-preferred for 2 mg daily; 5 days per vial at 2 mg/day |
| 10 mg | 10 mL | 1 mg/mL | 100 units | 200 units (2 draws) | Dilute option; matches smaller-vial 1 mg/mL math |
Community sources most commonly cite two concentration targets:
- 1 mg/mL — clean unit math (each 10-unit mark = 0.1 mg), but the 2 mg daily dose cited in most community protocols requires 200 units, exceeding a single U-100 syringe.
- 2 mg/mL — the 2 mg daily dose fits in a single 100-unit draw. Community sources cite this as the more practical concentration for users documenting the 2 mg daily dose step.
The choice between concentrations is a trade-off between per-unit precision and injection convenience. Both are widely documented across vendor reconstitution sheets.
U-100 syringe unit mapping at 2 mg/mL
| Dose | Syringe units (U-100) | Volume (mL) |
|---|---|---|
| 0.5 mg | 25 units | 0.25 mL |
| 1 mg | 50 units | 0.50 mL |
| 1.5 mg | 75 units | 0.75 mL |
| 2 mg | 100 units | 1.00 mL |
U-100 syringe unit mapping at 1 mg/mL
| Dose | Syringe units (U-100) | Volume (mL) |
|---|---|---|
| 0.5 mg | 50 units | 0.50 mL |
| 1 mg | 100 units | 1.00 mL |
| 1.5 mg | 150 units (2 draws) | 1.50 mL |
| 2 mg | 200 units (2 draws) | 2.00 mL |
Step-by-step reconstitution as documented in community sources
The sequence below reports the steps community reconstitution sheets and vendor instruction inserts most commonly describe. It is not an instruction set.
- Surface preparation. Both vial tops — tesamorelin and bacteriostatic water — are wiped with separate alcohol swabs and allowed to air-dry. Community sources commonly cite 10 to 30 seconds of dry time.
- Bacteriostatic water draw. A fresh syringe is used to draw the documented water volume. For a 2mg vial at 1 mg/mL, that is 2 mL; for a 5mg vial at 2 mg/mL, that is 2.5 mL. Volumes above 1 mL require a syringe larger than a standard U-100 insulin syringe or multiple draws.
- Water injection at the vial wall. The needle is inserted into the tesamorelin vial at an angle aimed at the glass wall — not directly at the lyophilized powder. Community sources cite the side-wall approach as the standard practice for protecting peptide integrity.
- Gentle dissolution. The vial is swirled with a slow rotating motion rather than shaken. Community sources and vendor documentation describe tesamorelin dissolving within 1 to 3 minutes into a clear, colorless solution. The 44-amino-acid chain dissolves more slowly than smaller peptides — patience and gentle technique are documented as the standard approach.
- Refrigerated storage. The reconstituted vial is moved to refrigeration at 2 to 8 degrees Celsius immediately after reconstitution. Community sources cite prompt refrigeration rather than leaving the vial at room temperature.
How tesamorelin reconstitution compares to related GHRH analogs
Tesamorelin belongs to the GHRH analog class alongside sermorelin and CJC-1295 — but the reconstitution math differs because of the dose range. Sermorelin and CJC-1295 community protocols document doses in the 100-300 mcg range; tesamorelin protocols document doses in the 1-2 mg range — roughly 10x higher by mass. This means:
- Sermorelin and CJC-1295 reconstituted at 1 mg/mL produce dose steps that fit easily within a U-100 syringe (100 mcg = 10 units, 300 mcg = 30 units).
- Tesamorelin reconstituted at 1 mg/mL produces dose steps that push against or exceed the syringe capacity (1 mg = 100 units, 2 mg = 200 units).
Community sources cite this difference as the reason 2 mg/mL is more commonly documented for tesamorelin than for sermorelin or CJC-1295, where 1 mg/mL is the dominant concentration target.
Storage after reconstitution
USP guidance describes a 28-day multi-dose window for bacteriostatic water under aseptic technique. Community sources and vendor documentation commonly cite the same 28-day window for reconstituted tesamorelin held continuously refrigerated at 2 to 8 degrees Celsius.
The conditions community reconstitution sheets cite as the documented storage protocol:
- Temperature: 2 to 8 degrees Celsius (refrigerator, not freezer)
- Light: protected from direct light; vials kept in the original carton or opaque container
- Movement: minimal disturbance; vials not stored in the refrigerator door where temperature cycling is greatest
- Aseptic technique: alcohol swab on the stopper before every puncture; fresh insulin syringe per draw
- Multi-dose window: 28 days per USP guidance for bacteriostatic water
Lyophilized (unreconstituted) tesamorelin vials are typically more stable than reconstituted ones. Community sources cite long-term storage of unreconstituted peptide at freezer temperatures (-20 degrees Celsius or below) as the standard approach for vials that will not be reconstituted within a few months.
Common mistakes community sources cite
Several handling failures appear repeatedly in community reconstitution reports and vendor support threads. The list below reports what community sources describe, not instruction.
- Shaking the vial instead of swirling. Tesamorelin is a 44-amino-acid peptide chain — longer than most growth-hormone secretagogues. Community sources commonly cite aggressive shaking as a denaturation risk, particularly for longer-chain peptides where tertiary structure matters for receptor binding.
- Injecting water directly onto the lyophilized cake. Direct-stream injection onto the powder has been cited as a mechanical-damage source. Community sheets describe aiming the water stream at the glass wall instead.
- Reconstituting at 1 mg/mL without accounting for the 2 mg dose step. At 1 mg/mL, the 2 mg daily dose documented in most community protocols requires 200 units — exceeding the 100-unit capacity of a standard U-100 insulin syringe. Community sources describe this as the most common math error for users transitioning from sermorelin or CJC-1295 reconstitution habits, where 1 mg/mL works cleanly.
- Using non-USP bacteriostatic water. Community sources commonly cite cloudy-vial outcomes traced to bacteriostatic water sourced from marketplace listings that lack USP labeling, lot tracking, or 0.9% benzyl alcohol confirmation.
- Storing at room temperature between doses. Community degradation reports cluster around room-temperature storage as the most common contributing factor to cloudiness and particulate formation within the 28-day window.
- Freeze-thaw cycling of reconstituted vials. Frozen and re-thawed peptide solutions are repeatedly cited in community sources as producing visible cloudiness on rewarming. The 2 to 8 degrees Celsius range — not below — is the documented storage target for reconstituted product.
Vial yield at community-cited dose levels
At the community-cited 2 mg daily dose, vial yield varies significantly by size:
| Vial size | Days per vial at 2 mg/day | Days per vial at 1 mg/day |
|---|---|---|
| 2 mg | 1 day | 2 days |
| 5 mg | 2.5 days | 5 days |
| 10 mg | 5 days | 10 days |
Community sources note that the 2mg vial is effectively single-dose at the 2 mg/day level, which is why 5mg and 10mg vials are more commonly cited in community purchasing documentation — they provide multi-day coverage within the 28-day window. The 10mg vial at 2 mg/day yields 5 days of coverage, meaning roughly 6 vials per month at the upper community-cited dose.
Bottom line
Tesamorelin reconstitutes with bacteriostatic water using vendor-documented and community-cited ratios that depend on vial size and target concentration. The most practical concentration for the 2 mg daily dose step documented in community protocols is 2 mg/mL — produced by 1 mL into a 2mg vial, 2.5 mL into a 5mg vial, or 5 mL into a 10mg vial — which fits the full dose into a single 100-unit insulin syringe draw. The 1 mg/mL alternative is widely documented but requires two draws for the 2 mg dose. USP guidance describes a 28-day window for the bacteriostatic water itself; community sources cite continuous refrigeration at 2 to 8 degrees Celsius with light shielding as the standard approach.
Related reading
- Tesamorelin Dosing Guide — full protocol documentation on thepeptidecatalog
- What Is Bacteriostatic Water? Benzyl Alcohol + Uses (2026) — composition, USP standards, benzyl alcohol mechanism
- How Long Does Bacteriostatic Water Last? 28-Day Rule (2026) — the post-puncture window and storage variables
- How Much Bac Water per Vial? Universal Charts (2026) — reconstitution math for every standard vial size
- Insulin Syringe Units to mL Conversion (2026) — unit-to-volume mapping for accurate dose calculation
- Bac Water for Sermorelin, CJC-1295, Ipamorelin (2026) — sibling GHRH-analog reconstitution math for comparison
This guide is for educational and informational purposes only. It is not medical advice. Bacteriostatic water for injection is a regulated injectable product subject to FDA labeling standards. As an affiliate partner, The Peptide Catalog may earn a commission on qualifying purchases at no extra cost to the reader. Bacteriostatic water is sold for research and professional use only.