Hello! I’m not on Vyvanse, I’m on Concerta XL (or xaggitin when my pharmacy can’t get it) which is the other adhd stimulant drug. I can’t speak for other meds, but my general stimulant experience is that the changes generally happen instantly. Unlike other medication, adhd meds arent accumulative so they work immediately. I felt immediately better like the first day i took them, and then gradually increased my dosage through titration. That being said it might take a while for you to realise the changes - I found keeping a journal made me realise the extent of the changes. Also, without wanting to be a narc, I’d be really careful with self-medication on stimulants and increasing dosages without titration monitoring. My housemate was going to try some of mine, as she’s also sure she has adhd, but turns out she has a heart condition and it could have literally killed her. Make sure that you’re taking your blood pressure and heart rate frequently at least and stop if you’re losing lots of weight. Adhd meds were life changing for me, but for some of my friends it made their anxiety and ocd symptoms worse, so keep checking in with yourself.