Best Remedy: Adjust to Your New Daily Cycle as Quick as Possible
A good way to cure a jet lag is to get attuned to your new daily rhythm as quickly as possible. Follow the new schedule and do not look back. Just pretend you have been in that place already for a long time. So do not go earlier to bed as you normally would and especially do not oversleep. This can be hard the first night but the next nights will be so much easier. So ideally you will only have to endure a jet lag the first day (depending on your physical condition of course).
If you fly west-east you will arrive in a later time zone. It can be difficult to get to sleep because for your body clock it is still morning/afternoon while the local time is at night. One way to overcome this is to not sleep on the plane so that you feel tired enough to fall asleep. Sometimes a little alcohol after you have arrived (i.e. one glass of wine maximum) can work very well to put you into the sleepy zone also.
In case you fly east-west you will arrive in an earlier time zone. If you arrive at night that can be perfect as you can go to bed quickly. When you did not sleep well on the plane you will feel tired but it is important that you stretch a couple of hours until your normal bedtime. You can differentiate one hour when that is more convenient.
Now, there are also medical supplicants to help you go to sleep easily or that even can make your body clock more quickly. We do not recommend these, for the main reason that they are unnatural shortcuts for a non-critical physical condition (if you are a healthy person). These supplements will likely stretch out the problem of a jet lag over the long run. Of course, a little alcohol to sleep or a little caffeine to wake up is perfectly fine to use for overcoming a jet lag, if your medical condition allows it.
In any case, the bottom line to overcome a jet lag is: do not engage in crazy solutions or long drawn sleeping adjustments. Cold turkey is the way to go. Get accustomed to your new daily routine as quick as possible and you will be fit and proper in no time.