Many patients have used Benadryl (diphenhydramine) for years without thinking much about it.

Feel cruddy during allergy season? Pop a Benadryl.

Can’t sleep, take a Benadryl. Bee sting? Yep, Benadryl.

These kinds of uses are what cause it to sit in medicine cabinets across the world.

And because it is sold over the counter, many assume it must be fairly harmless.

I understand why, too, no one’s really questioning Benadryl because of how commonplace it is.

But in medicine, people assume familiar is the same as low-risk.

What we’re finding more and more is that that simply isn’t the case.

In fact, Benadryl may be doing quite a bit of damage if used without thinking through what happens.

But Really, What is Benadryl?

Benadryl’s active ingredient is diphenhydramine, one of the first antihistamines ever developed. It was introduced in the 1940s and was once an important medication. At the time, it gave doctors and patients a way to block histamine, the chemical that drives many allergy symptoms like itching, sneezing, watery eyes, and a runny nose.

Benadryl’s long-established use in pharmacology may have contributed to some of its risks being underrecognized by the public, despite growing concerns within the medical community about certain side effects and long-term implications.

You see, the problem is that diphenhydramine does more than block histamine.

It also crosses the blood-brain barrier and has strong anticholinergic effects, meaning it interferes with acetylcholine.

I’ve written quite a bit about acetylcholine because it’s one of the most significant nervous-system messengers and is involved in memory, attention, digestion, bladder function, heart rhythm, and other automatic body functions.

That is why Benadryl can make people sleepy… and people who use it to go to sleep are actually inviting trouble.

A 2025 review in the World Allergy Organization Journal argued that diphenhydramine has reached the end of its useful medical life cycle because newer antihistamines offer similar allergy relief with fewer side effects.

One issue with diphenhydramine is that it can impair reaction time, memory, focus, and coordination. In one randomized driving-simulator study, diphenhydramine impaired driving performance more than alcohol did, and participants were not always good at judging how impaired they were.

People often “feel fine” while the medication is coursing through their body, but that doesn’t mean their brain is functioning normally.

Older adults who take it are especially vulnerable.

As people age, they often clear medications more slowly, and anticholinergic drugs can increase the risk of confusion, falls, constipation, urinary retention, dry mouth, blurry vision, and next-day grogginess.

Children can also react unpredictably. Some become sedated. Others become agitated or hyperactive. In overdose situations, diphenhydramine can be dangerous.

This is why physicians are often slow to recommend it to young children.

So when a patient tells me they are using Benadryl several nights a week for sleep, or using it all season for allergies, I usually want to know “why?”

“Why is the body needing this much symptom suppression?”…as there’s usually something further upstream that needs to be addressed.

That is where integrative and functional medicine can help. Not by replacing medical care, and not by telling people to stop medications abruptly. But by looking at the terrain underneath the symptom.

If allergies are the issue, we need to think beyond “block histamine.” Histamine is part of the immune system’s alarm response. The goal is not to shut the immune system down completely. The goal is to understand why the alarm keeps going off.

There is also a bigger safety issue with anticholinergics, and this made the news recently, so I wanted to pass it on to you.

A 2026 population-based study in BMC Medicine followed more than 508,000 adults in Stockholm and found that higher cumulative exposure to anticholinergic medications was associated with a greater risk of cardiovascular events, including heart failure, arrhythmias, heart attacks, and strokes. The highest exposure group had a 71% higher risk compared with nonusers. This was observational research, so it cannot prove cause and effect, but the dose-response pattern is worth taking seriously.

Another long-term study of more than 21,000 adults in the EPIC-Norfolk cohort found that greater anticholinergic burden was associated with a higher risk of cardiovascular disease and mortality over 10 years.

This is why I encourage patients to review their medication list with their clinician or pharmacist, especially if they are older, taking several medications, or using over-the-counter sleep and allergy products regularly.

You don’t want to assume a product is completely safe, only to combine it with something else that could create unexpected or potentially harmful health risks.

You Could Use These Instead of Benadryl

When trying to use Benadryl as sparingly as possible, it’s a good idea to focus on the cause of the issues.

Sometimes an allergic trigger is obvious: pollen, pets, mold, dust mites, or seasonal changes. Sometimes what’s causing your allergic reaction could be less obvious: things like poor indoor air quality, chronic sinus inflammation, reflux irritating the airway, disrupted sleep, high stress, or a diet that leaves the immune system more reactive.

Below are some options.

1 – Nasal Rinses:

If you deal with allergic rhinitis, nasal saline irrigation has evidence supporting its use as an add-on.

Sure, spraying something up your nose isn’t as fun as taking a pill, but a Cochrane review found that saline irrigation may improve symptoms in adults and children with allergic rhinitis compared with no irrigation, with generally low risk when done properly.

That does not mean a nasal rinse cures allergies. But they can reduce the allergen load sitting on the nasal lining. Think of it like rinsing pollen off the windshield. It does not change the weather, but it can help you see and breathe a little better.

2 – Other Medications:

Medication choice also matters. Newer-generation antihistamines are generally less sedating than older first-generation drugs like Benadryl (diphenhydramine). A review in Allergy, Asthma & Clinical Immunology notes that newer antihistamines have a better safety profile and are recommended first-line for mild allergic rhinitis and urticaria.

In this case, I’m not trying to make a case for “natural versus medicine,” just showing there is better medicine. As stated in the article, “Loratadine, fexofenadine, desloratidine, rupatadine and bilastine are the least-sedating antihistamines and, presently, loratadine, fexofenadine and desloratidine are the sanctioned choices for pilots, truck drivers and others who perform complex tasks like operating heavy machinery vs. cetirizine, which is a low-sedating antihistamine.”

And sometimes medical treatment should go deeper than daily symptom control. For the right patient, allergen immunotherapy can help retrain the immune response over time. The 2020 rhinitis practice parameter discusses diagnosis and treatment selection for allergic and nonallergic rhinitis, including evidence-based medical options.

3 – Vitamins and Nutritional Supplements:

On the integrative side, nutrition can support the body’s handling of histamine.

Vitamin C has been studied in relation to histamine. Older human research found that oral vitamin C lowered blood histamine levels in a small group of volunteers, and later research has continued to explore vitamin C’s role in histamine metabolism.

That does not make vitamin C a replacement for allergy medication. But it does suggest that nutrient status may influence how reactive the system feels. Plus, you derive many, many more tangible benefits from vitamin C supplementation that medications cannot provide.

Quercetin is another nutrient that can help with allergies. This plant flavonoid (that I’ve written about before) is found in foods like onions, apples, and berries. Much of the strongest mechanistic evidence is preclinical, but research suggests quercetin can influence mast cells, the immune cells that release histamine and other inflammatory chemicals.

And it needs to be said again.

An integrative approach isn’t about swapping Benadryl for a supplement and calling it a day…though there are times when you can swap out a medicine for an integrative technique.

Doing that is still a symptom-chasing mindset. We want to chase the root cause.

The better approach is to lower the body’s total inflammatory and histamine burden while using the safest effective medications for symptoms as needed.

That may mean cleaning up the bedroom environment, using dust-mite covers, addressing mold exposure, improving air filtration, rinsing the nose safely with sterile or previously boiled water, stabilizing blood sugar, reducing alcohol if it worsens symptoms, and getting enough sleep. It may mean treating reflux, supporting gut health, or identifying food patterns that seem to worsen congestion or itching.

So Should You Ditch Benadryl?

Look, Benadryl may still have a role in certain situations, and emergency allergy care should always be taken seriously.

But for routine allergies or sleep, many patients have safer options and better long-term strategies.

The practical path is simple: identify triggers, reduce exposure where possible, support the body’s histamine metabolism, choose lower-risk medications when medication is needed, and revisit the medication list regularly.