I have been using this for about 2 months, in combination with Effaclar K. I use Effaclar Duo in the daytime and Effaclar K at night every evening.
For the first 2 weeks I experienced some purging and additional breakouts but after those 2 weeks, my skin looked better than ever. I have noticed a reduction in my post inflammatory hyperpigmentation- flat red marks left after spots. I believe the Duo has had the biggest effect on this as it contains niacinamide which is known to be skin lightening and anti-ageing.
The lotion is light and very easily absorbed. I use it underneath moisturiser and sunblock daily. For very oily skins, this would be fine to use as a moisturiser. I would recommend using spf protection in the daytime when using this as it can increase sensitivity to the sun.
Overall this has been very effective for me in clearing up the acne I have been dealing with since I was 13. I still get the occasional pimple, but find that they go away faster and are less likely to leave any marks.