I love this product! I have been using this product for almost two years and it is still my holygrail product until now. This is not a harsh exfoliant product but it does its job perfectly. I have struggled with acnes on my early university days and it only got worse each year until I tried this product. Back then I lack on skin care information and products so I can't really explain my skin condition back then, but I remember having to deal with sudden change of weather (from tropical island to a winter weather in sydney) and stress and depression bcs of the new chapter of my life. From then on my face only got worse bcs I did not take care of it properly. This gentle product then helped me with the acnes and breakout and allowed me to try other products on a clearer skin. I used to use this on my morning and night routine back then, but now I use every other day bcs I am also using a retinol product now. And it does not irritate my skin after I use retinol. This is my opinion about this product based on MY EXPERIENCE.

I've used this serum for about a year now, 4-5 times per week in my morning routine (paired with SPF50) to get my dose of AHA and BHA. I have mild rosacea and somewhat sensitive skin that seems to work well with this product. It helps clear up my skin so that I rarely suffer even a single pimple anymore. I only wish that this type of alcohol was not in the ingredient list, but it is in my opinion, the only big flaw of this product. If you want pure AHA or BHA there are products for that, but i this format you get misturizing, soothing and hydrating ingredients as well.

Saw tons of good reviews online...
the promo video is promising but in fact it's a lie..
Useless on my oily and acne prone skin..
makes my acne condition become worse.. more acne and face become red and sensitive..
May be it's just not suit my skin..

I tried this product last month because Youtuber Sunny Dahye recommended this in her 2018 Favorite Skincare video and a lot of blogger hyped this skincare line as well, vigorously, like a cult. Just to let you know that it doesn't live up to the hype AT ALL for me and it is a SCARY product in my experience.

I used this for 3 weeks every day and night.
At the first week, this product really did some magic and dried out my pimples only in the first 2 days of usage. This turned me to a cult in an instant after a week of smooth skin.
But, after the 2nd week, I started get A LOT of breakouts for no apparent reason, especially in the areas which I never had any breakouts at all for my WHOLE life. I thought that maybe it was because of my period or something hormonal. So, I still use this on my 3rd week until I saw a video from another Korean Beauty Youtuber.
She said that this product is simply an exfoliator and very bad for our skin barrier (cough Liah Yoo cough) to my disbelief. cry

Yet, I still cut this out of my skincare routine the next day.
To my relief, my skin has gotten better after 2 weeks. Most of the acne are now gone. Yet, it still leaves me with quite bad fungal acne problem face palm
So I'm still looking at other skincare products to help my skin to get back to its normal & healthy state. Please do your skin a favor NOT to use this serum daily (as recommended by the brand) like I did. When my skin recovered from the fungal acne, I'll be trying this product only as a weekly exfoliator or 2 days SOS product until I found better ones, since I did saw improvement in skin texture and pores. I hope this way, it won't compromise my skin barrier anymore.