Can You Mix Benadryl and Alcohol?

Mixing Benadryl and alcohol may seem harmless to some, especially when both substances are readily available over the counter and used commonly in everyday life. However, combining them can lead to dangerous outcomes due to their effects on the central nervous system (CNS).

Whether you’re seeking relief from itchy skin, a runny nose, or trying to get a good night’s sleep, it’s crucial to understand the serious risks of mixing diphenhydramine—the active ingredient in Benadryl—with alcohol.

What Is Benadryl?

Benadryl is a brand name for diphenhydramine, an antihistamine commonly used to treat allergy symptoms such as sneezing, a runny nose, itchy skin, and hives. It is also found in some cough syrup formulas and marketed as a sleep aid due to its sedative effects.

Diphenhydramine works by blocking histamine, a chemical released by the immune system during allergic reactions.[1] It’s available in various forms, including tablets, capsules, and liquids, and can be found at grocery stores, pharmacies, and online.

While effective for reducing allergy symptoms, it is also a central nervous system depressant. This becomes particularly concerning when combined with alcohol, another CNS depressant.

Understanding Alcohol as a CNS Depressant

Drinking alcohol affects the central nervous system, including the brain and spinal cord. It slows down communication between nerve cells, which can impair mental alertness, coordination, and the ability to perform physical and mental tasks.[2]

Alcohol, especially when consumed in moderate to high quantities, leads to drowsiness, dizziness, slurred speech, and, in severe cases, respiratory depression, seizures, or liver failure.

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), 29.5 million people aged 12 and older in the U.S. had alcohol use disorder (AUD) in 2021—an indication of how widespread and risky alcohol abuse is.[3]

Why Mixing Benadryl and Alcohol Is Dangerous

When you mix Benadryl with alcohol, you’re combining two CNS depressants. This can increase drowsiness, significantly impair coordination, and dangerously reduce your body’s ability to function normally.

The main risks of combining alcohol and Benadryl include:[4]

• Extreme Drowsiness: Both substances cause sedation. Taken together, they can result in excessive sleepiness, making it unsafe to drive or operate machinery.
• Respiratory Depression: This is a life-threatening condition where breathing slows or stops entirely. The risk increases with higher doses or in individuals with existing respiratory issues.
• Impaired Coordination and Mental Alertness: Performing even basic mental tasks becomes difficult, increasing the chance of accidents.
• Liver Strain: Both substances are metabolized by the liver. Mixing them places an extra burden on this vital organ, potentially leading to liver damage over time.
• Unpredictable Interactions with Other Medications: If you’re taking other medications, especially prescriptions for sleep, anxiety, or pain, the interaction can be unpredictable and dangerous.
• Cognitive Impairment: Memory lapses, confusion, and poor judgment may occur—especially in older adults.

Special Considerations for Older Adults

Aging slows the body’s ability to process medications and alcohol. Older adults are at a higher risk of complications from mixing Benadryl and alcohol. The American Geriatrics Society recommends avoiding diphenhydramine altogether for older adults due to increased sensitivity to its sedative effects.[5]

Even small amounts of alcohol in this age group can cause disproportionate CNS effects, putting them at risk of falls, hospitalization, and cognitive decline.

Can Small Amounts Be Safe?

There is no universally safe amount of alcohol to consume when taking diphenhydramine. Even small amounts can lead to impaired coordination and slowed breathing, depending on your body weight, age, tolerance, and whether you’ve taken other substances.

The recommended dosages of diphenhydramine assume no alcohol is in your system. Deviating from this recommendation can result in adverse side effects.

Substance Abuse and Risk of Dependency

While Benadryl is available over the counter, it is not without risks. Some people misuse diphenhydramine to get a good night’s sleep or to self-medicate for anxiety. Combined with regular drinking, this can lead to substance abuse or dependency on both substances.

The Centers for Disease Control and Prevention (CDC) reports that excessive alcohol use contributes to 140,000 deaths in the U.S. each year.[6] When combined with drugs—even over-the-counter ones—the increased risk of life-threatening interactions rises.

Signs of an Overdose

An overdose of Benadryl and alcohol can be fatal. Be aware of the following warning signs of Benadryl and alcohol poisoning:

• Confusion or hallucinations
• Slowed or irregular heartbeat
• Difficulty breathing
• Extreme drowsiness or unconsciousness
• Seizures
  

If you or a loved one shows these signs after mixing alcohol and diphenhydramine, call emergency services immediately.

Safe Alternatives for Allergy Relief

If you suffer from allergy symptoms and still want to enjoy a glass of wine or beer occasionally, consider non-drowsy antihistamines like loratadine (Claritin) or fexofenadine (Allegra), which are less likely to cause CNS depression.

However, you should always consult a doctor or pharmacist before combining any medications with alcohol.

Safe Alternatives for Sleep

For those using Benadryl as a sleep aid, it’s worth exploring safer, non-drug options:

• Sleep hygiene practices like turning off screens an hour before bed
• Avoiding alcohol content in beverages before bed
• Using white noise or meditation apps
• Cognitive Behavioral Therapy for Insomnia (CBT-I)
  

If sleep difficulties persist, speak with a healthcare provider before reaching for substances that can interact dangerously.

What to Do If You’ve Already Combined Benadryl and Alcohol

If you’ve already mixed Benadryl and alcohol—intentionally or unintentionally—monitor your symptoms closely. Avoid driving or engaging in any activity that requires mental alertness or physical coordination.

If you feel lightheaded, drowsy, or have difficulty breathing, seek medical help. In a safe environment, you may be able to sleep off the effects, but it is better to err on the side of caution, especially if you’ve consumed large amounts.

Get Connected to an Alcohol Addiction Treatment Center

Mixing alcohol and Benadryl is a combination best avoided. The risks to your central nervous system, liver, and overall health are too high—even with small amounts of either substance.

Always follow recommended dosages, and consult your doctor or pharmacist if you’re unsure about potential interactions. Being informed and cautious is the best way to protect your health and the well-being of those around you.

If you are mixing alcohol and Benadryl due to an alcohol use disorder, it’s time to seek professional help. At 1st Step Behavioral Health, we use evidence-based treatments to help our clients recover. Contact us today for more information on how we can help you overcome alcoholism.

Frequently Asked Questions (FAQ)

1. How long should I wait after taking Benadryl before drinking alcohol?

It’s generally recommended to wait at least 24 hours after taking Benadryl before consuming alcohol. Diphenhydramine can stay in your system for several hours, depending on your metabolism, age, and dosage. To avoid interactions, always err on the side of caution and consult your healthcare provider.

2. Can I drink alcohol if I took Benadryl the night before?

Possibly, but it depends on your body’s elimination rate and the amount of Benadryl taken. For most healthy adults, Benadryl’s effects wear off after 6–8 hours, but the drug may linger longer in your system. If you still feel drowsy or “off,” it’s best to avoid alcohol until you’re fully alert and symptom-free.

3. Is it safe to use Benadryl for sleep if I occasionally drink alcohol?

Using Benadryl as a regular sleep aid is not advised, especially if alcohol is also used recreationally. Over time, this combination can contribute to tolerance, dependence, and reduced sleep quality. Better sleep strategies or non-sedating alternatives should be explored with a doctor.

4. What other medications should not be mixed with alcohol?

Many CNS depressants and other drugs can interact dangerously with alcohol, including:

• Benzodiazepines (e.g., Valium, Xanax)
• Opioids
• Muscle relaxants
• Antidepressants
• Over-the-counter sleep aids

Always read medication labels and consult a pharmacist or doctor to ensure safe use.

5. Why does Benadryl make me feel more drunk when I’ve only had one drink?

Because Benadryl and alcohol both depress the central nervous system, they amplify each other’s effects. Even a small amount of alcohol can feel stronger if Benadryl is still active in your system, leading to greater drowsiness, impaired coordination, or even confusion.

6. Are there safer allergy medications to use if I drink alcohol socially?

Yes. Non-drowsy antihistamines such as loratadine (Claritin) or fexofenadine (Allegra) are less likely to cause sedation and may be safer if consumed with moderate alcohol intake. However, even with these, it’s important to consult your doctor before combining any substance with alcohol.

References:

1. The National Library of Medicine (NLM): Diphenhydramine
2. Harvard Health: This is your brain on alcohol 
3. The National Institute on Alcohol Abuse and Alcoholism (NIAAA): Alcohol Use Disorder (AUD) in the United States: Age Groups and Demographic Characteristics
4. Science Direct: Diphenhydramine: Time to Move on?
5. The State of California: Alternatives to Diphenhydramine for Older Adults
6. The Centers for Disease Control and Prevention (CDC): Addressing Excessive Alcohol Use: State Fact Sheets