Actually, I did this from the Beginning of Jan to the end of March. In April, I began blending equal amts of HQ with the Retin A & smoothing this blend on. It was even more effective that the previous method. Blending the 2 made them highly spreadable. Actually, I was good at making the creams go a long way so I did not go through more than 1 1/2 tubes of each per month! At 15$ per tube, it was downright economical. The more research I did, I began to wonder whether or not much of what I heard about mono 20% were just horror stories & urban legends. I spoke to people who HAD lightened successfully using it. So, approx 3 weeks ago I began using mono 20% on WET skin (to ensure an even spread & avoid blotchiness). In the 1st week, there wasn't anything to report besides dryness. Now, as I begin week 3, I can unequivocally state that it IS beginning to lighten & evenly too. Most of the negative tales you hear are from people mixing HQ with household bleach, lead or mercury. In these cases, it is the additives that are the problem: not the HQ. The same thing happens with mono. People abuse it. Some people even order super high concentrations like 40% hoping for faster results. What they get is disfigurement. Another dumb thing applying it 4-5-6 times per day. If these products are used properly, they lighten well. Since I want dramatic lightening & I want it to be permanent (HQ requires a lifetie maintenance regimen), I switched to mono.