The more I've used IGF, the more I see that increasing the dose after several wks, helps me to keep getting a good effect. So I have been using 25-30mcg for 3 wks. Then 50-60mcg for 3 wks. At that point, I can see that it starts to lose effect. If I ever feel that it is losing effect or if I need to stop using it, for instance to travel, I will put my vial in the frezer. It will hold while frozen until I am ready to start back up