Skin1004 Water-Fit Sun Serum Just Hit 23.67 Million Units Sold

The numbers on this one are hard to ignore. Skin1004's Madagascar Centella Hyalu-Cica Water-Fit Sun Serum crossed a cumulative global sales figure of 23.67 million units as of September 30, 2026 — and the pace is accelerating, not plateauing.

The product launched in November 2021, so it's been around for a few years, but 2026 is clearly its breakout year internationally. Sales from January through September this year accounted for roughly 40% of all units ever sold — meaning nearly half the product's entire lifetime volume moved in just nine months. That's not a slow burn; that's a spike.

Summer was the real driver. The May-through-August window — peak sunscreen season — saw sales jump 88.1% compared to the same period last year, and that stretch alone made up about 57% of the year's total January-to-September volume. If you've been seeing this one everywhere on your feed this past summer, the data backs it up.

The US market is a big part of the story. Skin1004 completed the OTC registration process required for sunscreens sold in the US (where SPF products are regulated as over-the-counter drugs), which opened up proper retail access stateside. Across three major global K-beauty platforms — YesStyle, Stylevana, and StyleKorean — US-origin traffic ranked highest among all countries for this product, accounting for roughly 17.9% of total sales across those three platforms combined.

The award wins landed back-to-back in early October. On October 5, the YesStyle Awards 2026 named it No. 1 in the Viral Korean Beauty Product and Favorite Suncare categories. Then during Amazon Prime Big Deal Days (October 6–8), it took the top spot in the Facial Sunscreen category on Amazon.

Formula-wise: it's a serum-texture sunscreen with hyaluronic acid and Madagascar-sourced centella asiatica extract, rated SPF 50+ and PA++++, and the brand states it has completed skin irritation testing. The serum format is part of why it reads differently from a traditional sunscreen — it sits closer to a skincare step than a straight-up SPF layer, which likely explains the crossover appeal beyond dedicated sun-care shoppers.

For anyone building a Seoul shopping list: this is the kind of product that's genuinely cheaper and easier to grab at an Olive Young or local pharmacy than to import. The global sales momentum means it's not a niche find anymore — but the formula hasn't changed, and the SPF credentials are solid for a daily-wear pick.