Side effects: Herbalists report side effects of dizziness, confusion, and irregular heart rhythm at large doses.14 Other sources report seizures at high doses.3
Adverse events: Four cases of hepatotoxicity have surfaced, though the causal pathway is unclear. The products in question reportedly contained a combination of skullcap and valerian.14The hepatotoxic effects may also have been due to contamination of the skullcap with germander, also known as ‘pink scullcap’ (Teucrium canadense) (other Teucrium species are known to cause liver damage).13 One case of pneumonitis with the related species Scutellaria baiclensis, has been reported in the literature.15

Precautions/contraindications: safety in pregnant and nursing mothers and in children has not been studied. Until it is clear that skullcap has no hepatotoxic properties, health practitioners should be cautious in recommending it for patients with liver disorders.3