Simethicone is an anti-foaming agent that decreases the surface tension of gas bubbles, causing them to combine into larger bubbles in the stomach that can be passed more easily. Simethicone does not reduce or prevent the formation of gas in the digestive tract, rather, it increases the rate at which it exits the body.^[1] However, simethicone can relieve pain caused by gas in the intestines by decreasing foaming which then allows for passing of flatus. Simethicone is not absorbed by the body into the bloodstream, and is therefore considered relatively safe. National Institutes of Health (NIH)^[2] reports there are usually no side effects when Simethicone is taken as directed. Although simethicone has also been promoted as a treatment for colic, randomised controlled trials have not demonstrated efficacy for such use.^[3][4]

Simethicone solutions of differing concentration also have industrial applications for reducing foaming in certain chemical processes.

The use of simethicone can help reduce visual obstructions caused by intestinal gas during ultrasounds of the abdomen, although it has no effect on extraluminal gas outside the colon.