Boil 1 tsp. of shaved pieces of barberry bark or powdered bark in 1 cup of water for about 15 minutes.
Drink 1 cup of the boiled bark water before each meal, three times daily, to help with gastrointestinal problems.
Gargle with 1 cup of the boiled bark water three times daily for sore throat or oral ulcers.
Ingest a tincture of barberry bark three times a day. Use a dose of 1/2 to 1 1/2 tsp. each time.
Ingest barberry bark tablets of 250 to 500 milligrams three times each day.
Use an ointment that has a 10 percent barberry extract to treat skin irritations. Apply three times a day.