Sunday Riley Has Two Versions Of Its Bestseller — & You Might Not Have Noticed

Let's play a little game — name a Sunday Riley product. Now, if you're thinking "Good Genes," then congrats! You've successfully identified one of the brand's top-selling items of all time.

Here's another piece of beauty history you may not have aware of: Back in 2018, Sunday Riley quietly launched a second version of the popular exfoliating treatment, this time with glycolic acid instead of lactic acid – this, in response to then-newly-passed regulation in the European Union that limited the amount of lactic acid that can be formulated into over-the-counter skin-care products.

You may not have even realized that the Good Genes had a fraternal twin, but now, it's front-and-center thanks to an exclusive launch today at Dermstore. "The success of the product in the European market really made us take notice and realize that this is a product that we wanted to offer to our US audience as well," Sunday Riley (the person) exclusively tells Refinery29. "Dermstore has a very skincare-savvy client base that knows and loves Good Genes, and [they] were actively asking about the glycolic version."

As for which one is better for your skin? Well, it depends. Both are forms of alpha-hydroxy acids (AHAs) but can have drastically different effects. "Glycolic acid is a smaller molecule than lactic acid, meaning it can penetrate deeper into the skin," says Riley. "That can make it more aggressive than its gentler sister, lactic acid, but [glycolic acid] also been studied repeatedly for its beneficial properties for acne-prone skin." Additionally, the glycolic version of Good Genes has a slightly higher concentration of acid in it than the lactic version, so that's something to take note of if you've got sensitive skin. (As someone with oily, acne-prone skin that gets easily irritated, I generally prefer the lactic acid formulation. That said, the glycolic one has a very similar creamy texture, but with a more noticeable tingling sensation.)

In terms of pricing, you may remember that Good Genes saw a price decrease of $20 at the beginning of the year, well, the lower pricing will be the same for the glycolic formulation's relaunch as well. "Reducing the price of Good Genes has been a passion of mine for a while," Riley explains. "The $105 price tag for Good Genes was set 10 years ago, and I felt it was outdated and that we could do better for our clients. I wanted to make the pricing as accessible for Europeans as it is in the US."

Too much of a good (genes) thing? Not possible.