Frequently asked questions

What is Unisom® used for?

Unisom® is an effective and trusted sleep aid indicated for the relief of occasional nighttime sleeplessness due to fatigue or overwork. Unisom® helps to reduce difficulty falling asleep.

How does Unisom® work?

Unisom® contains an antihistamine called diphenhydramine, which temporarily blocks the histamine action that can cause alertness in the central nervous system (CNS).

When should I take Unisom®?

You can take Unisom® about 30 minutes before bedtime.

How long does Unisom® last?

The sedative action of Unisom® may last up to 6 hours.

Can I take Unisom® every night?

Unisom®, non-prescription sleeping pills, should only be used to relieve occasional sleeplessness. If your sleeplessness lasts for more than two weeks, talk to your doctor. Long-term sleeplessness may be an indication of a serious underlying medical illness.

What are the medicinal ingredients in Unisom®?

Each Unisom® SleepGels® Extra Strength capsule and Unisom® Extra Strength tablet contains 50 mg of diphenhydramine hydrochloride.

What are the non-medicinal ingredients in Unisom®?

Each Unisom® SleepGels® Extra Strength capsule contains colourant, gelatin, glycerin, Opacode, polyethylene glycol and sorbitol.

Each Unisom® Extra Strength tablet contains colourant, dibasic calcium phosphate dihydrate, magnesium stearate, microcrystalline cellulose, Opadry, sodium starch glycolate.

Are there side effects associated with Unisom®?

Unisom® may cause drowsiness in the general population and may produce excitation rather than sedation in the elderly and should be avoided in this age group.

Who can use Unisom®?

Unisom® is only recommended for adults and should not be given to children under 12 years of age. Always read the label to make sure Unisom® is right for you, and follow the package instructions carefully.

Can I take Unisom® if I am pregnant or breastfeeding?

You should not take Unisom® if you are pregnant or breastfeeding, unless directed by a doctor.

Where can I buy Unisom® non-prescription sleeping pills in Canada?

Unisom® is an over-the-counter sleeping pill. You can buy Unisom® in most pharmacies or drugstores in Canada without a prescription. Please ask your pharmacist or pharmacy manager if you can’t find Unisom® on the shelf.

What is the safety history of the active ingredient in Unisom®?

The active ingredient in Unisom® has been used for over 50 years in Canada. Diphenhydramine hydrochloride is effective when used as directed.

What should I do in case of accidental overdose?

If you, or someone you know has taken more than the recommended dose of Unisom® (diphenhydramine hydrochloride), call a poison control centre or a doctor immediately, even if there are no symptoms.

Why can’t I sleep?

Having trouble falling asleep and/or staying asleep is often caused by circumstances such as work- or family-related stress, as well as upsetting events. Try to determine what may be hindering your sleep and make simple changes to your daily habits.

What is insomnia?

Insomnia is defined as difficulty getting to sleep and/or staying asleep, waking up too early, and trouble sleeping despite adequate opportunity and circumstances for sleep.

Insomnia can be acute or chronic. Acute insomnia is a short-term problem that is generally the result of stress or change (new job, final exams, illness). It generally lasts only a few nights or a few weeks, and an over-the-counter sleep aid may help you relieve occasional nighttime sleeplessness. Chronic insomnia is a long-term problem in which a person experiences inadequate quantity or quality of sleep for at least 30 days. If this describes you, see a physician or a sleep specialist. Learn more.

How does insomnia start?

Insomnia is often the result of a physical or psychological factor. Although chronic insomnia is usually the result of an underlying medical condition, acute or occasional insomnia may be caused by a current event or circumstance, for example, consuming caffeine, nicotine, and alcohol; jet lag; a job shift change; stress and anxiety; hormonal fluctuations during the menstrual cycle, as well as other factors such as sleeping next to a snoring partner or pregnancy.

How can I help relieve insomnia?

For occasional sleeplessness, over-the-counter sleeping aids can help. Mild or occasional insomnia is often preventable or alleviated by practising good sleep habits and using an over-the-counter sleeping aid. Learn more.

For more serious cases of sleeplessness, lasting more than two weeks, you should consult a healthcare professional. Insomnia may be a symptom of a serious underlying medical illness.

How does insomnia affect the body and brain?

Sleep is essential to our body and mind. While we sleep, our body and brain perform the following activities:

  • Growth hormones, vital to proper physical development, are released in children.
  • Tissue grows and repairs damage caused by stress and ultraviolet rays.
  • New information is encoded and stored, memories are organized, and problems are solved by our brain.
  • Neurons are “turned off,” allowing for sharper motor skills and reaction time the next day.
  • Sleep reduces blood pressure and heart rate by about 10%, allowing our cardiovascular system to rest.
  • Cellular hormones that help the immune system fight various infections are produced.
  • Blood sugar levels are normalized.
  • Our metabolism rate is reduced and our energy is conserved.

Sleep is as essential to our body and mind as eating or drinking water. Insomnia prevents our body and mind from performing essential tasks. Learn more.

How can I sleep better at night?

Visit our Sleep Tips and Tools section to help you fall asleep and wake up rested.

Who can I contact for more information?
For more information about Unisom® products, please call 1-888-867-7426 or email