It’s the middle of the night. You’re wide awake, and sleep is slipping further away.
You think to yourself: Tomorrow is a busy day – I really need some rest.
Your frustration with yourself is growing, and your anxiety about sleep is building.
Before too long, you find yourself falling into your same old desperate habits – scrolling through your phone, checking the clock, turning on Netflix.
Just one episode and I’ll fall asleep, you think to yourself. You know this isn’t true. Even worse, you know these behaviors aren’t doing anything to help you catch some shuteye.
It’s a vicious cycle, one you’ve been stuck in for far too long. And one you’re not sure how to get out of.
For some, Hydroxyzine may be the answer.
Hydroxyzine is an antihistamine, a medication used to reduce the symptoms of an allergic reaction. Think rashes and itchy skin.
But as a side effect, the medication is known to make people calm and drowsy. So many doctors also turn to it for:
- Anxiety
- Insomnia
- Anesthesia
Hydroxyzine isn’t a controlled substance and has a low risk of dependency.
Here we’ll cover how Hydroxyzine works to get you back to sleep when life is keeping you up, as well as how long its sedating effects last.
How Long Does Hydroxyzine Work For Sleep?
As we mentioned above, Hydroxyzine is an antihistamine. These medications block your body from producing a natural chemical in your body histamine.
Histamine impacts your natural sleep-wake cycle, signaling to your body when it’s time to be awake and when it’s time for rest. Less histamine in your system means a better chance for sleep.
Additionally, antihistamines, including over-the-counter versions like Benadryl, are known for creating a calming, drowsy side effect.
When given a Hydroxyzine prescription, you should take it shortly before bed and plan for a full 7-9 hours of sleep.
How Long Does It Take Hydroxyzine To Leave Your System?
Compared to other medications, Hydroxyzine has a long half-life at 20 hours.
A concern with a long half-life is that, in some cases, some of the effects of the medication may stick around longer than you want them to. In the case of Hydroxyzine, this may mean you wake up still feeling groggy and sleepy.
For some, this drowsiness may go away after the first few days of your prescription. Others may require a change in dosage or an alternative treatment altogether.
With this in mind, it’s important to sit down with your doctor to talk about both the advantages and drawbacks of Hydroxyzine. Your doctor will help you weigh the benefits against the risks and determine if this prescription is right for you.
As a final note, Hydroxyzine is meant to be a short-term treatment option for insomnia as it’s been shown to be ineffective in the long run. In fact, those who take their prescription for too long often build up a tolerance to the medication or experience a worsening of their sleep.
Hydroxyzine is a prescription medication. Be sure to consult with a doctor before giving it a try for sleep. Once given a prescription, always follow the directions given to you by your doctor.

Reviewed by Dr. Alex Dimitriu
Dr. Alex Dimitriu is a Stanford-trained physician with dual board certification in psychiatry and sleep medicine. The included content is not intended to replace medical advice. Always be sure to discuss any prescription medications with your doctor.