Mucinex Image With Text Overlay


Yes, you can safely take Mucinex (guaifenesin) at night. It should not cause any problems sleeping and can help to clear up symptoms of chest congestion and excess mucus.[1]

When To Take Mucinex

Guaifenesin, the active ingredient in Mucinex, is available in both 'extended-release' and 'immediate-release' dosage forms.


Brand name Mucinex products contain guaifenesin in 12-hour extended-release tablets. It is available in two strengths:[2]

  • 600 mg per tablet
  • 1,200 mg per tablet

Mucinex tablets are 'bi-layer'. One layer dissolves and absorbs quickly, for immediate relief, while the other layer dissolves slowly.

Mucinex extended-release tablets can be dosed up to every 12 hours.

There is no specific time consideration as to when you can take Mucinex (as long as you take it as directed). It should be simply taken as needed for symptom control, in the morning, afternoon or evening. The time you take it should not influence its effectiveness or potential side effects.


Guaifenesin is also available in immediate-release tablets, which last four to six hours per dose. Immediate-release guaifenesin is available in two strengths:[3]

  • 200 mg per tablet
  • 400 mg per tablet

These can be dosed every 4 to 6 hours.

Again, just like the extended-release Mucinex products, these can simply be taken as needed, up to six times per day (every four to six hours). You can safely take it at night.

Taking Mucinex At Night

Very often, the concern with taking certain medications at night is the potential for them to cause insomnia, or trouble sleeping.

Fortunately, as it concerns Mucinex, that isn't a known side effect of the medication.

In fact, Mucinex has very few reported side effects and only rarely do they occur. In general, only high doses are associated with serious side effects. Nevertheless, the following have been reported:

  • Nausea
  • Vomiting
  • Drowsiness

There have been rare reports of Mucinex causing kidney stones, but it has only been reported in those taking excessive dosages.[4]

So overall, the side effect profile should have no bearing on whether or not you decide to take it at night or before bedtime.


Mucinex (guaifenesin) can safely be taken at night. It should not cause any trouble falling asleep.

  1. ^ Elsevier ClinicalKey Guaifenesin Monograph. ClinicalKey (Subscription Required)
  2. ^ Mucinex Brand Manufacturer Website.
  3. ^ Role of guaifenesin in the management of chronic bronchitis and upper respiratory tract infections PubMed
  4. ^ Guaifenesin- and ephedrine-induced stones. PubMed