Welcome to HCM, I liked the way you put the question. You are very dot specific asking about it. To convince you I will try to answer it very specifically. Here it goes - BEST CURE for SINUS INFECTION -- Amoxycillin + Clavulanic acid combination Now, lot of contradiction will come from other experts if a discussion starts. This answer i put forward is very specific and based on my clinical day to day practice. Few explanation - Sinus infection generally spreads from nose and nasopharynx which are mainly susceptible to penicillin group of antibiotics (Specifically amoxycillin. Clavulanic acid increases effectiveness of amoxycillin). You have asked about sinus infection and NOT Sinusitis (Sinus inflammation) that too about best cure , so I believe best cure for any bacterial infection is antibiotis i.e., eradication of the bacteria and for sinus it is amoxycillin. BUT, infection will accompany inflammation and other supportive treatment like antihistaminic, mucolytic, NSAID, steam inhalation may be needed. I hope i could convince you. Thanks and take care