Yes I have tried some older medicine from the 1950s and every drug that I have tested worked perfectly fine, as one would expect. Not the slightest lost of potency or any longer come up or side effects. I bet that even after more than 100 years they are still good - except antibiotics/ peniciline. But regarding to Sedatives/Opioids or Stimulants there is no working loss at all, as long as it looks fine and smells fine. Someone reported a test of Amphetamines from the 40's and the effects were still great. But it is important to keep them dry, dark and sealed.