What happens if you inject expired semaglutide?

October 13, 2025 •

4 min read

The U.S. Food and Drug Administration (FDA) began requiring expiration dates on medications in 1979 to ensure product safety and efficacy [1.6.2]. So, what happens if you inject expired semaglutide? Using it past its expiration date poses risks of reduced potency and bacterial contamination [1.2.1, 1.2.3].

Quick Summary

Using expired semaglutide is not recommended. The primary risks include a loss of the drug's effectiveness, meaning it won't manage blood sugar or weight as intended, and a higher chance of bacterial contamination, which can lead to infections.

Key Points

Reduced Effectiveness: Expired semaglutide loses potency, making it less effective for managing blood sugar or weight [1.4.2].
Infection Risk: Preservatives in expired injectable solutions can break down, increasing the risk of bacterial growth and serious infections [1.3.2].
No Safety Guarantee: Manufacturers do not guarantee the safety, strength, or purity of medication after the expiration date [1.2.3].
Proper Storage is Crucial: Unused pens must be refrigerated, while in-use pens can be kept at room temperature for up to 56 days to maintain stability [1.7.1, 1.7.4].
Visual Inspection: Always check that the semaglutide solution is clear and colorless before injecting; discard if it's cloudy or has particles [1.3.5].
Consult a Professional: If you accidentally use expired semaglutide, monitor for adverse effects and contact your healthcare provider for guidance [1.2.2].
Safe Disposal: Use an FDA-cleared sharps container to dispose of expired or used pens and needles to prevent injury [1.7.5, 1.7.7].

Understanding Semaglutide and Its Importance

Semaglutide is a GLP-1 (glucagon-like peptide-1) receptor agonist medication used to manage type 2 diabetes and for chronic weight management under brand names like Ozempic and Wegovy [1.3.1, 1.3.7]. It works by helping the pancreas release the right amount of insulin when blood sugar levels are high, slowing digestion, and reducing appetite [1.3.3, 1.3.2]. For individuals relying on this medication, its consistent performance is crucial for maintaining their health. The manufacturer provides an expiration date to guarantee the drug's strength, quality, and purity up to that point [1.2.3].

The Dangers of Using Expired Injectable Medications

The FDA advises against using any medication past its expiration date [1.6.2]. While some solid-form drugs may retain potency, liquid and injectable medications like semaglutide are more sensitive and present unique dangers [1.4.5, 1.6.4]. The two primary risks associated with injecting expired semaglutide are loss of potency and risk of contamination.

Risk 1: Reduced Potency and Ineffectiveness

After the expiration date, the chemical composition of semaglutide can change, causing it to lose its effectiveness [1.3.2, 1.4.3]. This degradation means the medication may not work as intended [1.4.2].

For Diabetes Management: A less potent dose can lead to poor blood sugar control, potentially causing hyperglycemia (high blood sugar) and other related complications [1.2.3, 1.3.3].
For Weight Management: Reduced effectiveness means the medication may not suppress appetite or promote feelings of fullness as it should, hindering weight loss efforts [1.2.3, 1.3.2].

Manufacturers do not test the stability and potency of drugs beyond their expiration date, so using them is taking an unknown risk [1.2.3, 1.4.5].

Risk 2: Bacterial Contamination and Infection

Injectable medications must be sterile [1.2.1]. Semaglutide solutions contain preservatives to prevent bacterial growth, but these preservatives can weaken over time [1.3.1]. Using an expired vial or pen increases the risk that harmful bacteria or fungi have grown in the solution [1.3.2, 1.4.6].

Injecting a contaminated solution can lead to serious health issues, including:

Local Infections: Redness, swelling, pain, or abscesses at the injection site [1.2.7].
Systemic Infections: In severe cases, bacteria can enter the bloodstream, causing widespread infection (sepsis), which can be life-threatening [1.2.3].

Studies have found that multi-dose medication vials can develop bacterial growth over time, making it critical to adhere to expiration dates [1.2.3]. Always inspect the liquid before use; it should be clear and colorless. If it appears cloudy, has particles, or is discolored, it should be discarded regardless of the expiration date [1.2.4, 1.3.5].

Proper Storage and Handling of Semaglutide

Proper storage is essential to maintain the medication's safety and effectiveness until its expiration date [1.7.3].

Unopened Pens: New, unused semaglutide pens (like Ozempic) should be stored in the refrigerator between 36°F and 46°F (2°C to 8°C) [1.7.1, 1.7.2].
In-Use Pens: After the first use, a pen can typically be stored at room temperature (between 59°F to 86°F or 15°C to 30°C) or in the refrigerator for up to 56 days [1.7.1, 1.7.4].
Protection: Keep the medication away from direct heat, sunlight, and do not freeze it [1.7.1, 1.7.2]. If the pen is frozen, it should not be used.

Expired vs. Unexpired Semaglutide Comparison


Feature	Unexpired Semaglutide	Expired Semaglutide
Potency	Guaranteed by the manufacturer to be fully effective [1.2.3].	May be reduced, leading to ineffective treatment [1.4.2].
Sterility	Preservatives are active, minimizing bacterial risk [1.3.1].	Increased risk of bacterial or fungal growth [1.3.2].
Safety	Considered safe and effective when used as directed [1.6.2].	Safety is not guaranteed; risk of unexpected side effects [1.3.2].
Appearance	Clear, colorless, and free of particles [1.2.4].	May become cloudy, discolored, or contain particles [1.3.5].

What to Do if You've Used Expired Semaglutide

Accidentally using expired semaglutide is not typically a cause for panic, but it requires careful monitoring. While immediate harm is unlikely, the primary risks are a lack of efficacy and potential infection [1.2.5, 1.2.7].

Do not use the pen again. Discard it immediately and safely.
Monitor your symptoms. For those with diabetes, check blood sugar levels more frequently [1.3.3]. Watch the injection site for signs of infection like unusual redness, swelling, pain, or warmth [1.2.7].
Contact your healthcare provider. Inform your doctor or pharmacist about the situation. They can provide guidance based on your health status and advise on the next steps [1.2.2, 1.2.7].

Safe Disposal of Semaglutide Pens

Never throw used or expired pens and needles in the household trash or recycling [1.7.5].

Place used needles and pens in an FDA-cleared sharps disposal container immediately after use [1.7.5, 1.7.7].
If a sharps container is not available, a heavy-duty plastic household container (like a laundry detergent bottle) with a secure lid can be used as an alternative [1.7.7]. Label it clearly as "Hazardous Waste" or "Used Sharps" [1.7.7].
Follow local community guidelines for disposing of the full container, which may include drop-off sites or special waste collection services [1.7.5].

Conclusion

The expiration date on semaglutide is a critical safety measure established by manufacturers and enforced by the FDA [1.6.2, 1.6.5]. While the temptation to use an expensive medication past its prime might be strong, the risks are significant. Injecting expired semaglutide can lead to a less effective treatment, leaving blood sugar uncontrolled or weight loss goals unmet. More seriously, it opens the door to dangerous infections due to potential bacterial contamination [1.2.3, 1.4.2]. Always check the expiration date, store the medication properly, inspect it before each use, and dispose of it safely. Consulting a healthcare professional for a new prescription is the only safe and effective course of action.

For more information on drug safety, you can visit the U.S. Food and Drug Administration (FDA) website.

Frequently Asked Questions

The two main risks are a significant loss of potency, which makes the medication less effective, and an increased risk of bacterial contamination that can lead to infections [1.2.3, 1.4.2].

While it's rare for semaglutide itself to become toxic, the chemical breakdown after expiration means its safety is no longer guaranteed, and it could cause unexpected side effects. The greater risk is from bacterial contamination, not the drug turning toxic [1.2.3, 1.6.1].

Before each use, you should inspect the medication. If it is cloudy, discolored, or contains any visible particles, it has likely gone bad and should not be used, even if it hasn't expired [1.2.4, 1.3.5].

Do not panic. Monitor yourself for any signs of infection at the injection site (redness, swelling, pain) and check your blood sugar levels if you have diabetes. Contact your healthcare provider for advice [1.2.7, 1.3.3].

Once in use, an Ozempic pen can be stored at room temperature or in the refrigerator and should be discarded after 56 days, even if there is still medication left inside [1.7.1, 1.7.4].

No, you should not use semaglutide if it has been frozen. Freezing can affect the medication's integrity. Discard any pen that you know has been frozen [1.7.1, 1.7.2].

You should place the expired pen and any used needles into an FDA-cleared sharps container. Do not throw them in the regular trash. Follow your local community's guidelines for disposing of full sharps containers [1.7.5, 1.7.7].