Two studies into the safety of mistletoe have been published:

Clinical safety of combined therapy of immune checkpoint inhibitors and Viscum album L. therapy in patients with advanced or metastatic cancer : Thronicke et al 2017
This study looks at adverse reactions in patients receiving immune therapy and those receiving immune therapy alongside mistletoe therapy. It suggests that there is no significant difference in adverse reactions in the two groups.

Immune-related and adverse drug reactions to low versus high initial doses of Viscum album L. in cancer patients : Schad et al 2017
This study explores adverse reactions to low and high dose mistletoe therapy during the introduction phase. It indicates that although high dose introduction is associated with more adverse reactions, nearly all such reactions were expected , of mild to moderate intensity and most were desired reactions.

To read more about either study, visit our Research page.