C
Clarity News Hub

What is the side effect of Benadryl?

Author

Daniel Moore

Published Jan 10, 2026

Drowsiness, dizziness, constipation, stomach upset, blurred vision, or dry mouth/nose/throat may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

What are the side effects of taking Benadryl every day?

What Are Side Effects of Benadryl?

  • drowsiness,
  • fatigue,
  • tiredness,
  • sleepiness,
  • dizziness,
  • disturbed coordination,
  • constipation,
  • dry mouth/nose/throat,

What should you not take with Benadryl?

Benadryl may interact with other types of medication, which can heighten the side effects.
...
Examples of medications that may interact with Benadryl include:

  • antidepressants.
  • stomach ulcer medicine.
  • cough and cold medicine.
  • other antihistamines.
  • diazepam (Valium)
  • sedatives.

Is it OK to take Benadryl every day?

Benadryl is recommended only as a short-term treatment for people with symptoms of allergies or other conditions that the drug treats. If you take Benadryl long term, you may develop long-term side effects of the medication.

What happens if you take Benadryl every night?

You should not take diphenhydramine every night. While it may be helpful during limited periods of insomnia, your body will build up a tolerance for the medication over time, and it will no longer have the desired effect. After 2 weeks of taking diphenhydramine, you may become dependent on it to fall asleep.

36 related questions found

What is the safest sleep aid?

Melatonin: Melatonin is considered one of the safest over-the-counter sleep aids, with few side effects. A prescription drug called ramelteon is designed to mimic the effects of melatonin. Like melatonin, it is not considered habit-forming and it does not affect balance.

How long do Benadryl side effects last?

Benadryl is quickly absorbed after oral administration and peak effects are reached within one hour. The effects of diphenhydramine last from four to six hours. Benadryl in the injectable form has a rapid onset of action. When used as a night-time sleeping aid, the usual dosage of Benadryl is 50mg at bedtime.

Will Benadryl raise your blood pressure?

Official Answer. Increased blood pressure is not a typical side effect of diphenhydramine, a first-generation antihistamine that lowers the effects of histamines in your body. However, in rare cases, the drug may cause hypotension, or decreased blood pressure.

Is Benadryl hard on your liver?

Despite widespread use over many decades, diphenhydramine has not been linked to liver test abnormalities or to clinically apparent liver injury. The reason for its safety may relate its short half-life and limited duration of use. Likelihood score: E (unlikely to be a cause of clinically apparent liver injury).

Can too much Benadryl cause problems?

09-24-2020 FDA Drug Safety Communication

The U.S. Food and Drug Administration (FDA) is warning that taking higher than recommended doses of the common over-the-counter (OTC) allergy medicine diphenhydramine (Benadryl) can lead to serious heart problems, seizures, coma, or even death.

What does Benadryl treat?

Benadryl is an over-the-counter antihistamine that's used to help relieve symptoms of hay fever, other allergies, and the common cold, as well as itchy skin caused by insect bites, hives, and other causes.

Is Benadryl good for sleep?

Although antihistamines like Benadryl will make you feel sleepy, they're not a great choice when it comes to treating insomnia. Not only can they affect your sleep quality, but they'll also become less effective very quickly, meaning you may not notice any benefits if you use them often.

How long can you take Benadryl for sleep?

Patients can become tolerant to the sedative effect within days of taking it repeatedly, and it is usually not recommended for more than three days in a row. Use of diphenhydramine as a sleep aid should be limited according to the American Academy of Sleep Medicine (AASM) guidelines.

How many Benadryl can I take?

Do not take more than 6 doses in 24 hours. Use only as directed. 2 to 4 chewable tablets (25 mg to 50 mg) every 4 to 6 hours or as directed by a doctor. 1 to 2 chewable tablets (12.5 mg to 25 mg) every 4 to 6 hours or as directed by a doctor.

Is Benadryl hard on your kidneys?

In general, anti-histamines do not cause kidney problems. Some, such as diphenhydramine (Benadryl) can cause retention of urine in your bladder. Others such as Claritin and Zyrtec are generally very safe.

How many days can you take Benadryl in a row?

Call your doctor if the condition you are treating with diphenhydramine does not improve, or if you have a fever with a headache, cough, or skin rash. Do not use diphenhydramine for longer than 2 weeks to treat sleep problems, or longer than 7 days to treat cold or allergy symptoms.

Is Benadryl processed by the liver or kidneys?

Diphenhydramine undergoes extensive first-pass metabolism, whereby 50–60% of ingested medication is metabolized by the liver before reaching the systemic circulation. Nearly all the available drug is metabolized by the liver within 24–48 hours, thus increasing risk for liver injury.

How do you get Benadryl out of your system fast?

Hydration: The more water you drink, the quicker diphenhydramine is flushed from the system. Metabolism: Everyone's body metabolizes or breaks down drugs and similar substances at a different rate. The faster your drug metabolism is, the less time diphenhydramine stays in your system.

How does Benadryl affect the elderly?

Fall Risk. Diphenhydramine can cause decreased reaction times and dizziness. In older people with other medical problems or physical impairments, this may lead to falls or accidents, especially while getting up to urinate at night.

How long does Benadryl take to work?

How long does it take diphenhydramine (Benadryl) to start working? Diphenhydramine (Benadryl) starts to work pretty quickly. You can expect to it to kick in within about 15 to 30 minutes. Its full effects can be felt around 2 hours after your dose.

Can Benadryl make you feel weird?

In some people, taking Benadryl can actually have a stimulant effect, which is called paradoxical excitation. People that experience this after taking Benadryl may report feeling: excitable. nervous.

Is Benadryl good for anxiety?

Advantages. One of the biggest advantages of using an OTC medication such as Benadryl to treat anxiety is that it is fast-acting and convenient. These qualities can be helpful if you need to reduce symptoms of mild anxiety quickly. Because Benadryl causes many people to feel drowsy, it can also help with sleep.

Does Benadryl make you sleepy?

First-generation antihistamines such as diphenhydramine (Benadryl®) usually cause drowsiness because they are less likely to affect the histamine produced in the brain or have other unwanted effects in the brain.

How can I sleep without sleeping pills?

The Do's:

  1. Stick to a regular sleep schedule (same bedtime and wake-up time), seven days a week.
  2. Exercise at least 30 minutes per day most days of the week. ...
  3. Get plenty of natural light exposure during the day. ...
  4. Establish a regular, relaxing bedtime routine.
  5. Take a warm bath or shower before bed.

What is the strongest over-the-counter sleeping pill?

Doxylamine succinate is one of the most sedating antihistamines available over-the-counter (stronger than diphenhydramine). A single dose causes rapid and marked drowsiness in the vast majority of individuals. Doxylamine succinate is eliminated somewhat more slowly from the body than diphenhydramine hydrochloride.