Can You Take Unisom Every Night?

In the long term, Unisom may make sleep even harder to come by.
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Unisom might help you out of a short sleep rut, like when you're jet-lagged or unusually stressed. But what if you're relying on it night after night to help you drift off?


Here, learn about Unisom's ingredients, the side effects of taking Unisom every night and alternatives that can help you get the rest you need.

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What's In Unisom, Anyway?

Unisom's ingredients vary a bit depending on the exact product you're using. Some formulations contain doxylamine, while others contain diphenhydramine. Both are antihistamines that can help relieve occasional sleeplessness.

They're most effective at helping people fall asleep, but not as useful for helping people stay asleep, explains Sudha Tallavajhula, MD, sleep neurologist with UTHealth Houston and Memorial Hermann.

Diphenhydramine and doxylamine work against histamine, a chemical in the brain that promotes wakefulness, says Steven Feinsilver, MD, director of the Center for Sleep Medicine at Northwell Lenox Hill Hospital in New York City.


(The ingredients also ease allergy symptoms like itching, sneezing and watery eyes, which is why you'll find them in antihistamines like Benadryl.)

How Often Should You Take Unisom?

Over-the-counter sleep meds like Tylenol PM and Unisom are meant to deliver short-term relief for temporary sleep problems. It's OK to take them for a few days if you're jet-lagged or dealing with intense stress. But according to the ‌Journal of Clinical Sleep Medicine‌, they're not intended to be a treatment for insomnia.


If you're taking Unisom for more than two or three days at a time, talk to your doctor to see if you might have an underlying sleep issue (more on that in a moment).

Possible Long-Term Effects of Unisom

1. You Could Develop a Tolerance

So what might happen if you were to take Unisom every night? While it might help you nod off at first, there's a good chance that, over time, you'll start to develop a tolerance to the med.



"You might get used to the sleep-inducing effects," Dr. Feinsilver says.

If that happens, you could find yourself taking an increasingly higher dose to fall asleep. Which leads us to our next point.

2. You're More Likely to Overdose

High doses of diphenhydramine or doxylamine are more likely to cause negative side effects like dry mouth, dizziness and daytime grogginess.


Taking very high doses of either med can also cause serious problems like a rapid pulse or trouble urinating, Dr. Feinsilver adds.

3. You Might Get Rebound Insomnia

If and when you do decide to stop taking the medication, there's a good chance your sleep problems will come back even worse than before, notes the Cleveland Clinic.


4. It May Be Masking an Underlying Sleep Condition

There's one more thing to keep in mind: If you regularly need an over-the-counter sleep aid like diphenhydramine or doxylamine (or a natural one like melatonin) to fall asleep, it's possible you have an underlying sleep problem that isn't being addressed, Dr. Tallavajhula says.

In that case, you're better off seeing a sleep specialist who can evaluate your symptoms and recommend treatment that's tailored to managing the condition. (Like using a CPAP machine for sleep apnea, for instance.)


Who Should Not Take Unisom?

Unisom and other sleep meds that have diphenhydramine or doxylamine aren't safe for everyone. Both drugs can potentially raise the risk of dementia for adults older than 65. Older adults are also more likely to experience intense side effects like agitation, dizziness, nausea, constipation, dry mouth or headache, the Cleveland Clinic says.


Unisom also isn't a good choice for people who are pregnant or breastfeeding, according to the Mayo Clinic, or for people with the following conditions:

  • Glaucoma
  • Peptic ulcer
  • Urinary retention


Unisom may interact with medications you're taking, so talk to your doctor first. You should also avoid taking Unisom with alcohol or other sedatives because this can increase the risk for harmful side effects.

Alternatives to Taking Unisom

If you're struggling with sleep for more than a few days, it's a good idea to take a look at your nighttime habits and bedtime routine. There's a good chance you might find opportunities for easy adjustments that can help you wind down before bed and fall asleep easier.

Here's what Dr. Feinsilver recommends:

  • Set a wake time and bedtime and stick to them.‌ Waking up at the same time every morning will help prime your body for sleep at the same time every evening.
  • Move your body outside in the morning.‌ Early exposure to natural light and physical activity can both help you sleep better.
  • Only use your bed for sleep and sex.‌ You'll have an easier time dozing off if your brain only associates your bed with sleep.
  • Clear your brain with a to-do list.‌ Take a few minutes in the early evening to write down any concerns or things you need to get done for tomorrow, then put the list away. "It's a preemptive strike to the things you'll wake up and think about," Dr. Feinsilver says.
  • Do something relaxing before bed.‌ Reading, journaling, yoga, meditating or listening to music all fit the bill.
  • If you can't sleep, get out of bed for a little while.‌ If you're up for more than 15 or 20 minutes, go elsewhere to do another quiet activity (like reading). Then go back to bed when you start to get tired again.

If pain or discomfort is making you toss and turn (which can be a common sleep-stealer when you're pregnant), use a body pillow for some extra support.

Consider turning the thermostat down a little lower, too, to reduce the chances of night sweats waking you up.

So, How Bad Is It Really to Take Unisom Every Night?

It's fine to take Unisom for a few days at a time if you're having a rough patch with sleep. But taking it for longer can do more harm than good.

Plus, you might miss out on beneficial treatment if you have an underlying sleep problem that's not being addressed.




Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.