Why Does Trelegy Expire After 6 Weeks?
In our latest question and answer, our pharmacist discusses why Trelegy expires 6 weeks after opening.

Question
Why do I have to throw away Trelegy after 6 weeks? Is it not safe to use then?

Answered by Dr. Brian Staiger, PharmD
Medical Content Reviewed By HelloPharmacist
Staff
Last updated Apr 19, 2025
Key points
- Trelegy Ellipta expires 6 weeks after being removed from the foil pack due to medication stability and efficacy concerns.
- Adherence to the expiration date ensures optimal drug effectiveness and reduces the risk of potential harm.
Quick Answer
You are correct that Trelegy expires 6 weeks after it has been removed from its foil pack. This 6-week expiration date is based on stability data for the drug. Using it past the expiration date may result in the drug not being as effective as it once was.
Detailed Answer
According to the prescribing information for Trelegy, it expires 6 weeks after the device has been removed from the foil tray:
TRELEGY ELLIPTA should be stored inside the unopened moisture-protective foil tray and only removed from the tray immediately before initial use. Discard TRELEGY ELLIPTA 6 weeks after opening the foil tray or when the counter reads “0” (after all blisters have been used), whichever comes first. The inhaler is not reusable. Do not attempt to take the inhaler apart.
The expiration of Trelegy Ellipta being 6 weeks after it is removed from the foil wrap is primarily due to the need to maintain medication stability and this expiration timeframe date is established through rigorous stability testing conducted by the manufacturer. The foil wrapping around the device protects it from environmental factors (such as humidity) that can degrade the drug and once that wrapping is removed, the expiration countdown begins.
While it is possible that the medication may retain some effectiveness after 6 weeks, there is no scientific data to support its efficacy beyond the specified expiration date.
It is important to note that expiration dates are not arbitrary; they are established based on scientific data and regulatory requirements. Using a medication beyond its expiration date may result in reduced efficacy or potential harm if you take into account your disease state (asthma or COPD in this case) not being adequately treated.
So, I would say that Trelegy isn't safe to use after this 6-week expiration. There is no evidence to suggest the drug itself will be harmful after it expires, but rather, it may not be as effective as it once was and may not work as well to treat your condition.
Only Open Trelegy When You Are Ready To Use It
Trelegy comes in two different strengths, and each strength device contains 30 doses in total.
Although a 6-week expiration may not sound like a long time, since Trelegy is recommended to be dosed once daily, you shouldn't have a problem with the drug expiring if you only open the package when you are ready to use it and use it as directed.
You'll be finished with the 30 doses in 30 days, and not have to worry about 6 weeks passing and the drug expiring.
Final Words
I hope this answer helped provide the insight you were looking for!
Feel free to reach back out anytime.
References
- Trelegy Prescribing Information, GSKPro
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Dr. Brian Staiger, PharmD
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