Compare Unisom vs. Robitussin

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Unisom Sleeptabs
(doxylamine)

Robitussin
(guaifenesin)

Treats allergy symptoms and helps you sleep. Unisom Sleeptabs (Doxylamine) can help you get a good night's sleep, but you can have a hard time waking up if you don't give yourself enough time to sleep.Breaks up mucus that causes cough. Robitussin (Guaifenesin) is a useful medicine for loosening congestion in your chest and throat, but it doesn't last as long as other guaifenesin products.
Reviews & ratings
Filter group. All currently selected
Filter group. All currently selected
4.45Unisom
Reviews for Unisom
58%
of people (All ages) say Unisom is worth it
32%
say it works well
11%
say it's a big hassle
585 reviews
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Have you used Robitussin (guaifenesin)?
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Side effects
UnisomRobitussin

We haven’t found good data for Unisom side effects.

FDA side effect reports for Unisom »

We haven’t found good data for Robitussin side effects.

FDA side effect reports for Robitussin »
How it works
UnisomRobitussin
Unisom Sleeptabs (Doxylamine) is an antihistamine. It blocks histamine, a chemical that causes congestion, itching, and other allergic reactions. It also makes you sleepy.Robitussin (Guaifenesin) is an expectorant. It contains guaifenesin, which thins and loosens mucus, making it easier to cough out.
Type of medication
UnisomRobitussin
Prescription or OTCOver-the-counter
Available as
UnisomRobitussin
  • Pill
  • Chewable tablet
  • Liquid
  • Liquid
Used for
UnisomRobitussin
Risk factors for serious side effects
UnisomRobitussin
  • Using other drugs with similar ingredients
  • Age 65 years or older
  • Taking with alcohol
  • Taking other medicines that make you less alert
  • Children age 6 years or younger
Detailed Unisom Sleeptabs (doxylamine) risks & warnings »
    Detailed Robitussin (guaifenesin) risks & warnings »
    Pregnancy

    The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

    The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

    Alcohol
    UnisomRobitussin
    • Don't take it with alcohol or other drugs that make you sleepy.
    • Drinking alcohol while taking Unisom Sleeptabs (Doxylamine) isn't recommended.
    No alcohol related info.
    Sleep
    UnisomRobitussin
    • Not habit-forming like other sleep aids can be.
    No sleep related info.
    Upsides and benefits
    UnisomRobitussin
    • Works well to help you fall asleep and doesn't make you feel groggy the next morning.
    • Has fewer side effects than prescription sleep aid medications.
    • Available over the counter without a prescription.
    • Not habit-forming like other sleep aids can be.
    • Robitussin (Guaifenesin) reduces the thickness and amount of mucus in your throat and chest.
    • It’s available at the drugstore either by itself or in combination with other medications to treat cold and flu symptoms.
    • Available in multiple forms.
    • Can be used in children 12 years and older.
    Downsides and risks
    UnisomRobitussin
    • Shouldn't be used unless you have a full night to sleep.
    • You shouldn't drive after taking Unisom Sleeptabs (Doxylamine) until you know how it affects you.
    • Drinking alcohol while taking Unisom Sleeptabs (Doxylamine) isn't recommended.
    • It can increase the risk of falls, so elderly people shouldn't use Unisom Sleeptabs (Doxylamine).
    • Robitussin (Guaifenesin) doesn't last as long as other products that contain guaifenesin. Mucinex's extended release form lasts 12 hours and Robitussin (Guaifenesin)'s lasts 8 hours.
    • You need to drink a lot of fluids while taking this medication or it won't work as well.
    • Robitussin (Guaifenesin) isn’t useful if you have a dry cough.
    • Can cause nausea, headache, and an upset stomach.
    Tips from our pharmacists for people taking the medication
    UnisomRobitussin
    • Starts working in 30 minutes.
    • Unisom Sleeptabs (Doxylamine) makes you tired, so take it before you go to sleep.
    • Don't take it with alcohol or other drugs that make you sleepy.
    • If you need to use it for more than a few weeks, talk with your doctor. A different medication might work better for you long-term.
    • Unisom comes in two different generic forms, doxylamine (Unisom SleepTabs) and diphenhydramine (other Unisom products). Both are antihistamines that help you sleep.
    • Drink plenty of fluids while taking Robitussin (Guaifenesin) because liquid helps break down mucus.
    • Steam from a humidifier, cool mist vaporizer, or hot shower can also help add moisture to your airways.
    • Follow age-specific dosing instructions on how much to take.
    • If your cough lasts more than 7 days, call your doctor.
    • Robitussin (Guaifenesin) only works for coughs with mucus, so don't use it if you have a dry cough.
    Learn more
    More about UnisomSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Unisom Sleeptabs (doxylamine)?
    Worth itNot sureNot worth it
    More about RobitussinSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Robitussin (guaifenesin)?
    Worth itNot sureNot worth it