Every compounded medication comes with a date that tells you how long it's expected to remain safe and effective. In the compounding world, this isn't called an "expiration date" — it's called a Beyond-Use Date, or BUD. Understanding what BUD means, how it's determined, and what to do when your medication approaches its BUD can help you make better decisions about your compounded GLP-1 treatment.
BUD vs. Expiration Date: What's the Difference?
Commercially manufactured medications (like brand-name Wegovy or Zepbound) carry expiration dates based on extensive stability studies conducted under FDA-regulated conditions. These studies typically span years and involve testing under various environmental conditions to determine precisely how long the product maintains its labeled potency and quality.
Compounded medications carry Beyond-Use Dates, which serve the same practical purpose but are determined differently. BUDs for compounded sterile preparations (like injectable semaglutide and tirzepatide) are set according to USP <797> standards, and they depend on several factors specific to how and where the medication was prepared.
The Simple Version
Your BUD is the last date you should use your compounded GLP-1 medication. After this date, the pharmacy can no longer guarantee the medication's potency, purity, or sterility. Think of it as the "use by" date on your prescription.
How BUD Is Determined for Compounded GLP-1s
Under USP <797>, the BUD assigned to a compounded sterile preparation depends on several factors:
1. Risk Level of the Compounding Process
USP <797> categorizes compounded sterile preparations based on the contamination risk of the preparation process:
| Category | Description | Default BUD (Refrigerated) |
|---|---|---|
| Category 1 | Simple compounding with commercially sterile ingredients | Up to 12 days (or longer with sterility testing) |
| Category 2 | More complex compounding or non-sterile starting ingredients | Up to 4 days (or longer with sterility testing) |
These default BUDs are conservative starting points. Pharmacies can extend them with appropriate testing.
2. Stability Testing Data
Pharmacies that conduct their own stability studies on their specific formulations can justify longer BUDs. Stability testing involves storing the compounded product under controlled conditions and testing it at regular intervals for potency, pH, sterility, and visual appearance. A pharmacy that has validated its semaglutide formulation to maintain 90%–110% potency for 90 days under refrigeration can assign a 90-day BUD — significantly longer than the default timeframes.
3. Container and Closure System
The type of vial, the rubber stopper quality, and the overall container-closure integrity affect how long the medication remains sterile and stable. Pharmaceutical-grade borosilicate glass vials with validated stoppers provide better protection than generic containers.
4. Storage Conditions
BUDs assume specific storage conditions — typically refrigeration at 36°F–46°F (2°C–8°C). If the medication is stored at room temperature, the applicable BUD is usually shorter. Your pharmacy should clearly state both the refrigerated and room-temperature BUD on the label or accompanying documentation.
What Typical BUDs Look Like for Compounded GLP-1s
In the current market, BUDs for compounded semaglutide and tirzepatide vary based on the pharmacy's testing and quality program:
30–45 days: Common from pharmacies using default USP <797> timeframes without extensive stability testing. This is a conservative but legitimate approach.
60–90 days: Typical from pharmacies that have conducted formulation-specific stability studies. This is the most common range among established compounding operations serving the telehealth GLP-1 market.
120–180 days: Some pharmacies assign extended BUDs based on comprehensive stability data. While this can be legitimate with proper supporting data, very long BUDs (especially 180 days) warrant asking about the stability testing methodology.
Red Flag: Unusually Long BUDs Without Documentation
A pharmacy that assigns a 180-day BUD to a sterile injectable but can't provide stability data supporting that timeframe may be assigning BUDs based on convenience rather than science. Ask for documentation. A reputable pharmacy will be happy to explain how their BUD was determined.
What Happens When Your Medication Reaches Its BUD?
When your compounded GLP-1 reaches its Beyond-Use Date, the pharmacy's guarantee of potency and sterility no longer applies. This doesn't mean the medication instantly becomes dangerous at midnight on the BUD — degradation is a gradual process, not a cliff. However, using medication past its BUD carries increasing risk:
Reduced potency. The semaglutide or tirzepatide may have degraded below its labeled concentration. This means you might be injecting less active medication than you think, which can affect treatment efficacy and confuse dose-response assessment.
Sterility concerns. Over time, especially with multi-dose vials that are repeatedly punctured with a needle, the risk of microbial contamination increases. The BUD accounts for this cumulative exposure risk.
Degradation products. Peptide degradation can produce breakdown products that, while generally not dangerous, may cause increased injection site reactions or reduced tolerability.
The Practical Approach
Don't use medication past its BUD. If you have medication approaching its BUD that you haven't used, contact your provider. Most programs can adjust your shipment schedule to avoid waste. If you're consistently not using your medication before the BUD, it may indicate that your dose frequency or supply quantity needs adjustment.
Multi-Dose Vials: BUD After First Puncture
Many compounded GLP-1 medications come in multi-dose vials that you'll draw from multiple times. The BUD for a multi-dose vial often has two components:
The labeled BUD — the overall expiration of the product from the date of compounding.
The in-use BUD — how long the vial remains safe after you first puncture the stopper with a needle. This is typically 28 days under refrigeration, though some pharmacies may specify different timeframes based on their testing and the preservative content of the formulation.
The effective BUD is whichever date comes first. If your vial has a 90-day BUD from compounding but you first punctured it 28 days ago, the in-use BUD may apply even though the overall BUD hasn't been reached.
Best Practices for Multi-Dose Vials
Write the date you first use the vial on the label with a permanent marker. Use a new alcohol swab to clean the stopper before every injection. Never touch the stopper with your fingers after cleaning it. Always use a fresh, sterile needle for each draw. Inspect the solution before each use — if it's cloudy, discolored, or contains particles, don't use it.
How to Read Your BUD Label
Your compounded GLP-1 vial should display a BUD clearly on the label. Look for:
"BUD:" or "Beyond-Use Date:" or "Use By:" followed by a date. This is the date by which you should use the medication.
"Compounded On:" or "Date Prepared:" — the date the pharmacy prepared your medication. The BUD is calculated from this date.
"Store at:" or "Storage:" — the required storage conditions (typically "Refrigerate 2°C–8°C"). If the label doesn't specify storage conditions, assume refrigeration is required.
If your vial doesn't have a clear BUD label, contact your pharmacy. Proper labeling isn't optional — it's a USP <797> requirement for all compounded sterile preparations.
The Bottom Line on BUD
Beyond-Use Dating is the compounding pharmacy's evidence-based commitment that your medication will work as intended within a specific timeframe. Understanding BUD helps you use your medication safely, avoid waste, and evaluate the quality practices of your compounding pharmacy. A pharmacy that is transparent about how it determines BUD — and can back it up with stability data — is one that takes your safety seriously.