This is a great product for my 53 year old skin. I’ve been using it at nighttime for the past two years. There is a definite decrease in facial lines and my skin is so smooth. It tingles slightly when applied but I’ve had no adverse reactions. I highly recommend.

This serum, 15 %, has been great at reducing the enlarged pores on my nose. Helps keep the oil at bay. My skin hasn’t had any difficulties tolerating this strength.
Will definitely purchase again.

I took a chance on this serum and I'm glad I did. It helps with acne and texture. It has a baby sting that is not bad at all and it doesn't make me peel really bad either. Great purchase and will buy again and again.

I use this product to fight sunspots and acne at the same time. If you are trying to choose between the 8% and 15%, start with the 8% first and work your way up because this is a stronger serum. You might experience some mild stinging. The consistency is very fluid, almost like water, but one pump is just the right amount. I like that it’s not heavy because it’s no problem layering my moisturizer on top.

I tried this product because M2 mandelic and malic acid is no longer available. The M2 serum is thicker and makes my skin feel very smooth when I wash my face the next morning but I am giving this product (15%) a solid thumbs up because even if it is thinner, I can at least get the same benefit from the active ingredient.