DayQuil should be taken every 4 hours, but do not exceed 4 doses within 24 hours. For adults and children 12 years and older, the typical dose is 30 mL (liquid) or 2 LiquiCaps every 4 hours. Children 6 to under 12 years old should take half that dose (15 mL liquid), and children under 6 years should consult a doctor before use. Exceeding the recommended dose can lead to adverse effects such as liver damage.