I absolutely love Reedle Shots. The 100 one is a product that has become a staple in my skin care routine and I'll keep purchasing it. I bought 300 Collagen Reedle Shot to try it out since I've grown accustomed to the 100 one. I tried it twice, since 300 one is supposed to be used only every 3 days. So far, for some reason, 300 Collagen Reedle Shot doesn't leave as strong a prickling sensation on my skin as the 100 one. Will wait and see how much it works in the upcoming weeks, and whether I'll repurchase.