Does Ativan lose strength after a while?

The medication is unlikely to have lost its potency, but please be aware that Ativan is physically addictive and can be difficult to withdraw from without proper guided titration.
Also dose plays a significant role in dependence to Ativan, and people are often under the idea that because the typical 1mg dose seems low that they are not taking much but even at low levels it is highly addictive.
Be careful and I hope you feel better.

They should be good for a year or so after their expiry date without question at the very least. I suspect that you have gained a tolerance to a proved habit forming medication. Ativan equals medication prisoners in my opinion.
Good luck with it.