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What Are the Side Effects of Epidiolex?

Epidiolex is the brand name of prescription medication manufactured by GW Pharma. Epidiolex is approved by the Food and Drug Administration (FDA) to treat two specific types of epilepsy to reduce seizure frequencies: Lennox-Gastaut syndrome and Dravet syndrome. These are uncommon, but severe conditions typically occur in infancy or early childhood.

Epidiolex contains cannabidiol (CBD) as the active ingredient. The product comes as a liquid solution that is taken orally. Epidiolex is recommended for use in adults and children aged two years and older.  

Is It Effective to Use?  

Epidiolex has decreased the number of seizures in people taking the drug in clinical trials. Many of the patients take Epidiolex in conjunction with at least two other epilepsy medications during these trials. The studies revealed:  

  • Individuals who have Dravet syndrome took Epidiolex and had 28% lesser seizures than those not taking it.  
  • Individuals with Lennox-Gastaut syndrome took Epidiolex and experienced 20% to 25% fewer seizures than those who did not use CBD.  

FDA Approved  

Epidiolex is an FDA approved product. This approval was in June 2018 and is the first drug approved to treat Dravet syndrome. It is also the first pure CBD-based medication to be approved by the FDA.  

Side Effects  

Epidiolex can cause moderate to severe side effects when taken at very high doses, > 10 mg CBD per Kg body weight. The list below shows some of the main side effects, which can occur when taking Epidiolex. Not all potential side effects are included in this article.  

More Common Side Effects  

  • Drowsiness  
  • Fatigue  
  • Skin rash  
  • Loss of appetite  
  • Malaise  
  • Diarrhea  
  • Insomnia  
  • Weakness  
  • Fungal and viral infections  

Most of these side effects may go away within a few days or weeks, depending on the person’s health condition. If they are more severe or do not go away, it is highly suggested to consult a doctor.  

Severe Side Effects  

The severe side effects caused by Epidiolex are not typical, but they can occur. When you have severe side effects, call the doctor right away. If your symptoms sound life-threatening or you think you have a medical emergency, call 911.  

The following are the details of the severe side effects of Epidiolex.  

  • Sedation (sleepiness, loss of coordination, and trouble thinking clearly)  
  • Liver problems  
  • Severe allergic reaction  
  • Suicidal thoughts or behavior  


The dosage of Epidiolex depends on several factors, such as:  

  • How severe your child’s health problem is; and whether it can be treated with Epidiolex or not  
  • The health of your child’s liver  
  • The weight of your child  
  • Whether your child is taking any other medications or not.  

Doctors usually begin with a low dosage and adjust their overtime to reach the dosage that works best. Also, they will ultimately prescribe the smallest dosage that provides the desired effect.