1 What is J-Max?

Brand: J-Max

Generic: Guaifenesin and Phenylephrine

J-Max is a drug which is used to relieve cough and nasal congestion. This drug is available as 35mg-1200mg Sustained-Release tablets. This drug is also available in syrup form.


You should read the product information leaflet before using this medication. If you have any questions, ask your doctor or pharmacist.

This medication should be taken by mouth as instructed by your doctor. Do not crush or chew the drug because it may diminish its effects. This medication should be taken with a full glass of water unless your doctor tells you otherwise. You should swallow the drug whole.

Your dosage is based on your medical condition and the way you will respond to treatment. Take this drug regularly to experience the most benefits. You should also take this drug at the same time each day.

If you miss a dose, use it as soon as you remember. Continue to use it as prescribed by your doctor or as stated on the package label.


J-Max may interact with medications such as:

  • Other decongestants taken by mouth or sprayed into the nose
  • Tricyclic antidepressants such as:
  • MAO inhibitors:
  • Blood pressure medications such as:
    • Beta blockers
    • Reserpine
    • Guanethidine
    • Methyldopa
    • or Mecamylamine

Side Effects:

There are no side effects known aside from a possible allergic reaction in people who have previous or unknown hypersensitivity to the drug.

Watch out for signs of allergic reactions such as:

  • Rash
  • Itching
  • Swelling


Before taking this medication, tell your doctor or pharmacist if you have the following: