Why Mixing Benadryl and Alcohol is a Recipe for Danger

When allergies are a bother, reaching for an over-the-counter pill is common. Pills like Benadryl can help with seasonal allergies. But because of their sedative qualities, some people abuse them for other purposes, like falling asleep. 

Alcohol, equally available at stores, can be turned to as a sleep aid, too. Studies have found that nearly thirty percent of people with insomnia use alcohol as a sleep aid. 

So, what happens when the two are combined?

Benadryl and Alcohol: How They Work

Both Benadryl and alcohol work on several parts of the body, but when combined, the risks have to do with the CNS or central nervous system. 


The main ingredient in Benadryl is diphenhydramine. Diphenhydramine is an antihistamine that also has local anesthetic properties. It reverses stimulation of the histamine one receptor, responsible for things like:

  • Vasodilation
  • Coughing
  • Allergy immune responses

More importantly, though, it can cross through the blood-brain barrier and interfere with histamine 1 CNS receptors. This is what suppresses the cough center and causes drowsiness. 

The drowsiness caused by a suppressed response within the body is the main reason medications like Benadryl come with warnings against taking the medication and driving or operating heavy machinery. 

With too much Benadryl, your central nervous system becomes depressed. This can cause serious side effects like:

  • Increased heart rate
  • Flushing
  • Sleepiness
  • Problems with cognition 


Alcohol crosses through membrane barriers to reach several parts of the body quickly. It can impact the brain and central nervous system. 

Excessive drinking interferes with brain receptors, stopping communication. It also suppresses activities along the nerve pathways. By suppressing the central nervous system, alcohol causes:

  • Drowsiness 
  • Memory problems
  • Sedation 

Benadryl and Alcohol: Dangers of Mixing the Two

One of the side effects of alcohol is drowsiness as well. Because of this, many people think that alcohol can be a generic sleep aid and that mixing a dose of Benadryl with a beer or a glass of wine may improve the chances of getting a good night’s sleep.

Benadryl is an over-the-counter medication prescribed for the treatment of allergies only. It’s not something you’re supposed to use for any other purpose, but that doesn’t stop people from relying on Benadryl as a generic form of sleep aid because drowsiness is one of the side effects.


There are serious risks involved in mixing Benadryl and alcohol. Alcohol (like other benzos) increases the sedative impact that diphenhydramine can have.

Both substances can cause:

  • Severe drowsiness
  • Severe sedation
  • Difficulty with concentration
  • Problems with physical tasks

This means that a combination of Benadryl and alcohol, while both technically over-the-counter and perfectly legal, can cause severe drowsiness, dizziness, and problems with concentration. Moreover, the side effects might inhibit sleep rather than help with sleep.

There is a risk that Benadryl will negatively interact with other medications you are using, and alcohol can commonly interfere with prescription medication. 

Can you OD on Benadryl and Alcohol?

Yes, there is a risk of overdose when mixing Benadryl and alcohol as both inhibit central nervous system function. The quantities required would be quite high, but alcohol poisoning can happen with or without Benadryl. 

Getting Professional Treatment

If you are struggling with alcoholism or find yourself mixing several drugs outside of their prescribed purpose, it might be time to get professional treatment for substance abuse. 

Marina Harbor offers clients professional alcohol detox and inpatient recovery for substance abuse. With our inpatient programs, clients have a chance to step away from their daily lives and fully immerse themselves in a healing program overseen by medical teams who care. 

Programs can include:

  • Health meals prepared daily
  • Relapse prevention education
  • Breathwork
  • Drama therapy
  • Yoga
  • Art therapy
  • Walks
  • 12-step recovery meetings
  • Private rooms
  • Exercise fitness programs
  • Boxing 

These programs provide a chance to manage stress that might otherwise contribute to poor sleep or triggers in a way that does not lead to reliance on over-the-counter medications or substance abuse. 

If you are abusing several substances in conjunction with Benadryl, like other prescription benzodiazepines or marijuana, we also have several programs that can be personalized to multiple substance addictions. With an easy and fast evaluation, we can help you find a customized treatment plan that really works.

You deserve to live a healthy, happy life. Call our team today to learn how we can help.

Request a Confidential Callback 24/7

The Latest Blog

Stay Up to Date with All Things Addiction & Recovery.

Escape the Chaos of Addiction Today

Here at Marina Harbor Detox we understand that no two clients are alike. We offer each and every client a unique experience that fits their individual needs when seeking treatment for addiction. Our San Francisco drug and alcohol rehab center provides the perfect escape. Here you can focus on healing the core issues that lead to substance abuse in the first place, in a safe and comfortable environment. Our admissions coordinators are standing by day and night to help you find your personal solution. 

Call Now Button