As instructor I did see many unwaited students' mistakes and allways searched what was wrong that day, that flight : mostly
- not correct sleep
- use of any pill said to have no counter-effect .
Forget pills definitively. If you are tired inform your airline you are not fit and don't fly.
Learn how much sleep YOU need : start during holidays; go to bed when you feel asleep, no alarm, and watch at which time you wake up. Stand up and start your day. You will discover that during your sleep you may have some half wake-up, the next day you remember you listened the church or wrote a word on a paper, aso but felt asleep again easily. You will see that that sleep part has a specific duration (for me it is around 1½ hour, for other it will be 2 hours). Then you will discover that your real wake-up needs a round number of such cycles or a bit more. For me it happens after three cycles around five hours. That is my normal sleep time. Many people need around 7 hours.
If I need to have a shorter sleep it will be 3 hours : NEVER cut any short cycle with an alarm or otherwise.
If a was very tired by the day, or when I was working by night the whole week (as freightdog) I will need 7 hours (4 short cycles).
Observe yourself. I need to sleep the two first short cycles together, and sleeping more than 7 hours destroys my whole day : I shall be like a zombie, and feel bad.
Now during work time schedules are irregular. Keep always in sight your cycles' need. Flying by night is not the same as flying by day : sleep is normally regulated by body temperature. Colder to sleep, warmer to work. Regulation of temperature is disturbed by your schedules and the outside light oscillation . Take a 10 minutes bath with decreased temperature ½°c lower than your actual body before going to sleep if it is daytime. No pill .
If you change your time zone, some days (2-3 days ) before your flight prepare your body :
- modify the schedule of your salted meals at the wanted new schedule
- go to bed (probably you will not sleep but manage a quiet life lying) to take "rest" despite it is often said that we cannot rest before to be tired : false, we may accumulate some prerest, and it is not necessfull to sleep, but stay in your bed try to "dream" (possible without to sleep! )
Sometimes demanding tasks increases the need to rest : learn and train some naps: I am able to do without alarm a 3 minutes and a 15 minutes nap.
Caffeine ? Normally it will just disturb your brain work ! If you like coffee drink only the best : Arabica at regular times.
All that works if you are fit without pathology which is normally the case for pilots.
Overall forget pills when you are a flying crew. Medics are never tested with barovariations and go in blood with sudden doses.
Organize your life to do what you wanted (sex) and needed (reading FCOM ) chosed (fly) with adequate rest and stimulation.
Our school life didn't taught us that important aim to success.