I'm just wondering, if you take vyvanse (lisdexamfetamine) for adhd and smoke weed can it harm you?

Weed vs. Vyvanse (lisdexamfetamine): Vyvanse (lisdexamfetamine) is used to treat symptoms of adhd, inattention, distractibility, easy fatiguabilty and poor concentration skills. Marijuana may reduce your alertness, ability to initiate, and memory. Therefore the benefits of vyvanse (lisdexamfetamine) may be counteracted by marijuana. Mj has been shown to produce permanent cognitive ability if used frequently and is worse for your lungs than cigarettes.

Mixing drugs is BAD.: Mixing street drugs with pharmaceuticals is not a good idea, ever. You don't know and nobody else really knows if these can harm you because you don't know what is really in the street drug.