Is Benadryl good for a cough?

Quick Answer

Benadryl can be moderately effective at suppressing coughs due to its active ingredient diphenhydramine which has mild antitussive (cough suppressant) properties. However, Benadryl is typically not a first line treatment for coughs. Other over-the-counter cough medications usually contain ingredients better suited for cough suppression. Benadryl is an antihistamine and is more commonly used for allergies or insomnia.

What is Benadryl?

Benadryl is a brand name for the drug diphenhydramine hydrochloride. Diphenhydramine is a first-generation antihistamine that is used to treat allergies, hay fever, insomnia, motion sickness, and symptoms of the common cold and flu such as coughing, sneezing, runny nose, and itchy/watery eyes.

The active ingredient in Benadryl, diphenhydramine hydrochloride, works by blocking the effects of histamine in the body. Histamine is a chemical produced by the body during an allergic reaction that causes many common allergy symptoms. By preventing histamine from attaching to receptors, Benadryl helps provide relief from these allergy symptoms.

Besides allergies, diphenhydramine’s sedating effects make it useful for treating insomnia and motion sickness. It causes drowsiness which helps people fall asleep. The drowsiness is also useful in treating motion sickness as it helps minimize nausea, vomiting, and dizziness from travel.

How Does Benadryl Work for Coughs?

Although not its main use, Benadryl can provide some relief for coughs because of its mildly effective antitussive (cough suppressing) properties.

The diphenhydramine in Benadryl is thought to suppress coughs in two ways:

1. By reducing respiratory tract secretions – Diphenhydramine dries up mucus secretions in the respiratory tract. This helps reduce coughs caused by excessive secretions.

2. Central antitussive effect – Diphenhydramine is thought to act on the cough center in the brain to minimize the urge to cough.

So by drying up mucus secretions and suppressing the cough reflex, diphenhydramine and therefore Benadryl can provide modest short-term cough relief.

However, diphenhydramine is not considered very potent for treating coughs. Its antitussive effects are relatively mild compared to other common over-the-counter cough medicines. Therefore, Benadryl is not usually a first line treatment for coughing.

Is Benadryl Recommended for Coughs?

Benadryl is not typically recommended as a primary treatment for relieving coughs. While its active ingredient diphenhydramine does have mild cough-suppressing effects, there are other over-the-counter remedies that are more effective and formulated specifically for coughs.

Some key reasons Benadryl is not a first choice include:

– Its antitussive effect is relatively mild and short-acting. Better options exist for suppressing coughs.

– The antihistamine effects are not useful for coughs from colds/flu. These are not allergic reactions.

– The sedating side effects can be undesirable for daytime cough relief.

Instead, cough medications containing dextromethorphan or guaifenesin as the active ingredients are superior for cough suppression. They act directly on the cough reflex and respiratory tract secretions.

Benadryl could be used as an adjunctive treatment if your cough persists after taking medications containing dextromethorphan or guaifenesin. But it should not generally be used as the sole treatment.

More Effective OTC Cough Medicines

Instead of Benadryl, some over-the-counter cough medications that are more effective options include:

Dextromethorphan (DXM)

Dextromethorphan directly acts on the cough center in the brain to suppress the urge to cough. Brand names containing dextromethorphan include Robitussin, Delsym, and Vicks Cough.


Guaifenesin works by thinning mucus secretions in the airways, making coughs more productive. It is found in Mucinex, Robitussin Chest Congestion, and many other OTC cough medicines.

Cough Suppressant/Expectorant Combos

Many over-the-counter cough formulas combine dextromethorphan with guaifenesin for dual action relief. Examples include Robitussin Dual Action and Vicks DayQuil Cough.


Benzonatate numbs receptors in the lungs to prevent cough reflex triggered by irritation. Brand names are Tessalon Perles and Zonatuss.

So in summary, medicines specifically designed and formulated to treat coughs are recommended over Benadryl. Benadryl can be used as an adjunctive treatment but should not be your only remedy for a cough.

Benadryl Dosage for Coughs

If you do wish to use Benadryl to help quiet a cough, here are the recommended dosages:

For adults and children over age 12: Take 25-50 mg diphenhydramine every 4-6 hours as needed. Do not exceed 300 mg per day.

For children ages 6-12: Take 12.5-25 mg diphenhydramine every 4-6 hours as needed. Do not exceed 150 mg per day.

Do not give Benadryl to children under 6 years old without first consulting a pediatrician.

Note that the liquid forms of Benadryl contain a lower diphenhydramine concentration. Refer to the dosing instructions on the liquid product you have.

It’s best to take Benadryl for coughs during the nighttime hours. This takes advantage of its sedating effect to promote sleep and provides longer lasting cough relief.

Safety and Side Effects

Benadryl is generally safe when used occasionally and as directed. However it does have side effects to be aware of, especially when using it for coughs.

Potential side effects include:

– Drowsiness – This can impair driving and is more likely when taking it during the day.

– Dry mouth

– Dizziness

– Nausea, vomiting, stomach upset

– Headache

– Fatigue

– Paradoxical hyperactivity in children

Benadryl should be avoided in people with the following conditions:

– Prostate enlargement

– Glaucoma

– Pregnancy or breastfeeding (talk to your doctor)

– Dementia

You should also talk to your doctor before giving Benadryl for coughs to children with any medical conditions. Never exceed the recommended Benadryl dosage as it could cause serious medical complications.

Other Tips for managing coughs

While medications can help suppress coughing, there are other remedies that can provide additional relief:

– Use a humidifier – Warm, moist air can soothe airway irritation and loosen mucus. This helps reduce coughing episodes.

– Drink plenty of fluids – Staying hydrated can thin out mucus.Aim for water, herbal tea, soup broths.

– Use cough drops/lozenges – These provide local anesthetic relief for irritated throat tissues.

– Try honey – Honey has cough-calming properties. Take it alone or in tea. Not for infants!

– Avoid smoke/chemical irritants – These can trigger coughing. Stay away from them.

– Use OTC nasal sprays – Saline sprays help keep nasal passages moisturized.

– Try menthol rubs – Applying mentholated rubs to the chest can have a soothing, cooling effect.


Benadryl contains the antihistamine diphenhydramine which has mild cough-suppressing effects. However, it is not considered a very potent or effective antitussive (cough medicine) when compared to other options. The diphenhydramine found in Benadryl can help dry up respiratory secretions and may mildly inhibit the cough reflex in the brain. But its antitussive properties are relatively short-acting and unimpressive.

Better over-the-counter alternatives specifically for cough relief include dextromethorphan and guaifenesin. These target the cough reflex and reduce mucus secretions more effectively than diphenhydramine. Benadryl is an antihistamine and allergy medication first and foremost. While it can be used as an adjunctive treatment, Benadryl should not be used as the sole remedy for cough relief.

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