Multicentric clinical trials of the efficacy of gugulipid conducted at Bombay, Bangalore, Delhi, Jaipur, Lucknow, Nagpur and Varanasi have been reported. Two hundred and five patients completed 12 week open trial with gugulipid in a dose of 500 mg tds after 8 week diet and placebo therapy. One patient showed gastrointestinal symptoms which did not necessitate withdrawal of the drug. A significant lowering of serum cholesterol (av. 23.6%) and serum triglycerides (av. 22.6%) was observed in 70-80% patients Double-blind, crossover study was completed in 125 patients with gugulipid therapy and in 108 patients with clofibrate therapy. Two patients had flu-like syndrome with clofibrate and opted out from the study. With gugulipid the average fall in serum cholesterol and triglycerides was 11 and 16.8% respectively and with clofibrate 10 and 21.6% respectively. The lipid lowering effect of both drugs became evident 3-4 week after starting the drug and had no relationship with age, sex, and concomitant drug intake. Hypercholesterolaemic patients responded better to gugulipid therapy than hypertriglyceridaemic patients who responded better to clofibrate therapy. In mixed hyperlipidaemic patients response to both drugs was comparable. HDL-cholesterol was increased in 60% cases who responded to gugulipid therapy. Clofibrate had no effect on HDL-cholesterol. A significant decrease in LDL-cholesterol was observed in the responder group to both drugs.