Can I use Benadryl for motion sickness?

October 14, 2025 •

4 min read

Over-the-counter antihistamines are commonly used to prevent motion sickness, and diphenhydramine (the active ingredient in Benadryl) is among them. However, its use for this purpose comes with a high likelihood of causing drowsiness and other side effects, making it an effective option primarily for individuals who can afford to be sedated during travel.

Quick Summary

Benadryl, containing diphenhydramine, is a first-generation antihistamine that can prevent motion sickness, though its use is often limited by significant side effects, particularly drowsiness. It works by blocking histamine and acetylcholine receptors in the brain to reduce nausea and vomiting. For optimal results, it should be taken before symptoms begin.

Key Points

Effectiveness: Benadryl is a first-generation antihistamine that can effectively help prevent motion sickness symptoms like nausea and vomiting if taken proactively.
Primary Side Effect: Its effectiveness is tied to significant drowsiness and sedation, which can impair alertness and coordination.
Timing is Key: For prevention, Benadryl should be taken about 30 minutes before traveling, as it is less effective once symptoms have already started.
Drowsy vs. Less-Drowsy: First-generation antihistamines like Benadryl and Dramamine are sedating, whereas less-drowsy alternatives like meclizine (Bonine) are also effective but cause less impairment.
Alternatives Exist: If you need to stay alert, non-drug options like ginger or focusing on the horizon, or using a medication like meclizine, are preferable to Benadryl.
Consider Children: Benadryl can cause paradoxical hyperactivity in some children and is not recommended for those under two years old; a test dose is advised for older children.
Professional Guidance: Consulting a doctor or pharmacist is the safest way to determine the right dosage and ensure Benadryl is safe for your specific health conditions.

Understanding Motion Sickness and How Benadryl Works

Motion sickness is a common condition caused by a mismatch between the signals your eyes send to your brain and the signals your inner ear sends. The inner ear detects motion, and when it senses movement that isn't visually perceived (like when reading in a car), it can trigger nausea and vomiting.

Benadryl, or diphenhydramine, is a first-generation antihistamine. Its mechanism of action involves blocking histamine-1 receptors in the brain. Since it can readily cross the blood-brain barrier, it also has anticholinergic effects by blocking muscarinic acetylcholine receptors. This action helps to suppress the neural pathways that control nausea and vomiting, providing relief from motion sickness symptoms. Unlike newer, non-drowsy antihistamines, which don't cross the blood-brain barrier as easily, diphenhydramine's central nervous system effects are what make it effective for travel sickness.

Proper Usage and Timing for Motion Sickness

For Benadryl to be effective, it is crucial to take it preventively. According to guidelines, a dose should be taken about 30 minutes before exposure to motion. This is because once symptoms like nausea have already begun, gastric stasis can occur, potentially preventing the medication from being properly absorbed. For short trips, a lower dosage may be sufficient to minimize side effects. It is important to follow dosage instructions from a healthcare professional or the product packaging and not exceed the recommended amount within a 24-hour period.

Potential Side Effects of Using Benadryl

One of the most significant drawbacks of using Benadryl for motion sickness is its side effect profile. Common side effects often include:

Drowsiness and Sedation: This is the most prevalent side effect and is a result of the medication crossing the blood-brain barrier. It can impair alertness, coordination, and the ability to operate machinery or drive.
Dry Mouth: The anticholinergic effects can lead to dry mucous membranes.
Blurred Vision: Some individuals experience temporary blurred vision.
Dizziness: Ironically, while it treats motion sickness-related dizziness, the medication itself can cause dizziness.
Constipation: This is another common anticholinergic side effect.
Paradoxical Effects in Children: In some children, Benadryl can have the opposite effect, causing hyperactivity or agitation instead of drowsiness. For this reason, a test dose is recommended for children before a trip.

Alternatives to Benadryl

For those who need to remain alert or find Benadryl's side effects too bothersome, several alternative options exist. These range from other medications to non-pharmacological approaches. The best choice depends on the duration of travel and personal tolerance.

Comparison of Motion Sickness Medications


Feature	Diphenhydramine (Benadryl)	Dimenhydrinate (Dramamine Original)	Meclizine (Bonine, Dramamine Less Drowsy)	Scopolamine (Transderm Scop)
Drug Class	First-generation antihistamine	First-generation antihistamine	First-generation antihistamine	Anticholinergic
Mechanism	Blocks H1 receptors, significant anticholinergic effects	Blocks H1 receptors and has anticholinergic effects	Blocks H1 receptors, less sedating than diphenhydramine	Blocks acetylcholine receptors in the brain
Primary Use	Allergic reactions, sleep, motion sickness prevention	Motion sickness prevention and treatment	Motion sickness prevention	Motion sickness prevention (long-term)
Primary Side Effect	High drowsiness	Drowsiness	Lower drowsiness	Dry mouth, blurred vision, drowsiness
Duration of Action	4-6 hours	Up to 8 hours	8-24 hours	Up to 72 hours
Administration	Oral tablet, liquid, chewable	Oral tablet, liquid, chewable	Chewable tablet	Transdermal patch (prescription)
Onset of Action	30 minutes	2 hours	2 hours	6-8 hours

Non-Pharmacological Remedies

For those who prefer to avoid medication, or to supplement it, several non-drug options can help alleviate motion sickness:

Focus on a Fixed Point: Staring at the horizon or a fixed point outside the vehicle can help resolve the sensory mismatch.
Choose the Right Seat: In a car, the front seat is often best. On a boat, stay on the deck in the fresh air. On a plane, seats over the wings experience less motion.
Eat Lightly: Avoid heavy, fatty, or spicy foods before and during travel. Small, frequent meals and snacks like dry crackers can help.
Stay Hydrated: Drink plenty of water and avoid alcohol and caffeine, which can exacerbate symptoms.
Use Ginger: Ginger root has been used traditionally and is supported by some studies to help with nausea. Ginger chews, tea, or candies are easily accessible options.
Acupressure Bands: Some find relief using wristbands that apply pressure to the P-6 acupressure point on the wrist.

Important Safety Considerations

Before using Benadryl or any other medication for motion sickness, it is important to consider individual health factors and consult a healthcare professional. Individuals with certain conditions, such as glaucoma, prostate disease, or liver and kidney issues, should exercise caution. It is also not recommended for children under the age of two. Always read and follow the dosage instructions on the packaging or from a doctor.

Conclusion

In short, can I use Benadryl for motion sickness? Yes, it is an effective option, especially for preventive use. However, its effectiveness comes at the cost of potential and significant drowsiness, which may not be suitable for all travelers. For those needing to stay alert, less-drowsy alternatives like meclizine or non-pharmacological methods may be more appropriate. Ultimately, assessing your personal needs for sedation, trip duration, and severity of symptoms will guide your decision toward the most suitable remedy. For long trips or intense motion sickness, a prescription option like a scopolamine patch may be more effective and last longer. A conversation with a doctor or pharmacist is the best way to ensure you choose the safest and most effective solution for your travel plans.

More information on motion sickness

For comprehensive guidance, you can refer to the Centers for Disease Control and Prevention's detailed page on motion sickness.

Frequently Asked Questions

Benadryl (diphenhydramine) is a first-generation antihistamine that helps with motion sickness by blocking certain chemical receptors in the brain. This action helps to suppress the neural pathways that trigger nausea and vomiting in response to motion.

For optimal effectiveness in preventing motion sickness, you should take Benadryl approximately 30 minutes before your journey begins. Taking it too late, especially after nausea starts, may be less effective as absorption can be affected.

The most common and notable side effect of using Benadryl for travel is significant drowsiness. Other side effects can include dry mouth, blurred vision, and dizziness.

Dramamine (dimenhydrinate) contains the same active ingredient, diphenhydramine, combined with a mild stimulant to slightly counteract the sedative effect. Both are effective, but some people find Dramamine preferable due to the slightly reduced drowsiness, although it is still a sedating medication.

Yes, less-drowsy options like meclizine (Bonine, Dramamine Less Drowsy) are available and are also effective at preventing motion sickness. However, non-drowsy second-generation antihistamines for allergies, such as cetirizine (Zyrtec), are not effective for motion sickness.

While it is sometimes used, healthcare professionals advise caution. In some children, Benadryl can cause paradoxical effects like hyperactivity rather than drowsiness. It is not recommended for children under two, and a test dose is often advised for older children.

Non-drug remedies include focusing on the horizon, getting fresh air, eating light meals and staying hydrated, and using ginger candies or acupressure wristbands. Choosing the right seat in a vehicle can also make a significant difference.

If Benadryl is not effective, you should consider a stronger option like a meclizine or scopolamine patch (prescription only) for longer-term travel. Consulting a healthcare provider is recommended to find the best medication and dosage for your needs.