Benadryl, also known by its generic name diphenhydramine, is an antihistamine medication used to treat allergy symptoms. It can be a helpful tool for babies experiencing allergic reactions, but administering the correct dosage is crucial for their safety. Moreover, how often can you give your child Benadryl—and what’s the recommended Children’s Benadryl dosage by weight? Read on to learn what you need to know about using this over-the-counter drug. Use these benadryl dosage guides for infants and children younger than 12 years old. Find BENADRYL® dosage information for adults, children, and toddlers and learn how much you and your family should take with our allergy medicine product-dosing guide. Shop baby benadryl at Walgreens. Find baby benadryl coupons and weekly deals. Pickup & Same Day Delivery available on most store items. Shop benadryl baby at Walgreens. Find benadryl baby coupons and weekly deals. Pickup & Same Day Delivery available on most store items. Benadryl is generally not safe to give to babies or infants under 2 years old at home. Sometimes, people can safely give infants aged 2 to 5 small doses of Benadryl, but only when a doctor. Giving your child Benadryl? Find the recommended amount of Benadryl to give your child based on age and weight using the St. Louis Children's Hospital Benadryl dosage chart. Is there an infant version of Benadryl? Benadryl is not recommended for infants or children under 2 years of age, as it can cause serious or even fatal side effects. Benadryl isn't suitable for children under 2 years. Those aged 2 to 5 years can only use it as directed by a doctor. Read about side effects and alternatives.