Overdose Effects

• If a patient takes more skullcap than the herbal practitioner recommends, he could suffer from giddiness, feel confused and go into a stuporous state where his responses to stimuli are much slower than usual. He may also twitch his muscles, become dizzy or feel very sleepy.
  
  Seizures are another possibility if a patient takes too much of the herb, as is an irregular pulse.
  
  

Liver Damage

• Skullcap is linked to cases of liver damage, although this may be due to contamination or replacement by another herb, germander, also known as pink scullcap. Symptoms of liver damage are jaundice, where the eyes and skin become yellow, and pain in the top right of the abdomen.
  
  

Drug Interactions

• The relaxant effect of both types of skullcap can make the sedation properties of certain drugs more powerful. The drugs that the herb can affect include barbiturates and antidepressants such as Valium or Xanax. A person who takes anticonvulsants, or someone who takes medication to treat insomnia should consult a doctor prior to using skullcap. Sedation herbs such as valerian or catnip may become more powerful if the patient takes skullcap at the same time. The adverse effects of alcohol are also made worse by skullcap.
  
  

Illness Interactions

• Chinese skullcap has an effect on blood sugar levels. A person with diabetes should not take skullcap because it may cause his blood sugar to drop, leading to hypoglycemia. The herb can increase the potency of diabetes medication. A patient with liver problems should not take skullcap as it increases the potential for liver damage. Patients suffering from spleen or stomach problems should also avoid skullcap.
  
  

Lack of Research

• Scientists have not performed enough research on either Chinese skullcap or American skullcap to assess all the potential risks of the herb. Children and pregnant and breastfeeding women are advised to avoid using the herb because as of May 2011, the full risks are unknown.