The first time I tried it myself was about 12 months ago. I’d chased down a bottle when my skin was breaking out and my usual routine wasn’t working. I had high hopes and desperately wanted it to live up to the hype. You see, I have acne-prone skin that easily marks, so it’s promise of brightening and clarifying really sounded like the serum holy grail.

But did the little blue bottle with a big reputation do great things for my skin? Keep reading for a detailed review.

About My Skin: Requires some maintenance

My skin is good when I look after it, but by default it’s prone to congestion, breakouts, uneven tone, pigmentation, and general dullness. I use a lot of exfoliating/brightening/clarifying skincare products (sparingly but regularly) to keep my pores clean, shine at bay, and skin tone bright. I guess you could say that a really good skin-clearing serum or treatment product is the cornerstone of my routine.

The Ingredients: A potent blend

The Is Clinical Active Serum is a potent blend of botanical actives, namely arbutin from mushroom, bilberry, white willow bark, and sugarcane extract. There’s glycerin as well, to provide a little hydration. The serum does contain alcohol denat, an ingredient some skin experts claim as drying (however, the evidence is vague and I personally didn’t find it to be an issue).

The iS Clinical Active Serum is the stuff of skincare legend; a product celebrities use in secret while they’re fronting other brands.

Who It's For: Acne-prone and congested skin

The Active Serum is marketed as a product for both congested/acne-prone skin types and those looking to reduce the appearance of lines and wrinkles. I get why this is (it has superpowers when it comes to resurfacing the skin), but I would definitely advise caution if your skin is dry, thin or sensitized. It’s a highly active product and has quite the tingle, and nobody wants to overdo it, do they?

The Results:

Calm, clear, and bright.

In my experience, the rumors were (and continue to be) true: This really is one of the greatest treatment serums I’ve ever had the pleasure of using. The bilberry and sugarcane really work to exfoliate dead, dull surface cells, whereas the willow bark functions as salicylic acid, unclogging pores and eliminating the severity and frequency of breakouts. The arbutin is a fantastic addition too, as it lightens dark spots, and in my case, reduced the look of post-acne scarring. It feels super fresh, sinks in quickly and gives results in as little as a week, too.

Nowadays, I use the Active Serum two to three nights a week after cleansing and before moisturizer (I cycle it with a vitamin A). The directions state that you can use it daily, but this system has worked really well for me. Overall, I’ve got a calm, clear, bright complexion (most of the time), and I owe some of that to Is Clinical.

This really is one of the greatest treatment serums I’ve ever had the pleasure of using.

The Value:

Consider it an investment

There’s no denying this is an expensive serum, but think of it as a serious treatment product. So if you’re looking to invest and hopefully change your skin, it’s absolutely worth it. You also only need a few drops, so it goes a long way.

Final Verdict:

It really is love

This is a product I’ll always use. It keeps my skin clear, bright and even, not to mention I’ve grown very fond of the menthol-y tingle. It’s not cheap, but considering my complexion isn’t great on its own, this is money well spent.

This is a product I’ll always use.

Words by Emily Algar for Byrdie