Zyncet Allergy Tabs 10Mg belongs to a group of medicines called antihistamines. It treats various allergic conditions such as hay fever, conjunctivitis and some skin reactions. Also, it relieves watery eyes, runny nose, sneezing, and itching may cause some common side effects such as sleepiness, diarrhoea, nausea, dry mouth, dizziness, headache, etc. Consult your doctor if these symptoms stay for a long time or if they become severe.