Gascon (Simethicone)
An over-the-counter medication used to relieve mild to moderate discomfort caused by trapped gas and abdominal bloating.
Last Updated: 10 Sep 2026
What is Gascon?
Gascon is an over-the-counter anti-flatulent medication widely used to relieve painful pressure, bloating, and discomfort caused by excessive trapped gas in the digestive tract. It is frequently utilized for daily symptomatic relief and as a clinical preparation for diagnostic abdominal procedures like endoscopies.
Belonging to a class of surface-active agents, the active ingredient simethicone acts as a physiological surfactant with anti-foaming properties. It is not absorbed into the bloodstream, passing through the gut unchanged while altering the surface tension of trapped gas bubbles, causing them to coalesce and pass more easily.
| Property | Details |
|---|---|
| Medicine Name | Gascon |
| Also Known As | Simethicone, dimethylpolysiloxane |
| What It Does | Relieves abdominal bloating, trapped wind, and flatulence. |
| Active Ingredient | Simethicone |
| How It Works | Alters surface tension of gas bubbles, causing them to merge and pass easily. |
| How to Take It | Taken orally |
| Forms Available | Chewable tablets, liquid drops |
| Typical Dosage | Adults: 40mg to 125mg taken four times daily after meals. |
| Suitable For | Adults, children, and infants |
| Not Suitable For | People allergic to simethicone or those with suspected intestinal obstruction. |
Generic Names:
- Simethicone: The universally recognized generic name for this anti-foaming agent.
- Dimethylpolysiloxane: A chemical name frequently used in scientific literature and certain regional markets.
Global Brand Names:
Simethicone is sold under various brand names globally and across Hong Kong.
- Gascon (加斯克兒): The most prominent brand in Hong Kong, commonly available as 40mg or 80mg chewable tablets.
- De-Gas: A high-strength simethicone formulation frequently found in local pharmacies.
- Infacol: A globally recognized liquid formulation primarily used for infant colic, widely accessible in Hong Kong.
- Mylicon: A popular brand available in multiple pediatric formulations, recognized both internationally and locally.
These names all refer to the same medication. It's important to note that while the active ingredient is the same, different countries may have different regulations and available medication formulations.
What is Gascon used for?
Gascon is used to relieve:
- Flatulence and abdominal bloating
- Pressure and discomfort caused by trapped wind
- Post-operative gas pain following abdominal surgery
- Infantile colic (specific pediatric formulations)
How do you use Gascon?
Availability:
- Chewable tablets
- Liquid drops
Dosage Information:
- Adults and Children over 12 years: 40mg to 125mg taken four times daily after meals and at bedtime.
- Children (2–12 years): 40mg three to four times daily.
- Infants (under 2 years): Administered via specialized pediatric drops; closely follow specific product guidelines.
Suitability:
- Adults: Yes
- Elderly: Yes
- Children and Infants: Yes, using appropriate age-specific formulations
- Pregnant or breastfeeding women: Yes, but consult a healthcare provider first
Who cannot take Gascon?
Allergies and unsuitability:
- Rare, but possible allergic reactions to simethicone or formulation excipients.
Conditions where the drug should not be used:
- Known allergy to simethicone
- Suspected intestinal obstruction or perforation
Side effects are exceptionally rare because Gascon is physiologically inert and is not absorbed into the bloodstream. Common, mild reactions may include a slight increase in belching or mild diarrhea as the trapped gas is physically eliminated from the body.
Severe adverse reactions are highly uncommon but can involve allergic responses. Symptoms of a severe allergic reaction include skin rash, itching, swelling of the face or throat, severe dizziness, and difficulty breathing. If any of these severe allergic symptoms appear, the medication must be stopped immediately and medical help should be sought.
- Separate administration from thyroid medications (such as levothyroxine) by at least four hours to avoid reduced efficacy of the thyroid treatment.
- Do not exceed the recommended daily dosage to prevent minor gastrointestinal upset.
- Chew chewable tablets completely before swallowing to maximize surface area contact in the stomach.
- Stop use and check with a doctor if symptoms persist or worsen despite treatment.
Storage information:
- Store in a cool, dry place below 25°C to 30°C.
- Protect from direct sunlight and moisture.
- Do not freeze liquid formulations.
- Keep out of the reach of children.
Handling instructions:
- Chew tablets completely before swallowing; do not swallow whole.
- Use the specific measuring dropper provided with infant formulations to ensure accurate dosing.
Where is Gascon available in Hong Kong?
In Hong Kong, Gascon and similar simethicone products are classified as Over-the-Counter (OTC) medications. This means they can be sold freely without a prescription.
You can purchase these anti-flatulent medicines at general chain drug stores like Mannings and Watsons, registered community pharmacies, and various supermarkets and convenience stores across the city.
How fast does Gascon work?
Gascon generally begins to work within 15 to 30 minutes after oral intake. Chewing the tablets thoroughly helps the medication act more rapidly on gas bubbles in the stomach.
Should Gascon be taken with food?
It is best taken after meals and at bedtime. This timing helps manage the excessive gas produced during the natural digestion process.
Does Gascon cause constipation?
No, Gascon is not known to cause constipation. It may occasionally cause mild diarrhea or an increase in belching as the trapped gas is successfully passed.
Can pregnant women take Gascon?
Because the active ingredient is not absorbed into the bloodstream, it is generally considered safe during pregnancy. However, check with a healthcare provider before starting any new medication while pregnant.
Can I take Gascon with other medications?
Simethicone has very few interactions, but it can bind to thyroid medications like levothyroxine and decrease their absorption. Separate doses of these medications by at least four hours.
