Olbas Max Strength All-in-One Cold & Flu Capsules Olbas Max Strength All-in-One Cold & Flu Capsules relieve the symptoms of colds & flu & the pain & congestion of sinusitis, including aches & pains, headache, blocked nose & sore throat, chills & feverishness (high temperature). They can also loosen stubborn mucus (phlegm) & provide relief from chesty coughs. They contain 3 active ingredients: Paracetamol: a pain reliever that also helps reduce your temperature when you have a fever. Guaifenesin: an expectorant to help loosen phlegm. Phenylephrine: a decongestant to reduce swelling in the passages of the nose to help you breathe more easily.