There is no definite answer to this. Everyone is different, their absorption is different, and the types of isinglass they eat are also different. If you eat it quickly, it will be effective after a few times, but if you eat it slowly for a few months, it will have no effect, because all you eat is cheap isinglass, just like eating vegetables. Isinglass should be older and larger, especially older ones, because the effect of old gelatin is better.