Usually a couple weeks. But it you're using it on your face the bottle will last you 6-7 months. Because once you get the look you want the maintenance dose is one pump every day or every other day.
You should look at it like a skin moisturizer. If you stop putting it on your face will get drier.
I used it for the first time and put it on trouble spots....(low back) Works pretty well I think. Might be in my mind because of dieting for so long but I am in better condition now than when I won the michigan and have 13 weeks till Jr. nationals.