Understanding Semaglutide and Its Forms
Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist, a class of medication used to improve glycemic control in adults with type 2 diabetes and for chronic weight management [1.9.1, 1.9.4]. It works by stimulating insulin secretion, slowing down stomach emptying, and reducing appetite [1.9.1]. Semaglutide is a protein-based molecule, which makes it sensitive to temperature and environmental conditions [1.3.3, 1.10.5].
This medication comes in several forms, each with specific storage rules:
- Compounded Semaglutide: Often dispensed in multi-dose vials from a compounding pharmacy. These are not FDA-approved but are prepared by licensed pharmacies [1.2.2, 1.5.2].
- Ozempic®: An FDA-approved, brand-name, multi-dose injectable pen used primarily for type 2 diabetes [1.3.1, 1.9.1].
- Wegovy®: An FDA-approved, brand-name, single-dose injectable pen used for chronic weight management [1.4.3, 1.9.1].
The Critical Role of Proper Storage
Proper storage is essential to maintain the medication's stability, effectiveness, and safety [1.8.1]. Semaglutide's protein structure can be damaged by extreme temperatures (both heat and freezing), causing it to lose potency [1.3.3, 1.6.4]. Improper storage can lead to reduced effectiveness, meaning it may not control blood sugar or aid in weight loss as intended [1.6.1, 1.10.4]. Furthermore, it increases the risk of bacterial contamination, which could lead to infections [1.6.1, 1.6.2]. The ideal refrigeration temperature for semaglutide is between 36°F and 46°F (2°C to 8°C) [1.8.1]. It should never be frozen [1.3.3].
Shelf Life After Opening: Vials vs. Pens
The answer to "How long is a semaglutide vial good for in the fridge?" varies significantly between compounded vials and brand-name pens.
Compounded Semaglutide Vials
Once a multi-dose vial of compounded semaglutide is opened (punctured for the first time), it is typically good for 28 days when stored in the refrigerator [1.2.1, 1.5.2]. Unopened vials should be kept refrigerated and are safe to use until the expiration date printed on the vial by the pharmacy [1.2.1]. However, these guidelines can vary depending on the specific formulation and preservatives used by the compounding pharmacy, so it is crucial to check the label and follow the pharmacy's specific instructions [1.5.2].
Ozempic® Multi-Dose Pens
Unopened Ozempic pens must be stored in the refrigerator until their first use and are good until the manufacturer's expiration date [1.3.2]. After the first use, an Ozempic pen has a much longer in-use life. It can be stored for up to 56 days [1.3.1]. During this 56-day period, the pen can be kept either in the refrigerator or at room temperature (between 59°F and 86°F or 15°C to 30°C) [1.3.2, 1.3.4].
Wegovy® Single-Dose Pens
Unopened Wegovy pens should be stored in the refrigerator (36°F to 46°F) [1.4.3]. If needed, an unopened pen can be kept at room temperature (up to 86°F) for up to 28 days before use [1.4.1, 1.4.4]. Wegovy pens are designed for a single use only. After administering the dose, the entire pen should be discarded immediately in a sharps container; there is no "after opening" storage period [1.4.1, 1.4.3].
Comparison of Semaglutide Storage Rules
| Medication Type | Storage Before First Use | Storage Duration After First Use | Temperature After First Use |
|---|---|---|---|
| Compounded Vial | Refrigerated (36°F - 46°F) until expiration date [1.2.1]. | Typically 28 days [1.5.2]. | Must remain refrigerated [1.5.2]. |
| Ozempic® Pen | Refrigerated (36°F - 46°F) until expiration date [1.3.2]. | 56 days [1.3.1]. | Refrigerator or Room Temp (59°F - 86°F) [1.3.2]. |
| Wegovy® Pen | Refrigerated (36°F - 46°F). Can be at room temp for up to 28 days if needed before use [1.4.1]. | N/A (Single-use) [1.4.1]. | Discarded immediately after use [1.4.1]. |
How to Tell if Semaglutide Has Gone Bad
Regardless of the date, you should always visually inspect your semaglutide solution before each injection. Properly stored, the liquid should be clear and colorless [1.7.2]. You should discard the medication if you observe any of the following signs [1.7.1, 1.7.2, 1.7.3]:
- The solution is cloudy or discolored.
- There are particles, crystals, or clumps floating in the liquid.
- The pen or vial has been frozen.
- The pen or vial has been exposed to temperatures above 86°F (30°C) [1.3.3].
Risks and Proper Disposal
Using expired or improperly stored semaglutide is not recommended. The primary risks include a significant loss of potency, which can lead to ineffective treatment for diabetes or weight management [1.6.1, 1.6.5]. There is also a risk of bacterial growth in the solution, which can cause serious infections [1.6.1]. The chemical breakdown of the drug could also potentially cause unknown side effects [1.6.2].
Always dispose of used needles, pens, and vials safely. Use an FDA-cleared sharps disposal container [1.3.1]. If one is not available, a heavy-duty, puncture-resistant plastic container with a secure lid can be used [1.4.3]. Follow your local community guidelines for proper disposal of sharps containers [1.6.1].
Conclusion
The stability of your semaglutide medication hinges on correct storage. While a compounded semaglutide vial is generally good for 28 days in the fridge after opening, FDA-approved pens like Ozempic and Wegovy have different rules, with a 56-day in-use life for Ozempic and a single-use design for Wegovy. Always verify the specific instructions provided by your pharmacy or on the medication's packaging to ensure you are receiving a safe and effective dose every time.
