Dm 10guaifenesn 100mg/5ml alc-f sf syrup is a combination medication that typically contains dextromethorphan (DM) as the cough suppressant and guaifenesin as an expectorant. Dextromethorphan helps reduce the urge to cough, while guaifenesin assists in loosening mucus in the airways, making it easier to clear. The "alc-f sf" part likely indicates that the formulation is alcohol-free and sugar-free. Always consult a healthcare professional before using any medication.