If kept dry, at room temperature and in the dark, it should generally be fine.

See this:

“The box of prescription drugs had been forgotten in a back closet of a retail pharmacy for so long that some of the pills predated the 1969 moon landing. Most were 30 to 40 years past their expiration dates — possibly toxic, probably worthless. ... In his lab, Gerona ran tests on the decades-old drugs, including some now defunct brands such as the diet pills Obocell (once pitched to doctors with a portly figurine called “Mr. Obocell”) and Bamadex. Overall, the bottles contained 14 different compounds, including antihistamines, pain relievers and stimulants. All the drugs tested were in their original sealed containers.

The findings surprised both researchers: A dozen of the 14 compounds were still as potent as they were when they were manufactured, some at almost 100 percent of their labeled concentrations.

“Lo and behold,” Cantrell says, “The active ingredients are pretty darn stable.” ... “We didn’t have any idea that some of the products would be so damn stable — so robustly stable beyond the shelf life,” says Ajaz Hussain, one of the scientists who formerly helped oversee the extension program.”

https://www.propublica.org/article/the-myth-of-drug-expiration-dates