Ingredient

Tetrahydrozoline Hydrochloride

Tetrahydrozoline hydrochloride is an active ingredient in eye drops that relieves eye redness.

All medicines
37
Combination
37
Prescription medication
24
OTC medication
13

MFDS ingredient code M223237

What does it do?

Tetrahydrozoline hydrochloride acts as a sympathomimetic agent, primarily used in eye drops to reduce redness of the eyes. It works by constricting blood vessels to alleviate redness.

This ingredient relieves redness by constricting the blood vessels in the eyes, reducing blood flow. As the vessels narrow, the eyes become less red and appear visually clearer.

Approved uses differ by product. Check each product's information for its actual use.

Good to know

Unlike other decongestants, tetrahydrozoline hydrochloride has a relatively fast onset of action and immediate effects. However, caution is required as rebound hyperemia may occur with prolonged use.

Medicines containing this ingredient

Even with the same ingredient, strength, dosage form and how it is taken can differ.

Category
Dosage form
Strength
Category

37 total

View more

Even with the same ingredient, dosage and approved uses can differ by strength, dosage form and combined ingredients. Check each product's information before taking it.

Combined ingredients

Ingredients used together with this ingredient in combination products.

Questions about this ingredient

  • QIs it okay to use eye drops that relieve redness every day?

    Tetrahydrozoline hydrochloride is a component that constricts the blood vessels in the eyes, quickly reducing redness. However, prolonged use can result in rebound hyperemia, where redness may worsen, so caution is advised. If redness persists, rather than relying on eye drops, seek evaluation from an ophthalmologist.

    Answers 1 · 2026.09.14

For anything that needs medical judgment, consult a doctor or pharmacist.

SourceKorea Ministry of Food and Drug Safety (Drug Safety Korea)

This drug information is based on data provided by the Korea Ministry of Food and Drug Safety.
Consult a doctor or pharmacist for accurate dosage, administration, and usage instructions.