Tesamorelin, a synthetic peptide used to treat excess abdominal fat in adults with HIV-associated lipodystrophy, is most commonly administered as a subcutaneous injection. It is a lyophilized (freeze-dried) powder that must be reconstituted with a diluent before use. How long a vial lasts is not a single answer, as it depends entirely on the specific brand and formulation prescribed. The most critical distinction is between the daily-use and weekly-use products.
Understanding Tesamorelin Vial Durations
The duration of a tesamorelin vial is divided into two phases: its life in its original, lyophilized powder form and its life as a reconstituted liquid. The storage and stability guidelines are different for each phase and differ between products.
Daily Tesamorelin (Egrifta SV)
For the daily-use formulation, Egrifta SV®, the instructions for use are very clear and strict. This version comes as a single-dose vial that must be used immediately after reconstitution. Once the sterile water diluent is added and the powder is mixed, the solution must be administered right away. Any unused portion of the mixed solution, no matter how small, must be discarded immediately. This means that for Egrifta SV, the vial technically only lasts for a few minutes after mixing. Unopened Egrifta SV vials, however, are stable for long-term storage under refrigeration, between 2°C and 8°C (36°F and 46°F), until their manufacturer's expiration date.
Weekly Tesamorelin (Egrifta WR)
In contrast, the weekly-use formulation, Egrifta WR™, is designed for greater convenience and has a longer stability period after reconstitution. This product is mixed once a week, and the reconstituted vial contains enough doses for seven daily injections. Once mixed, the vial is stable for up to seven days, provided it is stored correctly. After the seven-day period, any remaining medication must be thrown away. Unlike the daily version, Egrifta WR can be stored at room temperature, between 20°C to 25°C (68°F to 77°F), both before and after mixing.
Compounded Tesamorelin Preparations
Some individuals may receive tesamorelin from a compounding pharmacy. These preparations might have different stability instructions than the FDA-approved brand-name versions. A manufacturer or compounding pharmacy may suggest a stability period of several weeks for a refrigerated, reconstituted vial. However, it is essential to follow the instructions provided by the specific compounding pharmacy and not assume that the stability matches an FDA-approved product. The guidelines for FDA-approved medications like Egrifta SV and Egrifta WR are based on rigorous testing, ensuring safety and efficacy. If you receive a compounded product, you must consult your pharmacist for precise storage and usage information.
Comparison of Tesamorelin Formulations
To highlight the crucial differences in vial longevity, a comparison table can be helpful. This table summarizes the key storage aspects of the two FDA-approved tesamorelin products.
| Feature | Egrifta SV® (Daily) | Egrifta WR™ (Weekly) |
|---|---|---|
| Dosing Frequency | Once per day | Once per day |
| Reconstitution Frequency | Once per day | Once per week |
| Pre-Reconstitution Storage | Refrigerated (2-8°C / 36-46°F) | Room temperature (20-25°C / 68-77°F) |
| Post-Reconstitution Stability | Use immediately | Stable for 7 days |
| Post-Reconstitution Storage | Discard immediately | Room temperature (20-25°C / 68-77°F) |
Critical Storage and Handling Instructions
Regardless of the formulation, several universal guidelines apply to ensure the safety and efficacy of tesamorelin.
Handling Unopened Vials
- Read the Label: Always follow the storage instructions provided on the packaging for your specific product.
- Avoid Freezing: Never freeze tesamorelin vials, whether reconstituted or in powder form.
- Protect from Light: Keep the vials in their original packaging and away from direct light to prevent degradation of the peptide.
Handling Reconstituted Solution
- Gentle Mixing: To mix the powder with the diluent, gently roll the vial in your hands; do not shake vigorously. Shaking can damage the sensitive peptide structure.
- Visual Inspection: Before injecting, visually inspect the solution. It should be clear and colorless. If it appears cloudy, discolored, or contains particles, do not use it.
- Single-Use Diluent: For some products like Egrifta SV, the diluent is single-use and must also be discarded after the injection. For Egrifta WR, the bacteriostatic water diluent can be used for 28 days after first use.
- Proper Disposal: Use a new, sterile needle and syringe for each dose and dispose of all used materials in a puncture-resistant sharps container. Never reuse or share injection supplies.
Factors Influencing Tesamorelin Stability
Tesamorelin is a delicate peptide hormone, and its stability is influenced by several factors, including the act of reconstitution, temperature, and light exposure. Once reconstituted with a solvent, the peptide is much more susceptible to degradation compared to its stable, lyophilized powder form. High temperatures and repeated temperature changes (like frequent removal from a refrigerator) can further break down the active ingredient. This is why adherence to storage protocols and understanding the specific product's shelf-life is essential to maintain therapeutic effectiveness.
Conclusion
The question of how long does a vial of tesamorelin last has two distinct answers depending on the product being used. For the daily, single-use Egrifta SV, the vial is only viable for immediate use after reconstitution, and any remainder must be discarded. In contrast, the weekly Egrifta WR vial remains stable for seven days after mixing and can be stored at room temperature. For any compounded formulations, the duration can vary, making it essential to consult with your pharmacist. Following the specific storage and handling instructions provided with your prescription is paramount to ensuring the medication is safe and effective throughout your treatment. For comprehensive patient information and instructions, refer to reliable sources like the official FDA prescribing information.
