Can I take 2 Benadryl to sleep? Safety, dosage, and alternatives

October 5, 2025 •

3 min read

According to the U.S. Food and Drug Administration (FDA), Benadryl (diphenhydramine) is indicated for the temporary relief of occasional sleeplessness in adults. While this is a recognized use, it is crucial to understand the associated risks and the drug's limitations before deciding if you can take Benadryl to sleep.

Quick Summary

Taking Benadryl (diphenhydramine) for sleep is a temporary measure for occasional insomnia, but it is not recommended for regular or long-term use. Chronic use can lead to tolerance, dependence, and serious side effects, including impaired cognition. Safer, more effective alternatives exist for ongoing sleep issues.

Key Points

Standard Adult Use: Benadryl containing diphenhydramine is indicated for occasional sleeplessness in adults.
Not for Long-Term Use: Benadryl is not recommended for nightly or long-term sleep aid, as extended use can lead to tolerance and dependence.
Danger of Overdose: Taking more than the recommended amount can lead to serious side effects, including seizures, coma, and even death.
Risk of Cognitive Impairment: Long-term use, especially in older adults, has been linked to a higher risk of cognitive decline and dementia.
Daytime Drowsiness: A common side effect is a 'hangover effect' the next day, which can cause grogginess and impair activities like driving.
Consider Alternatives: For chronic insomnia, non-drug options like CBT-I and improved sleep hygiene are safer and more effective than relying on medication.
Check Labels: Always verify that you are not accidentally doubling up on diphenhydramine by taking other 'PM' medications (e.g., Tylenol PM).

Understanding Benadryl for Sleep

Diphenhydramine, the active ingredient in Benadryl, is indicated for occasional insomnia in adults and children 12 years and older. It is important to follow the product's labeling for appropriate use. Taking this medication about 30 minutes before bedtime is generally recommended to allow it to take effect.

Why Benadryl Causes Drowsiness

Diphenhydramine is classified as a first-generation antihistamine. Its primary mechanism involves blocking the action of histamine, a chemical in the body that plays a role in promoting wakefulness. Because diphenhydramine can cross the blood-brain barrier, it can exert a sedative effect on the central nervous system, leading to drowsiness. This property makes it useful as a temporary sleep aid, but it also contributes to potential side effects like daytime grogginess.

Serious Risks of Using Benadryl Long-Term for Insomnia

While short-term use of Benadryl for occasional sleeplessness may be considered, prolonged use for chronic insomnia is strongly discouraged by medical experts, including the American Academy of Sleep Medicine. There are significant dangers associated with relying on this medication regularly:

Tolerance and Dependence: The body can quickly build a tolerance to the sedative effects of diphenhydramine. Studies indicate that the sleep-inducing benefits can decrease significantly after just a few consecutive doses. This can potentially lead to a cycle of needing to take the medication, which increases the risk of side effects.
Cognitive Impairment: Long-term use of anticholinergic medications like Benadryl has been linked to an increased risk of cognitive decline, memory problems, and even dementia, especially in older adults.
Disrupted Sleep Quality: Benadryl may suppress restorative deep and REM sleep stages, potentially leading to poorer sleep quality even with increased sleep duration.
Rebound Insomnia: After discontinuing regular nightly use, some individuals may experience a temporary worsening of their sleep problems, known as rebound insomnia.

The Dangers of Benadryl Overdose

Taking more than the recommended amount of Benadryl is extremely dangerous and can have severe consequences. The FDA has issued warnings regarding the serious problems associated with high-dose diphenhydramine abuse. Symptoms of an overdose can include:

Severe drowsiness or inability to wake up
Confusion, delirium, or agitation
Hallucinations
Rapid or irregular heartbeat (tachycardia)
Seizures or tremors
Coma or death

Safer Alternatives to Consider

For chronic insomnia, non-pharmacological approaches are often the safest and most effective long-term solutions. Consulting a healthcare provider is essential to determine the root cause of your sleep issues and find a suitable treatment plan.

Comparison Table: Sleep Aids and Methods


Method	Effectiveness for Chronic Insomnia	Risks/Side Effects	Duration of Use	Recommended For
Benadryl (Diphenhydramine)	Low; develops tolerance quickly	Daytime grogginess, dry mouth, long-term cognitive issues	Short-term (under 14 nights)	Occasional, situational sleeplessness
Melatonin	Varies; mild effect for some	Headaches, nausea, dizziness	Short-term	Regulating sleep cycles (e.g., jet lag)
Doxylamine Succinate (Unisom)	Moderate; similar sedative effects to Benadryl	Daytime drowsiness, anticholinergic effects	Short-term	Occasional sleeplessness
CBT for Insomnia (CBT-I)	High; addresses underlying causes	None; requires commitment	Long-term lifestyle change	Chronic insomnia
Valerian Root	Evidence is inconsistent; effectiveness uncertain	Mild side effects like headache and weakness	Short-term, use with caution	Those seeking an herbal option, but with questionable efficacy

Conclusion

While Benadryl containing diphenhydramine is indicated for occasional sleeplessness in adults, it is not a sustainable or healthy solution for chronic sleep problems. Regular, long-term use can lead to tolerance, next-day impairment, rebound insomnia, and potentially serious health consequences, including cognitive issues. Instead of self-medicating with Benadryl for ongoing sleep issues, it is safest and most effective to consult a healthcare professional. For chronic insomnia, a proven treatment like Cognitive Behavioral Therapy for Insomnia (CBT-I), along with improving sleep hygiene, offers a durable solution without the risks associated with medication dependency.

To learn more about the risks associated with anticholinergic drugs, consult reputable sources like those from the JAMA Internal Medicine journal.

Frequently Asked Questions

No, it is not safe to take Benadryl nightly for sleep. The body can quickly develop a tolerance to the sedative effects, and long-term use is associated with serious side effects, including memory problems and an increased risk of dementia, particularly in older adults.

Taking more than the recommended amount of diphenhydramine increases the risk of an overdose. Symptoms can include extreme drowsiness, confusion, hallucinations, rapid heartbeat, seizures, and even coma. Contact Poison Control (1-800-222-1222) or seek emergency medical help if you suspect an overdose.

No, you should never mix Benadryl with alcohol or other sedatives, as this can amplify the sedative effects and increase the risk of slowed breathing, extreme drowsiness, and impaired coordination. Be aware that many OTC 'PM' products already contain diphenhydramine.

Benadryl is intended for occasional, short-term use only. If your insomnia persists, consult a healthcare provider for further evaluation.

Common side effects include a 'hangover effect' or next-day drowsiness, dry mouth, dizziness, impaired coordination, and constipation. These effects can be more pronounced in older individuals.

Safer, long-term alternatives include Cognitive Behavioral Therapy for Insomnia (CBT-I) and practicing good sleep hygiene. Other options include melatonin supplements for regulating sleep cycles or other OTC sleep aids with different active ingredients, but these should also be used with caution.

Benadryl is particularly risky for older adults. They are more susceptible to side effects like confusion, daytime drowsiness, and urinary retention. Studies also indicate a link between long-term anticholinergic use and an increased risk of dementia in this population.