Special Precautions and Warnings When taken by mouth: Ashwagandha is possibly safe when used for up to 3 months. The long-term safety of ashwagandha is not known. Large doses of ashwagandha might cause stomach upset, diarrhea, and vomiting. Rarely, liver problems, including severe liver failure and a need for liver transplantation, might occur.

In some individuals, ashwagandha preparations may cause drowsiness, stomach upset, diarrhea, and vomiting. Although it is rare, there have been a number of cases that link liver injury to ashwagandha supplements. Ashwagandha should be avoided during pregnancy and should not be used while breastfeeding.

Talk to a doctor before using ashwagandha if you have any health conditions, including cancer, diabetes, thyroid problems, bleeding disorders, ulcers, lupus, multiple sclerosis, or rheumatoid arthritis. Ashwagandha might interfere with thyroid tests. Stop taking ashwagandha two weeks before surgery.

If you are pregnant or breastfeeding, you should avoid ashwagandha. Likewise, if you have hormone-sensitive prostate cancer, are about to have surgery, or have an autoimmune or thyroid disorder, do not take ashwagandha. If you’re taking other medications, talk to your doctor or pharmacist to make sure there are no conflicts.