It may lose a bit of potency but only by a fraction. It will produce relatively the same high as if the pills were brand new. It will produce relatively the same high as if the pills were brand new. I've had experience popping 7 year old Oxycodone and didn't notice any reduction of effects. Hospitals and pharmacies are required to toss expired drugs, no matter how expensive, vital or scarce. And that's even though the FDA has long known that many remain safe and potent for years longer. No. Expired painkillers are perfectly fine. All that happens is they start to lose a tiny % of potency when past the expiration date. It's still the same chemical, perhaps just a tiny bit weaker. This Site Might Help You. RE: Does Percocet (Oxycodone) ever expire or go bad? I just came back from dental surgery and was wondering if this prescription ever expires? Percocet is not oxycodone First, the expiration date, required by law in the United States, beginning in 1979, specifies only the date the manufacturer guarantees the full potency and safety of the drug -- it does not mean how long the drug is actually good or safe to use. The manufacturer states EpiPen autoinjectors should not be used after the expiration date as the epinephrine has been shown to lose its potency. 1 Epipens are used in life-threatening situations like anaphylaxis, so there can be a major health threat with an expired EpiPen. I take old valium and percocet, I usually have them for a couple years because I slowly go through pain killers. It’s never hurt me, and my doctors never told me it was bad. It’s never hurt me, and my doctors never told me it was bad. Hi StrepGirl, I must agree with DzooBaby on this. However, if your Oxycodone pills were NOT stored in a humid area go ahead, if they were stored in a humid place, like the bathroom, you may want to toss them. When people are wondering what happens when you take expired pills, one of the most common drugs they’re referring to is Xanax. With Xanax, an anti-anxiety medication, people will often give or sell their unused pills to friends or family members, and if they’re expired, it can be problematic. Percocet certainly loses potency after that period of time. On dosage, my g/f was prescribed Percocet 5/235 (5mg of opiate, 325mg of APAP) with a dosage of 1-2 every 6 hours with no more than 6 every 24 after having her wisdom teeth extracted.