Can I take my medication with me to Indonesia?

Of course you can take your medication to Indonesia.

However, it is necessary to make arrangements in advance to prevent problems at customs.

Make sure you have an European Medical Passport or a medical statement (in English) from your doctor before you leave. Your doctor can arrange this for you. In the Medical passport or statement your doctor will indicate which medication you are using.
Take your medication (sufficient for your entire trip) with you in the original packaging.

There are special rules for medicines which fall within the Opium Act (such as certain sleeping medication, some heavy painkillers, but also, for example, ritalin). You need a special (legalized) statement to be able to take this medication with you. If you live in the Netherlands, you can request this statement from the CAK. This statement is valid for 1 year and must be requested at least 4 weeks before departure. If you live in a country other than the Netherlands, ask the nearest Indonesian embassy for advice.
Make sure that you do not take more of the medication (which falls within the Opium Act) with you, than you need for your journey according to your doctor’s prescription.

Check the website of the nearest Indonesian embassy for the most current regulations.