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Unisom for Insomnia: Uses, Dosage, Side Effects

Unisom sleep tabs
Written by:

Rabia Khaliq

MSc in Applied Psychology


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The medications listed on this website are provided for informational purposes only. Their inclusion does not guarantee that they will be prescribed to any individual, as treatment decisions are ultimately at the discretion of healthcare providers. This list is not exhaustive, and healthcare providers may prescribe other medications, including non-stimulant options, based on the patient’s unique health circumstances and needs. Read more

Unisom is an over-the-counter medication for promoting sleep in adults with insomnia. Unlike other sleep aids such as Ambien, Unisom isn’t habit-forming. Therefore, you don’t require a prescription to obtain this pill. However, you should talk to your doctor before trying this medication for sleep problems. Below, let’s review the reason for that and learn more about Unisom sleep tabs, including dosage, interactions, and side effects.

Untreated insomnia can affect both mental and physical health. Start treatment today.

What is Unisom?

Unisom, the brand name of doxylamine, is a drug belonging to the antihistamine class of medications. The active ingredient, doxylamine succinate, blocks the effects of histamine, a natural body chemical responsible for allergic reactions and other symptoms such as:

  • Itchiness
  • Nasal congestion
  • Watery eyes
  • Runny nose
  • Sneezing

Thus, Unisom alleviates night colds and allergic reactions. Individuals with trouble sleeping can also use this medication and fall asleep faster as it induces drowsiness. The medication blocks histamine receptors in the central nervous system, which prevents neuron stimulation, causes a sedative effect, and thus makes you sleepy.

Although Unisom can be bought without a prescription, this doesn’t mean it lacks side effects. Before taking the sleeping pill, consult a doctor and learn the potential risks. Also, you should not take Unisom (doxylamine) for insomnia for more than two weeks.

Unisom Dosage

Unisom sleep aid is available in 25-milligram tablets. When used as a sleeping aid, the recommended daily dose is 25 to 50 mg, taken by mouth at least 30 minutes before bed. However, if the 25 mg tablet makes you excessively drowsy, reduce the dose to 12.5 mg daily.

The sedative effects of Unisom begin around 30 minutes after swallowing the pill and last up to 6 hours. Thus, ensure you have a full night’s sleep after taking the tablet.

The Duration of Treatment

Unisom is a temporary sleep aid and should not be used for more than two weeks. While Unisom is non-habit forming, you can develop tolerance when you take it for extended periods. Tolerance implies you will have to take higher doses to achieve the same effect, increasing the risk of side effects. If your sleep problems persist after taking the tablets for two weeks, contact a sleep hygienist or healthcare provider.

Consult a doctor to know what dosage of Unisom will help you best.

Unisom Side Effects

Every medication has potential side effects and unwanted responses that occur despite taking the drug in the recommended doses. That said, not everyone experiences these undesired effects, and the severity often varies. Most side effects are mild and disappear as your body gets used to the medication.

Common side effects of Unisom include:

  • drowsiness
  • dizziness
  • headache
  • poor coordination
  • fatigue
  • dry mouth
  • confusion
  • vision changes, including blurring
  • stomach pain
  • constipation
  • difficulty urinating

Other Unisom side effects are potentially dangerous and require immediate medical intervention. For example:

  • Anaphylaxis (severe allergic reaction), characterized by difficulty breathing, skin rash, and hives.
  • Blood cell disorders such as agranulocytosis.
  • Hallucinations.
  • Delirium.

If you develop any severe side effects when taking Unisom for insomnia, contact your doctor or emergency department immediately.

Discuss your symptoms and health history with MEDvidi doctors to get a personalized treatment plan.

Unisom side effects

Precautions and Warnings

Only adults and children above 12 years can use Unisom for insomnia. The safety and efficacy of this sleeping aid in individuals below 12 are unknown. Also, it should not be used with alcohol due to the potential excessive sedation risk.

If breastfeeding mothers occasionally take small doses of Unisom, it might not affect their babies. But large doses of Unisom taken for prolonged periods might cause drowsiness, colicky symptoms, and irritability in breastfed infants.

Unisom can worsen or precipitate certain medical conditions, including glaucoma, hyperthyroidism, asthma, bladder obstruction, and COPD. The list of potential drug-drug or drug-disease interactions is long. Therefore, before taking Unisom, consult a healthcare provider to reduce the risk of potential adverse reactions.


The efficacy of Unisom tablets in treating insomnia is lower than prescription sleep medications like Ambien and Xanax. Do not consider Unisom as your first-choice medication if you have chronic insomnia. If you have trouble falling asleep or maintaining sleep, consult MEDvidi doctors to get suitable medication prescribed.

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Written by:

Rabia Khaliq

MSc in Applied Psychology


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