Do not take dandelion if you are taking a blood thinner, such as warfarin. You should also avoid dandelion if you have gallbladder issues, have diabetes or are taking medication to control blood sugar levels, or are taking a diuretic. If you are allergic to pollen, you may also be allergic to dandelion, so do not take it.
Dandelion may interact with other medicines, even though it is a natural herb. Dandelion interacts with medicines that treat diabetes or control blood sugar levels.
These drugs include insulin, glipizide, glyburide, metformin, acarbose, and tolbutamide. Diuretics, or water pills also have a negative effect on dandelion, so do not take these while on the dandelion.