Mylicon works by lowering the surface tension of gas bubbles trapped in your baby’s digestive tract. Its active ingredient, simethicone, is a silicone-based compound that acts as a surfactant, causing small, scattered gas bubbles to merge into larger ones. Those larger bubbles are much easier for the body to expel naturally through burping or passing gas. The medication itself is never absorbed into the bloodstream. It stays entirely within the digestive tract and passes through unchanged.
What Happens Inside the Digestive Tract
When an infant swallows air during feeding or crying, tiny gas bubbles can become trapped along the walls of the stomach and intestines. These small bubbles create pressure and stretching that can cause visible discomfort: a tight belly, squirming, and fussiness. Simethicone works on a purely physical level. It breaks the film that holds each small bubble intact, allowing dozens of tiny bubbles to combine into fewer, larger ones. This process is called coalescence.
Once the gas has consolidated, the body can move it along much more efficiently. Larger bubbles travel through the digestive tract and exit as a burp or as flatulence. Simethicone doesn’t reduce the total amount of gas in your baby’s system. It reorganizes it so the body can get rid of it faster.
Why It’s Considered Very Safe
Because simethicone is non-systemic, it never enters the bloodstream. It works only on the surface of gas bubbles inside the gut, then passes through the body without being digested or absorbed. This is a key reason it has been used in infants for decades with an extremely low risk of side effects. There are no significant reported adverse reactions tied to the compound itself.
One interaction worth knowing about: simethicone can interfere with thyroid medication (levothyroxine) by binding to it in the gut and blocking its absorption. If your child takes thyroid medication, the two should be given at least four hours apart.
Dosing for Infants and Young Children
Mylicon Infant Gas Relief drops use a straightforward dosing guide based on age and weight. Infants under 2 years old (weighing under 24 pounds) get 0.3 mL per dose. Children over 2 years old (over 24 pounds) get 0.6 mL per dose. The drops can be given up to 12 times in a 24-hour period, typically administered with or after feedings. You can mix the drops into a bottle of formula or breast milk, or place them directly on the tongue using the included dropper.
What the Evidence Says About Effectiveness
Here’s where things get more nuanced. Mylicon is widely used and trusted by parents, but the clinical evidence for its effectiveness against infant colic is surprisingly weak. A large systematic review published in BMJ Open examined multiple studies and reviews on simethicone for colic and found that the data did not support its use. Five separate reviews concluded that simethicone either made no difference in crying time or, in some cases, was associated with worsening symptoms. The overall quality of the studies was rated low to moderate.
One older clinical trial did report that colic symptoms improved or resolved in 78% of infants after one day of treatment and 86% after seven days. However, colic also tends to improve on its own over time, and without a strong placebo comparison, it’s hard to separate the drug’s effect from the natural course of the condition. Three out of four clinical guidelines reviewed in the BMJ Open analysis recommended against using simethicone for colic, favoring continued breastfeeding and physical contact instead.
This doesn’t mean Mylicon is useless. Its mechanism for consolidating gas bubbles is real and well understood. For a baby whose discomfort genuinely stems from trapped gas rather than the broader, less understood phenomenon of colic, it may offer relief. The disconnect in the research likely reflects the fact that “colic” is a catch-all diagnosis, and gas is only one of several possible contributors to prolonged infant crying. When gas is the actual problem, helping it pass faster makes logical sense. When something else is driving the fussiness, a gas remedy won’t address the root cause.
Gas Pain vs. Colic
Gas discomfort and colic overlap in symptoms but aren’t the same thing. A baby with gas pain typically pulls their legs toward their belly, has a visibly distended stomach, and feels better after passing gas or having a bowel movement. The episodes are tied to feeding and tend to be shorter. Colic, by contrast, is defined as crying for more than three hours a day, more than three days a week, for more than three weeks, often without an identifiable physical cause.
If your baby’s fussiness clearly correlates with feeding and resolves after burping or passing gas, Mylicon targets exactly that mechanism. If the crying is prolonged, inconsolable, and doesn’t follow a clear pattern tied to digestion, the issue is more likely colic, and the evidence suggests simethicone is unlikely to help.