Metabolically activated steviol, the aglycone of stevioside, is mutagenic.
Pezzuto JM, Compadre CM, Swanson SM, Nanayakkara D, Kinghorn AD. Metabolically activated steviol, the aglycone of stevioside, is mutagenic. Proc Natl Acad Sci U S A. 1985 Apr; 82(8):2478-82.