Diphenhydramine (Benadryl) is an over-the-counter (OTC) oral medication that's commonly used to treat allergies, common cold symptoms, and itching. Because it makes most people very sleepy, it can also be used as an occasional sleep aid.
Diphenhydramine (Benadryl) is an antihistamine. It blocks the action of histamine, a natural chemical in your body that causes sneezing, itching, and runny nose.
By stopping histamine from working, diphenhydramine (Benadryl) can help relieve symptoms from allergies or the common cold. And since it tends to cause a lot of drowsiness while it's working, it can also be used to help with trouble sleeping.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
No. You shouldn't drink alcohol with diphenhydramine (Benadryl) because it can raise your risk of side effects from the medication. Combining alcohol and diphenhydramine (Benadryl) can result in severe drowsiness, dizziness, and confusion. So it's best to avoid drinking alcohol while you're taking diphenhydramine (Benadryl).
Yes. Diphenhydramine (Benadryl) is the main ingredient in several OTC sleep aids. Keep in mind, these products should only be used by people that are 12 years of age and older. And only occasionally to help with sleep. Sleep aids containing diphenhydramine (Benadryl) haven't been proven to be safe and effective as a treatment for diagnosed insomnia. If you're still having trouble sleeping after using diphenhydramine for 2 weeks, talk to your provider. You might have another problem that's causing sleeplessness that your provider can check out.
No. Diphenhydramine (Benadryl) should only be used for short-term problems with allergy, cold symptoms, or sleep. So you should stop using it once your cold or allergy symptoms go away. And if you're using the medication for sleep, don't take it for more than 2 weeks at a time. When used long term, it's possible that diphenhydramine (Benadryl) raises your risk for problems with memory and confusion, especially in older adults. Talk to your provider or pharmacist about other options if diphenhydramine (Benadryl) isn't giving you the relief that you need.
It can be, if diphenhydramine (Benadryl) is taken the right way. There are plenty of allergy and cold products labeled for children. They come in dosage forms that are easier for children even as young as 6 to take, like liquid and chewable tablets. But, never use diphenhydramine (Benadryl) for sleep in children younger than 12 years old because of the risk of serious side effects. Discuss with your provider or pharmacist if you have questions about using diphenhydramine (Benadryl) in children.
Yes. Diphenhydramine (Benadryl) is considered safe to take during pregnancy. But it's always best to talk to your provider before you take any medications, including OTC products, while pregnant.
Diphenhydramine (Benadryl) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Many OTC products contain diphenhydramine, the main ingredient in diphenhydramine (Benadryl). It's not safe to use more than one medication containing diphenhydramine at the same time, including products used on the skin. If you take too much diphenhydramine (Benadryl) you might experience dry eyes or mouth, fast heart rate, trouble urinating, fever, and constipation. Overdosing on diphenhydramine (Benadryl) can also lead to more serious side effects like severe confusion, seizures, low blood pressure, involuntary muscle spasms, hallucinations (seeing things that aren't there), and heart rhythm problems.
In fact, the FDA released a warning to avoid high doses of diphenhydramine. To prevent accidentally overdosing with diphenhydramine (Benadryl), read package labels carefully to make sure you take the right dose. If you're not sure if a product contains diphenhydramine, ask your provider or pharmacist.
Diphenhydramine (Benadryl) causes severe drowsiness for many people who take it. This can affect your ability to focus, think, and react. This side effect can be especially dangerous for older adults (ages 65 years and older), because it raises the risk of falls. It's also more likely to cause drowsiness the next day in older adults. Sleepiness from diphenhydramine (Benadryl) can be made more intense if you drink alcohol while taking this medication, or take other medications that cause drowsiness (e.g., opioids, benzodiazepines, sleep medications). Avoid activities that require you to be alert, such as driving a car or operating machinery, until you know how this medication affects you.
Talk to your provider before using diphenhydramine (Benadryl) if you have glaucoma, an enlarged prostate, problems with breathing (e.g., emphysema), or kidney problems. Taking diphenhydramine (Benadryl) can make these problems worse and could lead to serious side effects.
Diphenhydramine (Benadryl) comes in many different dosage forms (e.g., tablets, capsules, liquid). Be sure to check the package label to make sure you're taking the correct dose. Ask your provider or pharmacist if you have questions about dosing.
Allergies and common cold symptoms:
Trouble sleeping: