A natural food supplement reduces anxiety in mice, according to a new Weizmann Institute of Science study. The plant-derived substance, beta-sitosterol, was found to produce this effect both on its own and in synergic combination with an antidepressant known under the brand name Prozac. If these findings, published today in Cell Reports Medicine, are confirmed in clinical trials, they could point the way toward the use of beta-sitosterol as a treatment for relieving anxiety in humans.