Does GLP-1 Really Expire After 28 Days? FDA Guidelines Explained

Does GLP-1 really expire after 28 days? This common question reflects widespread confusion about storage guidelines for glucagon-like peptide-1 (GLP-1) receptor agonists used in type 2 diabetes and weight management. The answer is no—there is no universal 28-day rule. Each FDA-approved GLP-1 medication has specific in-use periods ranging from 14 to 56 days after first use or removal from refrigeration. Understanding these product-specific timeframes, which are based on rigorous stability testing, is essential for maintaining medication effectiveness and safety. This article clarifies the actual expiration guidelines for semaglutide (Ozempic, Wegovy), liraglutide (Victoza, Saxenda), dulaglutide (Trulicity), and tirzepatide (Mounjaro, Zepbound).

Understanding GLP-1 Medication Storage and Expiration Guidelines

Glucagon-like peptide-1 (GLP-1) receptor agonists represent a class of medications widely prescribed for type 2 diabetes management and, more recently, for chronic weight management. These injectable medications include semaglutide (Ozempic, Wegovy), dulaglutide (Trulicity), liraglutide (Victoza, Saxenda), while tirzepatide (Mounjaro, Zepbound) is a dual GIP/GLP-1 receptor agonist. A common question among patients concerns the expiration guidelines that appear on these products after first use.

Contrary to popular belief, there is no universal 28-day expiration rule for all GLP-1 medications. Each product has specific FDA-approved in-use periods:

• Ozempic (semaglutide): 56 days at room temperature (up to 86°F/30°C)

• Wegovy (semaglutide): Single-dose pens can be kept at room temperature for up to 28 days

• Victoza and Saxenda (liraglutide): 30 days at room temperature (up to 86°F/30°C)

• Trulicity (dulaglutide): Single-dose pens can be kept at room temperature for up to 14 days

• Mounjaro and Zepbound (tirzepatide): Single-dose pens can be kept at room temperature for up to 21 days

These timeframes are not arbitrary but reflect manufacturer testing and FDA approval conditions based on stability data. When pharmaceutical companies develop injectable biologics, they conduct extensive stability studies under various storage conditions to determine how long the medication maintains its potency, sterility, and safety profile.

It is important to distinguish between the printed expiration date on an unopened pen and the in-use expiration that begins once you administer the first dose (for multi-dose pens) or remove from refrigeration (for single-dose pens). An unopened pen stored continuously in the refrigerator remains viable until the manufacturer's printed expiration date, which is typically one to two years from the production date.

Patients should always consult the FDA-approved prescribing information and medication guide specific to their medication, as storage requirements and in-use timeframes vary between different products.

Why GLP-1 Medications Have Specific Use Windows After Opening

The specific in-use time limitations for GLP-1 medications stem from multiple factors related to the chemical stability and microbiological safety of these complex biologic drugs. Unlike small-molecule medications that may remain stable for extended periods, peptide-based therapeutics like GLP-1 agonists are susceptible to degradation through several mechanisms.

Chemical degradation represents the primary concern. GLP-1 receptor agonists are modified peptides or peptide analogs that can undergo structural changes when exposed to temperature variations, light, and oxidation. These modifications may reduce the medication's potency, meaning you might receive less than the intended therapeutic dose. Pharmaceutical stability testing determines the specific in-use period for each product—ranging from 14 to 56 days depending on the formulation—during which the medication maintains acceptable potency under typical use conditions.

Microbiological contamination poses another significant risk factor, particularly for multi-dose pens. Each time a needle pierces the pen's rubber seal, there exists a theoretical risk of introducing bacteria or other microorganisms. To minimize this risk:

• Always use a new needle for each injection

• Never store pens with the needle attached

• Never share pens with others, even if you change the needle

• Always recap the pen after use

While the medication contains preservatives in some formulations, these antimicrobial agents have limits to their protective duration and effectiveness. The FDA-approved in-use period provides a safety margin that minimizes the risk of bacterial growth that could lead to injection site infections or systemic complications.

Additionally, physical changes in the formulation may occur over time. Some GLP-1 medications are clear solutions that should remain transparent throughout their use period. Protein aggregation, precipitation, or particulate formation can develop with extended storage, potentially affecting both safety and efficacy. Manufacturers establish specific in-use guidelines based on when these physical changes become more likely to occur, even if not yet visible to the naked eye.

What Happens If You Use GLP-1 Beyond the Labeled In-Use Period

Using a GLP-1 medication beyond its FDA-approved in-use period is not recommended under any circumstances. The labeled in-use periods (which range from 14 to 56 days depending on the specific product) are established based on comprehensive stability and safety testing, and using medication beyond these timeframes introduces uncertainty regarding both effectiveness and safety.

Reduced therapeutic efficacy represents a significant concern when using expired GLP-1 medication. As the peptide degrades, the concentration of active drug decreases, potentially resulting in suboptimal glycemic control for patients with type 2 diabetes or diminished weight loss effects for those using these medications for obesity management. Patients might notice their blood glucose levels trending upward or weight loss plateauing or reversing.

While the degradation process is gradual rather than sudden at the expiration point, the FDA-approved in-use period represents the timeframe during which the manufacturer guarantees the medication's potency and safety. Using medication beyond this period means you may not receive the full prescribed dose, potentially compromising your treatment outcomes.

Potential safety concerns include the risk of using medication that has been contaminated due to improper storage or repeated needle insertions over an extended period. Signs of infection following injection—such as increasing redness, warmth, swelling, or purulent drainage—warrant immediate medical evaluation.

Patients who discover they have inadvertently used medication beyond the labeled in-use period should contact their healthcare provider or pharmacist for guidance. In most cases, obtaining a fresh pen and monitoring for adequate therapeutic response represents the appropriate course of action. Healthcare providers can also provide guidance on proper disposal of expired medication and may be able to help with insurance coverage for replacement medication if needed.

Always follow the specific in-use period for your medication as stated in the FDA-approved prescribing information and medication guide.

Proper Storage Practices to Maintain GLP-1 Effectiveness

Maximizing the stability and effectiveness of GLP-1 medications throughout their in-use period requires attention to specific storage conditions and handling practices. Following FDA-approved storage guidelines ensures you receive the full therapeutic benefit of these medications while minimizing safety risks.

Refrigeration requirements form the foundation of proper GLP-1 storage. Unopened pens should be stored in the refrigerator at temperatures between 36°F and 46°F (2°C to 8°C). Keep the medication in its original carton to protect it from light exposure. Avoid storing GLP-1 pens in the refrigerator door, where temperature fluctuations occur most frequently with opening and closing. Instead, place them on a middle shelf toward the back where temperature remains most stable.

Once in use, most GLP-1 medications can be kept at room temperature (up to 86°F or 30°C) for their specific in-use period:

• Ozempic (semaglutide): 56 days at room temperature

• Victoza/Saxenda (liraglutide): 30 days at room temperature

• Wegovy (semaglutide): Single-dose pens for up to 28 days at room temperature

• Trulicity (dulaglutide): Single-dose pens for up to 14 days at room temperature

• Mounjaro/Zepbound (tirzepatide): Single-dose pens for up to 21 days at room temperature

Key storage practices include:

• Never freeze GLP-1 medications; freezing permanently damages the peptide structure

• If accidentally frozen, discard the pen even if it later thaws

• Keep pens away from direct sunlight and heat sources

• Remove the pen from the refrigerator 15-30 minutes before injection if you prefer room-temperature administration

• Always replace the pen cap after each use to protect from light

• Remove the needle after each injection; never store with needle attached

• Never share pens with others, even if changing the needle

• Store pens in a secure location away from children and pets

Travel considerations require special planning. When flying, keep your medication in carry-on luggage rather than checked baggage, where freezing temperatures in cargo holds could damage the drug. The Transportation Security Administration (TSA) allows injectable medications and related supplies through security checkpoints. Use an insulated medication travel case with ice packs for extended trips, ensuring the medication does not directly contact ice. Carry a copy of your prescription and a letter from your healthcare provider when traveling internationally.

Documentation practices help ensure you use medication within the appropriate timeframe. Write both the first-use date and the product-specific discard date directly on the pen label. For example, if you start an Ozempic pen on January 1, write "First use: 1/1, Discard after: 2/26" (56 days later). Set a reminder on your phone for the appropriate discard date to prompt timely replacement.

Signs Your GLP-1 Medication May No Longer Be Safe to Use

Recognizing visual and physical indicators that a GLP-1 medication has degraded or become contaminated is essential for patient safety. While the FDA-approved in-use periods provide time-based safety parameters, certain observable changes should prompt immediate discontinuation regardless of how long the pen has been in use.

Visual inspection should occur before every injection. Most GLP-1 formulations are clear, colorless to slightly yellow solutions. Examine the medication window on your pen carefully under good lighting. Discard the medication immediately if you observe:

• Cloudiness or turbidity in normally clear solutions

• Visible particles, flakes, or floating material

• Color changes, particularly darkening or unusual discoloration

• Crystallization or precipitation

• Separation of the solution into layers

These changes indicate chemical degradation or contamination that renders the medication unsafe for use. Do not attempt to use the medication even if it is within the labeled in-use period, as these physical changes suggest the formulation has been compromised.

Functional indicators may also signal problems with your GLP-1 pen. If the injection mechanism becomes difficult to operate, the dose counter malfunctions, or medication does not flow properly during injection, the pen may be damaged. Additionally, if you notice an unusual odor when removing the cap (though GLP-1 medications are typically odorless), this could indicate contamination.

Storage history should factor into your assessment. If you discover that your medication was accidentally left at temperatures above 86°F (30°C), was exposed to direct sunlight, or was frozen, it should be discarded regardless of appearance. The FDA-approved labeling for each product specifies maximum allowable time at room temperature, typically ranging from days to weeks depending on the formulation.

Patients experiencing unexpected injection site reactions—such as severe pain, extensive redness, swelling, or signs of infection—should discontinue use and seek medical evaluation. While these reactions can occasionally occur with properly stored medication, they may indicate contamination in medication that has been stored improperly or used beyond its safe period.

When in doubt about medication integrity, contact your pharmacist or healthcare provider before administering a dose. Contact your pharmacist, insurance provider, or the manufacturer's patient support program to inquire about options for replacing questionable medication. Proper disposal of expired or damaged GLP-1 pens should follow FDA guidelines for injectable medications, typically involving placement in an FDA-cleared sharps container or following specific take-back programs available through pharmacies.

Frequently Asked Questions