Expectorant

• Mucinex's main ingredient, guaifenisen, is an expectorant that works to thin mucal secretions, making them easier to remove. Because mucus tends to build up in the chest, removal is usually achieved by coughing mucus out of the mouth. Mucinex is available in both regular- and maximum-strength extended-release tablets.
  
  

Cough Suppressant

• Mucinex DM helps relieve chest congestion and cough by combining guaifenisen and dextromethorphan, a cough suppressant. Mucinex DM tablets are extended-release and are available in both regular and maximum strength.
  
  

Decongestant

• Mucinex D combines guaifenisen with pseudoephedrine, a decongestant, to relieve chest, nasal and sinus congestion. It is available in both regular- and maximum-strength extended-release tablets. Mucinex D is available without a prescription, but because it contains pseudoephedrine it must be purchased from behind the pharmacy counter. Depending on state law, you may be required to show identification and provide a signature before purchasing Mucinex D.
  
  

Children's Congestion Relief

• Two forms of Mucinex are also available in children's strengths. Mucinex Mini-Melts are flavored granule packets that combine guaifenisen and dextromethorphan. Children's Mucinex Multi-Symptom Cold is a liquid formula, combining guaifenisen, dextromethorphan and phenylephrine, a decongestant. Mucinex children's products should not be used in children younger than 4.