My wife and I are planning on a holiday to China and we're on Methadone for chronic pain which we will need during our trip. We have prescriptions and letters from our doctor. I tried searching China customs regulations on bringing medications into China (They emphasized on bringing letters from GP for any medications but they said controlled substances are strictly prohibited. Methadone is a controlled substance in Australia but it is a prescription medication too)Can we bring these medications into China and not have any hassle?