Kiehl'sUltra Pure High-Potency 9.8% Glycolic Acid Serum, Concentrated Face Serum to Exfoliate for Glowy Skin, Visibly Smooths Skin Texture & Boosts Skin Glow, All Skin Types, Fragrance-free - 1 fl oz

Really does the trick to the skin as it is used with 2 other skin regiments in the morning and my skin Les smoother and firmer

I ordered this because of the great reviews, but also because after research, found it had a relatively low PH so I figured it would be stronger. But..the best part - it sinks into the skin quickly - and is not sticky at all. So far - I am loving it.

Fast shipping. Delivery was great. Started using it but only 3 days in. My skin feels great so far. No adverse reactions. I’ll update as use goes on!

Makes my skin feel buttery soft. Good value for the size, shipped quickly will buy again.

Love this. Works great! Skin softness

This 9.8% glycolic acid serum from Kiehl's is not for the weak or the sensitive-skinned. It's a very potent formulation and features a high concentration of chemical exfoliant to make your skin glow and look nice and glassy. It can sting and even burn if used correctly or absolutely ruin your skin barrier. Do NOT use this with any other actives such as vitamin C or retinoids unless you want to have a very bad time. :) Also if you have angry red mountains on your skin, don't use this unless you want them to turn into volcanoes. Use only on unbroken skin.I am not sensitive at all and it stung when applying. I followed up with hyaluronic aid and a thick moisturiser before bedtime to seal in the ingredients. After a week, my skin does look much more radiant and my pores look much smaller so I'm very pleased with the results. If you have to use this in the day, please wear sunscreen! The formulation was fragrance-free and vegan so there is a lot to love about how this is formulated.I think as long as you're careful, this exfoliating serum will work wonders for those trying to achieve the glass skin effect. But if you are sensitive by any means or have broken skin, please don't use this. It's not suitable and the packaging should be updated to reflect how strong this really is. It can melt your face off if you're not careful!

Great product will purchase again!

I'm really happy with this glycolic acid serum. Kiehl's has always been a well-known trusted brand to me when it comes to skincare, so I was very excited to try this product. It arrived well secured with no risk of leakage, and for a 1oz package, a little went a very long way, lasting me for months as long as you're not wasteful in your application. To use, you apply 2 to 3 drops to your face before bed to your cleansed face. I used these on where my skin pores are most prominent; one drop on both sides of the area an inch below my eyes, and one on my nose, then I would rub it in evenly. In the morning, you cleanse your face again, as glycolic acid can make your skin more sensitive to the sun's UV, so it is best to only apply overnight. I never had any adverse reactions while using this product, and felt I could see visible results in the size of my pores as well as the glow and tightness of my face. I am very happy with this product, and I would definitely recommend it to others!