* Pregnancy and breast -feeding: Not enough is known about the use of forsythia during pregnancy and breast-feeding. Stay on the safe side and avoid use.
*Surgery: Because forsythia might slow blood clotting, there is a concern that it might cause extra bleeding during and after surgery. Stop taking forsythia at least two weeks before a scheduled surgery.
* Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with Forsythia.
==The benefits of Forsythia are==
* Inflammation of small air passages in the lung (bronchiolitis). Developing research suggests that children with bronchiolitis due to a particular infection (respiratory syncytial virus infection) get over their symptoms faster when given a combination of forsythia, honeysuckle, and Baikal skullcap intravenously (by IV).