How long before gastroscopy (and h pylori evaluation) would you recommend to stop taking herbal supplements such as dgl licorice?

Supplements.: You definitely need to stop them the night before. However, you might want to consider stopping them now. If you are trying to make a diagnosis of the cause of your symptoms, the fewer complicating factors, such as the effect of any supplements or interactions that they may be having with your medications, the better. If your G.I. agrees, you could restart them after the EGD. Good luck.