Checked against UN INCB controlled substance lists and Japan rules.
Japan treats pseudoephedrine as a stimulant precursor. Cold medicines containing it, including Sudafed and some Vicks products, cannot be brought in even with a prescription.
Leave it at home. Ask your doctor about an alternative that is legal at your destination, and carry a doctor's letter describing your condition.
Official source for Japan: www.mhlw.go.jp
Check Sudafed in 21 countriesNot legal or medical advice. Rules change and depend on dose, form and quantity. Always confirm with the Japan embassy or health authority before you fly. We never tell you a medicine is "safe" to carry.