I had no idea that mistletoe was in anyway edible so, when I saw mistletoe tea for sale in the local health food shop that I drop into most (Elf Foods), I couldn’t resist getting a packet to try. Health may sell things that are sometimes of limited benefit but they are unlikely to be actively harmful, certainly with reasonable levels of usage.
The ingredients are just dried mistletoe leaves (so, more accurately, this is a tisane rather than a true tea) and the taste puts me in mind of a more mellow chamomile. Pleasant and I would buy again, assuming I do get through the packet at a reasonable rate.
I did do a little further research and mistletoe is regarded as mildly poisonous in its raw form although a skilled herbalist may use it for medicinal purposes. However, the drying of the leaves is thought to reduce the toxicity further. It isn’t a tea I’d want to be drinking pots of but I might pop to the kitchen in the moment and see if, like chamomile, you can get a decent second cup out of the one bag.