Prospan® Menthol is clinically researched to: • Relieve congested coughs • Clear mucus from the airways Prospan® Menthol acts as an expectorant helping to thin and loosen mucus in the chest. Prospan® Menthol helps break up the mucus in the chest and helps it to be expelled. Prospan® Menthol assists in the relief of congested coughs associated with colds or mild bronchitis.