Hello, Shirley! How are you?

Omeprazole doesn't get dangerous once it's expired, but it may start to lose effectiveness versus when it was new, depending upon how it was stored.

According to Harvard University’s Medical Center, “Most of what is known about drug expiration dates comes from a study conducted by the Food and Drug Administration at the request of the military. With a large and expensive stockpile of drugs, the military faced tossing out and replacing its drugs every few years. What they found from their study is that 90% of more than 100 drugs, both prescription and over-the-counter, were perfectly good to use even 15 years after the expiration date. So, the expiration date doesn't really indicate a point at which the medication is no longer effective or has become unsafe to use. While it's true that the effectiveness of a drug may decrease over time, much of the original potency still remains even a decade after the expiration date.”

Ref: health.harvard.edu/staying-healthy/drug-expiration-dates-do-they-mean-anything

You can also learn more about this medication at: (Omeprazole) MedlinePlus

Hope this helps!