No relevant or persistent changes in the extensive clinical serum tests have been found so far; also no influence on vital parameters have been reported after using EGCG. Only minimal and transient changes of the blood pressure, echocardiography, liver function tests and serum lipids have been reported. In a study of Chow et al. healthy subjects were given 800 mg EGCG or Polyphenon E (a mixture of several green tea extracts with a 50-75%share of EGCG) once daily or 400 mg twice daily versus placebo over a period of 4 weeks. Only mild side effects occurred in several subjects (flatulence, abdominal pain, nausea, headache, dizziness and muscle pain) that were not occurring more often than under placebo.