Is there a prescription diet pill that is safe to take with methadone? and won't make me feel like i'm speed balling or something?

Yes.: There are a few medications that may help people lose weight by reducing their absorption of calories, e.g., orlistat; or suppressing appetite;, e.g. Meridia. However, neither of these shold be attempted without medial supervision, particularly in the presence of use of methadone.

See below : Low dose Phentermine may help without making you speedy (15 mg) but you have to see. It will need to be combined with topiramate or zonisamide. It is less likely to work on persons on xanax (alprazolam). You may be eating to sooth yourself from interdose sedative withdrawal.