Freckles: Retin A with Obagi nu Derm blender?

You should use both. Clear is applied in daytime, Blender applied at nighttime. I would also recommend laser or TCA peels for the freckles if improvement is not seen after 3- 6 months using just the creams. Make sure you are always wearing a sunblock as well when using these creams.

Usually a combination approach is needed to improve freckles. I recommend a combination of laser devices, IPL combined with Fraxel, as well as TCA peels that give great results. I would recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer

If you are trying to lighten freckles, the NuDerm line will be the most effective with Tretinoin.  Obagi recommends that you use the strongest Tretinoin that you can tolerate for maximum skin cell turnover.  Usually it takes a couple months in order for your skin to normalize after any change in skin care regimen. 

The Obagi Nu-Derm System is just that, a system. It is designed to be used together. Very good studies have shown that when used in that way the results are 2-3 times better than using the individual products. This means you need the cleanser, toner, Clear, Exfoderm, Retin-A, Blender, probably Sunfader for 3 months and the zinc oxide sun block. You should also be overseen by a physician who is experienced in skin rejuvenation.