It was about a day and a half for me. On Friday night I started to feel really congested. I tried ProtectSol a bit that night and because I had a bit of a sore throat I leaned back with the silver sol in the back of my throat as well and then I swallowed. I felt almost instantly better and the next day I did it again in the Saturday morning. But after I went out of the house for about 10 hrs. I didn’t have any with me but I did it again that night. The next morning I felt at least 85% better and the rest seemed to dissipate after that. This is great. I have never taken anything for my cold that has worked so effectively.