The aim of this study is to evaluate the effects and safety of a dietary supplement, Zataria multiflora Boiss (Shirazi's Thyme) in the treatment of non alcoholic fatty liver disease (NAFLD).

In a randomized double-blind placebo-controlled clinical trial Shirazi's Thyme is compared with placebo. Investigators select randomly 90 patients with NAFLD by inclusion criteria. Investigators measure anthropometric and laboratory parameters including fasting blood sugar, insulin, liver enzymes, lipid profile, and grade in sonography before intervention and 90 days later. Patients are divided into two equal groups. Intervention group in addition to diet and exercise recommendations receive capsules containing 700 mg of Shirazi thyme powder daily for 90 days. Placebo group in addition to the same recommendations for diet and exercise, receives placebo capsules twice daily.

Inclusion Criteria:

• Age: 20-65 years
• Body mass index: 18-35 kg/m2
• Serum ALT level: >45 U/Lit. in Males, >29 U/Lit. in Females
• Grade >=1 fatty liver in liver sonography

Exclusion Criteria:

• Pregnancy and Lactation
• Acute or chronic liver failure
• Acute or chronic renal failure
• Autoimmune or viral hepatitis
• Wilson's disease
• Diabetes mellitus
• Alcoholism
• Malignancy
• Hypothyroidism or hyperthyroidism
• Drug used in last three months: OCP, metformin, vitamin E, ursodeoxycholic acid, glucocorticoids, thiazolidenediones.
• History of allergic reactions to Thyme