Benylin Cold & Flu Max Strength Capsules Benylin Cold & Flu Max Strength Capsules relieve the symptoms of cold & flu, including headache, fever, nasal congestion, fatigue, drowsiness & aches & pains. Benylin Cold & Flu Max Strength Capsules contain three active ingredients: Paracetamol: A painkiller that also reduces fever. Caffeine: A stimulant to help combat the tiredness & fatigues associated with colds & flu. It also helps increase the pain relief. Phenylephedrine: A decongestant to relieve nasal congestion.