Brain altering drugs of any sort are not a good thing for aircrew.
I just got used to time zones, and long-haul aircrew are (usually) given extra days off after trips to recover. You either stay in your original time zone down route, or you adopt the new one, depending how long you will be there.
You have to be disciplined about it and I found that keeping fit helped a lot, along with no smoking and minimal alcohol, i.e. avoiding brain altering drugs.
Setting two independent alarms helped me sleep properly too, since my brain wasn't staying half awake in case the alarm didn't go off.
My brain adapted and if I stay awake much after local midnight - for example when flying back to the UK overnight - it says, "Ah right are we staying up ? OK, that's fine, but I will need some more food"