Diphenhydramine, or its brand name Benadryl, is a medication that adults and children commonly use to reduce allergic reactions as well as allergy symptoms.

The medication is a common part of over-the-counter cough and cold medicines, and some parents even report using it to cause drowsiness in their little one for a plane flight or car ride.

When your body experiences an allergic reaction, it produces substances known as histamines. These compounds are designed to identify allergenic substances and destroy them before they cause damage to the body. While allergies are intended to be your body’s way of protecting you, they can work against you sometimes too.

Benadryl is an antihistamine, which means it neutralizes the histamine particles in your body. In addition to this effect, Benadryl can be sedating. This means it causes you to feel sleepy. These effects are one reason why parents may try to give it to their babies. It can be a way to help them sleep on a plane ride or even if their child seems to be having difficulty getting to sleep.

Benadryl is also available as a cream to reduce itching and discomfort that could come with an insect bite or other nonspecific rash. This cream contains diphenhydramine HCL (the ingredient in oral Bendadryl) as well as zinc acetate to protect the skin.

While it can be tempting to use Benadryl for off-label uses such as helping your baby rest, using it on your little one is likely too risky unless your doctor advises it. This is because your child can have an adverse response to the medication. Side effects from Benadryl include:

  • dry mouth
  • rapid heart rate
  • stomach upset
  • vomiting

According to Wendy Sue Swanson, M.D., MBE, a doctor at Seattle Children’s Hospital, some children can have an opposite reaction to the medication. This includes unintended responses, such as heightened energy. If you were hoping to use it for its sleep-inducing effects, there’s a chance it could do exactly the opposite.

Also, Benadryl is largely untested on children younger than age 2. This means that there aren’t standard dosages to recommend. The effects on infants can vary. For some little ones, the medication may be especially sedating or sleep-inducing. This could be concerning as a parent.

According to the Benadryl Anti-Itch Cream labeling, the cream is not intended for use in children under age 2 unless as directed by a doctor.

Some parents may try to give Benadryl for colds. According to St. Louis Children’s Hospital, Benadryl isn’t advised for colds for those under age 4 because it’s not proven to help reduce cold symptoms.

Circumstances are different for every infant. If your child’s doctor does recommend using Benadryl for travel or otherwise on your baby, you may want to try a trial run at home first to see how your child responds. This way, if your child does have an allergic reaction or unexpected response, you can quickly seek emergency medical treatment. That’s much better than needing help thousands of feet in the air.

Remember also that there are different formulations for Benadryl, including children’s formulations and adult ones. Always discuss with your child’s pediatrician the formulation you are considering using as well as the delivery route. For example, you should use the dropper that comes with the children’s Benadryl packaging instead of another measuring method or spoon to ensure the most accurate measurement.

If your infant has a cold, contact their doctor about possible treatments or if your child should be seen. Often, the risks of giving your infant cold medicines or using Benadryl for the cold outweigh the benefits and aren’t recommended. Steps you can take instead include:

  • using saline (salt) water spray to loosen and thin mucus
  • using bulb suction, bulb syringes, or nasal aspirators to remove thick mucus from your baby’s nose or mouth
  • using a cool mist humidifier in your baby’s room as a means to thin mucus, making it easier for your baby to cough it out
  • asking your doctor about possibly giving your child acetaminophen (Tylenol) for fever
  • encouraging your child to drink plenty of liquids, like formula or breast milk in very young infants

However, if your child has symptoms of a more serious illness, it’s important to seek immediate medical care. This includes if your child is struggling to breathe, has seizure-like activity, or their lips appear to be turning blue.

Benadryl is better left for when your child is older and may require it for an allergic reaction or as part of a cold medicine treatment. If you do suspect your child is having an allergic reaction or a cold, contact your child’s doctor for instructions.

The medicine shouldn’t be used off-label for things like causing an infant to sleep because a child may have side effects from the medicine.