Repurchasing this for the third time (I've also used the 300 strength) and it's truly transformative when it comes to the texture of your skin -- plus, it makes anything you layer on top of it permeate your skin that much more, so it boosts the efficacy of your whole routine. I've used it with retinal, that Biossance lactic acid stuff, vitamin C serums, salmon DNA stuff -- honestly, add this as the first skincare step no matter what you use and reap the benefits. Such a great buy (and for the price, too, as far as skincare stuff goes...). -- Em LTKselfcare LTKOver40 LTKBeauty