I have EHK and participated in a Tazorac versus Lachydrin study a while back so I'll tell you my experiences with the Tazorac. The Tazorac worked great on my forearms, chest, and inner elbows. However, it had little or no effect on my hands knees(knee caps) or elbows. I was told to apply the Tazorac only after applying eucerin first(don't ask me why). This seemed to inhibit the progress that the Tazorac was/could make. So I mixed them together and applied it that way and it seemed to work fine. I was warned not to apply it full strength though. The Tazorac worked faster then anything I have ever used before, my chest cleared of thick scales in less then 4 days, made my skin baby smooth. I did have one problem, I applied the tazorac to my arm after it had been cleared of scales and it caused my arm to blister like a chemical burn, I didn't think it was a big deal since I heal so fast. Three days later the same spots were still oozing and showed no signs of healing, kinda worried me but eventually they healed. I don't know what strength it was because it was a blind study. I recently visited my dermatologist who conducted the test and he gave me a prescription for Tazorac and Lachydrin and told me to mix them together and apply it that way. I'm not sure if I'm going to try it that way, I can't imagine how painful it would be if I blistered from the tazorac and the lachydrin got into the blister, ouch. I'm still on the fence about using any kind of retinoids anymore, I've had enough problems from the accutane I took. I was also told that there will be an oral Tazorac coming out next year which claims to have very little side effects, yeah right, I'll have to wait and see on that one. If you have any questions for me feel free to write me,