Alka Seltzer XS Alka Seltzer XS provides fast & effective relief from headache with upset stomach. Alka Seltzer XS contains caffeine which helps it act faster to relieve pain including migraine, period pains, toothache, sore throats, neuralgia, lumbago, sciatica, rheumatic & muscular aches & pains, fibrositis & symptoms of cold & flu such as feverishness Ingredients Paracetamol 133 mg, Aspirin (acetylsalicylic acid) 267 mg, Sodium hydrogen carbonate 1.606 g, Citric acid 954 mg, Caffeine 40 mg Directions Over 16 years: 2 tablets dissolved in water every 4 hours as required. Maximum 8 tablets in 24 hours. Not to be used for more than three days except on medical advice. Under 16 years: not recommended except on medical advice.