Shelf life of Datura??

For those who dabble, any ideas on just how long it's worth hanging on to dried material before it loses potency?
Have some left from last year's growth and just repotted so want to give her time to settle into her new home before I start borrowing leaves. (I'll add a pic when the sun comes up )

 

Those alkaloids dont degrade very much, at least I dont believe they do. Ive some from years ago. If I see some new plants around, Ill gather some new. Havent used it in a while.

 

The more I read about it's historic uses and after over a decade of intermittent, moderate dabbling I have to wonder if the overcautionary tales of terror we hear aren't in some part fuelled by the pharmacological industry much in the way Mary Jane got twisted.
I certainly have noticed at least a somewhat comparable impact to the Ventolin inhaler I use.