Not Medical Advice: Most people that have taken Vyvanse are aware of the fact that it can eliminate your appetite. Some people may have to force themselves to eat while on this drug because they simply don’t get the urge to eat. This is a common problem, especially among individuals taking high doses.
For some people Vyvanse causes weight loss, although like Adderall weight loss, Vyvanse weight loss isn’t really caused by the drug; it is caused by the decreased appetite side effect.
Vyvanse can make it so you don’t feel hungry, and therefore do not eat as often, or as much as you would normally. Not eating so much is what makes you lose weight, not taking Vyvanse. In other words, if you eat just as much as you normally would while taking Vyvanse, you will not lose weight.
See MentalHealthDaily.com's Vyvanse & Weight Loss: A Common Experience to learn more about how Vyvanse and appetite loss are related.
For information about specific side effects of taking Vyvanse, go to www.drugs.com.