What are the side effects of holy basil?

Holy basil is POSSIBLY SAFE when used by mouth for short periods of time, up to six weeks. It’s not known if long-term use is safe.

Special Precautions & Warnings:
Pregnancy and breast-feeding: Not enough is known about the use of holy basil during pregnancy and breast-feeding. Stay on the safe side and avoid use.

Surgery: Holy basil might slow blood clotting, so there is a concern that it could increase the risk of bleeding during and after surgery. Stop using holy basil at least 2 weeks before a scheduled surgery.