Simethicone

What it is

Simethicone is a silicone-based antifoaming agent used for bloating and trapped gas. It is not absorbed from the gut; it works physically, lowering the surface tension of gas bubbles in stomach and intestinal contents so that small bubbles merge into larger ones that pass more easily. It has no effect on how much gas is produced, only on how it behaves.

A usual adult range, not a national label — the dose and the timing differ by country and by product.

Used for

• Bloating

Approved uses differ by country — some of these may be off-label or unapproved where you live.

What to know while taking it

It is taken with food, since that is when swallowed air and fermentation gas build up, and it acts locally in the gut rather than through the bloodstream. Because it is not absorbed, it does not deplete nutrients and does not shift laboratory values, and interactions with other medicines are not expected. It relieves a symptom; bloating driven by diet, constipation or an underlying gut condition will return once the effect wears off.

When to see a doctor

Bloating that comes with weight loss, blood in the stool, persistent vomiting, fever or severe abdominal pain is not something an antifoaming agent addresses, and warrants seeing a doctor. The same applies if bloating keeps coming back over weeks despite treatment.