I was in a bad car accident 2 years ago and was prescribed oxy contin 80mg. It was too hard to get off so I went on methadone. I started at 5ml 50mg, and went down 5mg every week sometimes 2 weeks, and once I got to 1ml I dropped down just 1mg every 2 weeks until I was off. I never had any issues and I'm being totally honest, but I wasn't dabbing with Oxys at all once I was going down. If you're not using anything while dropping the dose, you'll be fine, but obviously if you're using whatever while trying to drop your methadone dose then you will obviously have issues.