Jiaogulan is a relatively new herb in the North American natural health market. You can ask for it at your local health food store, but not many stores carry it, and the quality is questionable.
You can also check with a Chinese herbalist in your area.
For convenience I recommend this reliable source that ships directly, you can either buy from their website or if you prefer, they sell the same products on Amazon:
Jagulana Herbal Products
“The jiaogulan experts since 1995.”
Best of health,