"i was born with arthritis and have been on many of the narcotic based drugs in my 20  years of being treated.  i noticed someone saying that methadone makes them feel tired when they sit.  i know that is a normal side effect but i urge all men that are taking any narcotic pain medication to get your testosterone checked!  narcotics lower the level of testoserone and that makes you feel very tired.  i was feeling very tired all the time and didn&#039;t really have any get-up-and-go and would have &quot;hot flashes.&quot;  i got my levels checked and my testosterone was almost at female levels.  now i get testosterone shots and feel much better.  if you are on medicines long term, get your levels checked!"