Benylin Extra Strength Mucus and Phlegm Syrup, 250 mL, works in your lungs to break up mucus and phlegm, and help clear it from your chest. This extra strength, fast-acting formula loosens and thins out mucus and phlegm so that you can expel it when you cough. Get fast, effective relief of mucus an phlegm, and chest congestion. Each 5 mL or 1 teaspoonful (tsp.) contains 200 mg of expectorant Guaifenesin to thin and loosen phlegm and mucus and 15 mg of analgesic Menthol to relieve sore throat pain. To use, Adults and children 12 years and older, take 2 tsp. (10 mL) every 6 hours as needed. Do not exceed a total of 8 tsp. (40 mL) per day. Available in a bottle of 100 mL and 250 mL. Be unshakeable with Benylin.To use, Adults and children 12 years and older, take 2 tsp (10 mL) every 6 hours as needed Do not exceed a total of 8 tsp. (40 mL) per day. Each 5 mL or 1 teaspoonful (tsp) contains 200 mg of expectorant Guaifenesin to thin and loosen phlegm and mucus and 15 mg of analgesic Menthol to relieve sore throat pain. Get fast, effective relief of mucus an phlegm, and chest congestion. This extra strength, fast-acting formula loosens and thins out mucus and phlegm so that you can expel it when you cough. Benylin Extra Strength Mucus and Phlegm Syrup, 250 mL, works in your lungs to break up mucus and phlegm, and help clear it from your chest.