Feel free to take my word for it—this face serum is the finest skincare item I've ever tried.

      I never imagined I would write this headline. How do you determine the best skincare product you've ever used when, as a beauty director, you're testing hundreds of new beauty products each year? Honestly, I've relied on my journalistic integrity for so long that it's hard to picture a scenario where I'd casually label any product as the best I've ever tried. Yet, here we are. I'm asserting it seriously: Sunday Riley Good Genes Lactic Acid Treatment is the best skincare product I've ever used. Before I delve into what makes the Good Genes Lactic Acid Treatment truly exceptional, I want to clear up some confusion surrounding its history. This product exists somewhere between a face serum and an exfoliating treatment, and it has been celebrated as one of the beloved skincare products among beauty editors for years. The glass-skin effect? Unmatched. The smoothness? Remarkable. The even skin tone? Almost too good to be true. However, in 2018, this product was removed from EU shelves due to regulations concerning allowable strengths of lactic acid. In response, the brand introduced an alternative glycolic acid version of Good Genes (another type of exfoliating AHA that, oddly enough, is arguably stronger than lactic acid but didn’t face similar EU regulation issues). The results were good, but they weren't identical. Now, after nearly seven years, Sunday Riley Good Genes Lactic Acid Treatment is back in the UK. And wow, I have really missed out all these years. After four months of consistent use, here’s what I think everyone should know...

      **The Formula**

      Sunday Riley Good Genes Lactic Acid Treatment

      - **Key ingredients:** Lactic acid, licorice, lemongrass, arnica, aloe, prickly pear extract

      - **How to use:** Apply to cleansed skin at night, two to three times a week (non-reactive skin types may tolerate daily use)

      **Pros**

      - Fast-acting, overnight results after just one application

      - Evens out skin tone

      - Enhances glow

      - Reduces congestion

      - Moisturizes sufficiently without causing dryness

      **Cons**

      - It's a bit pricey

      - Super sensitive skin may not benefit

      Now, let's discuss what Good Genes Lactic Acid Treatment actually does, shall we? This serum-like formula contains a purified form of lactic acid, an alpha-hydroxy acid derived from milk, which exfoliates the skin deeply, improving congestion, texture, dullness, and uneven tone. It works by removing dead skin cells to reveal fresher, more radiant skin beneath. Additionally, unlike other AHAs, lactic acid also has hydrating properties. As a humectant (similar to hyaluronic acid), it attracts water molecules to create a plumping effect in the skin. For me, preferring lactic acid over glycolic acid is essential. Lactic acid's molecules are larger than those of glycolic acid, making lactic generally better tolerated by those with sensitive skin (though patch tests are always advisable, and you should discontinue use if irritation occurs). In addition to lactic acid, the Good Genes Lactic Acid Treatment formula includes skin-brightening licorice, refreshing lemongrass, nourishing aloe, and calming arnica and prickly pear extract.

      **What is promised?** A miracle product that smooths, brightens, evens skin tone, and plumps while minimizing irritation.

      **The Application**

      If you've previously tried a Sunday Riley product, you understand the luxury of it. The bottle is chic, and just one to two pumps is sufficient to cover my face and neck. Its texture is light and lotion-like, gliding over the skin like silk and feeling hydrating as you massage it in. Like all of Sunday Riley’s offerings, the scent is distinct and natural—fresh and pleasant, with a faint medicinal undertone that suggests it’s actively working.

      While the instructions indicate that you can apply this product in the morning or at night, I recommend using it at night due to its acidic nature to avoid any risk of sun damage during the day. With my reactive (but oily and breakout-prone) skin, I initially applied it three times a week, right after cleansing and before moisturizing. Over time, I’ve increased my usage to nearly every evening. Even with my sensitivity to acids, I haven't experienced any irritation.

      For those with very sensitive skin, Sunday Riley suggests using Good Genes as a face mask. Apply one to two pumps all over and leave on for 15 minutes before rinsing off with water.

      **The Verdict**

      Let me emphasize that you'll see and feel results after just one use of Good Genes Lactic Acid Treatment—and that's something I can’t claim for many skincare products. The morning after my very first application, my skin felt baby-soft and looked brighter and more luminous. The results are so impressive that you have to remind yourself not to overapply.

      Having used Sunday Riley Good Genes Lactic Acid