The present study aimed at investigating the cholesterol-lowering and side effects of garlic enteric coated tablets in comparison with placebo tablets. The study is a randomized double-blinded crossover design involving 116 volunteers. However, 16 of them did not complete the study. The remaining 100 volunteers were divided into two groups: 45 were in the trial group and the remaining 55 in the control group. The volunteers in the trial group were asked to take garlic tablets in the first three months, placebo in the second three months and discontinue all tablets in the last three months, while the volunteers in the control group started with three months of placebo followed by three months of garlic tablets and ended up with three months of tablets discontinuity. The results showed that there were no significant differences in the total serum cholesterol levels between the two groups at the end of three months or six months of the study. Side effects included headache, itching and complaints of garlic smell. No serious side effects relating to liver, kidney functions or hematologic side effects were detected