Spinoffs, when done correctly, can often end up even bigger and better than the original—just look at a little show called The Simpsons for all the evidence you need. In the beauty world, product spinoffs are a bit fewer and further between. It’s not uncommon to see a brand build out a themed collection based on the reception of a few items, but a true spinoff that builds on the original’s success with plenty of its own weight-holding features? That’s a feat—and one Tower 28 just nailed with ease.
If you’re even a passing fan of the Gen Z-beloved brand that counts celebs like Khloe Kardashian and Mandy Moore as admirers, you’ve almost certainly heard of its SOS Daily Rescue Facial Spray ($28). As the brand’s most repurchased product, it utilizes hypochlorous acid (a natural body-produced antibacterial and anti-inflammatory) to keep skin soothed, smooth, and stress-free. Tower 28’s newest product, the SOS Intensive Rescue Serum ($34), takes that same principle (and hero ingredients) and spins it into a daily serum that doubles down on combating irritation and acne—just in time for those sweaty, sunscreen-heavy days. The SOS Serum is, essentially, a summer skin life raft.
The new SOS Intensive Rescue Serum is at once lightweight and seriously effective. Formulated to eliminate irritation and inflammation (like acne, for example), and strengthen the skin barrier to promote even more healing, the serum immediately neutralizes redness and relieves visible irritation, too, offering both instant and compounded benefits over time.
Tower 28 founder Amy Liu explains that the serum was conceived as a way to deliver the same skin-saving effects as the original SOS in a longer-lasting, more concentrated way. "Our SOS Intensive Rescue Serum delivers hypochlorous acid in a serum format which allows it to work harder and longer," Liu tells Byrdie. "It’s a super lightweight, water-based serum that purifies your skin and gently cleanses your pores—perfect for those who suffer from acne, blemishes, eczema, rosacea, and psoriasis."
Unlike many best-selling serums, the SOS Intensive Rescue is comprised of just four ingredients: Water, sodium magnesium fluorosilicate, sodium chloride, and that all-important hypochlorous acid. You already know water and sodium chloride (salt). Sodium magnesium fluorosilicate is simply a mineral-based emulsifier. However, hypochlorous acid is the undisputed star of the show here, though (like all true stars), it can be tricky to work with.
"Hypochlorous acid is a finicky ingredient and notoriously difficult to stabilize," Liu says, adding that she even hired specialized chemists to crack the formula. "We went through so many iterations to make sure it would work (keep skin calm and clear), play well with makeup, and have a nice dry down." To put the then-unveiled product through its paces, Liu says Tower 28 even enlisted the help of celebrity makeup artists and estheticians like Katie Jane Hughes and Sofie Pavitt.
But it's not just the beauty industry that's loving the formula. Some doctors are even recommending the brand's SOS line to patients dealing with more serious, chronic skin conditions and for post-op healing. "SOS has become a favorite among medical professionals because it's a stable form of hypochlorous acid in a gentle formula that is cost-effective as well as easy to obtain," explains Dr. Kelly Killeen, a double board-certified plastic surgeon at Cassileth Plastic Surgery. "I mean, it's at Sephora, can you get easier than that?"
How To Use It
Thanks to its supercharged hero ingredient and simple formula, the serum is a solid pick for virtually all skin types, though some may appreciate the effects more than others. "Anyone with chronic inflammation or irritation to their skin benefits from this serum," Dr. Killeen says. "Examples would be acne, rosacea, sensitive skin, recently injured with sunburn or procedures, or melasma." But as Liu adds, both SOS products are formulated to suit many other skin scenarios, too, thanks in large part to how well the serum pairs with existing actives in your routine (think: retinol, exfoliant, or vitamin C products).
"It’s actually a great buffer for those who experience sensitivities from harsher ingredients," she says. Personally, Liu likes to apply it after cleanser, using the SOS Spray as a toner and patting 2-3 drops into her skin each morning before moisturizer and sunscreen. She uses it again in the evening, layering it with a thicker, rich moisturizer. "It instantly soothes my skin and its purifying benefits work as a gentle exfoliator, allowing other skincare products to absorb even better without any irritation," she says.
With the sun at its strongest, sweat flowing, products piled on, and chlorine everywhere, this simply-formulated skin saver arrives just in time.