The number in the brand's name is, of all things, a thermometer reading. Su:m37 was built around the conviction that 37 degrees Celsius, roughly body temperature, is the ideal point for fermenting plant matter into something skin can readily use, and the brand spent years developing a complex it ferments on long cycles before it ever reaches a bottle. Secret Essence is where that entire philosophy lives or dies, because it is the product the whole line, launched in 2014, is organized around. So the fair question is not whether the fermentation story is charming, it plainly is, but whether a sprawling botanical ferment can actually outperform the tidy single-yeast essences that invented this category in the first place.
The ingredient list is, frankly, almost comical to read top to bottom: somewhere north of eighty fermented plant filtrates, from pear juice and barley seed to ginseng, soybean, and a black-tea kombucha ferment, trailed by an entire botanical garden of plant extracts. It is easy to roll your eyes at that maximalism. But the fermentation here is not decorative. The process breaks larger plant molecules into smaller, more bioavailable fragments and generates postbiotic metabolites, amino acids, and organic acids that condition skin in ways the raw extracts cannot, which is the genuine mechanistic logic behind the headline complex. And crucially, the formula does not stop at the plant soup. Sitting high in the list is ferulic acid, pulling antioxidant duty and protecting those fragile fermented actives from oxidizing once the bottle is open. Lower down there is a real hit of niacinamide for tone and barrier support, licorice root for soothing and gentle brightening, and, most interestingly for a first essence, a small trio of ceramide NP, cholesterol, and phospholipids.
That barrier-lipid touch is what makes this essence feel different in practice. Most first essences are watery splashes that vanish on contact and leave nothing behind. This one is silkier, faintly viscous, and it deposits a light conditioned film rather than evaporating entirely. You press a few drops into damp skin after cleansing and it sinks in fast, yet the surface feels cushioned afterward, almost as though a very light serum decided to moonlight as an essence. Skin looks a touch plumper and more radiant right away, which is the immediate and satisfying part, while the niacinamide-and-licorice tone work is the slow build that accrues over four to eight weeks of twice-daily layering. A little spreads remarkably far, so even at 150ml the bottle stretches across months, which softens the per-use cost considerably once you actually live with it. The texture, silky and slightly viscous with a faint slip that sinks in fast, is genuinely one of the nicest in the category, and the way it layers cleanly under serums and creams without pilling or leaving a residue is the kind of detail that justifies the ritual reputation more than the fermentation story does. Skin looks plumper and more radiant, a little goes a long way, and the absorption feels luxurious in a way that is hard to fake, which is why even skeptics tend to concede the experience is pleasant.
Now the honest reservations, because there are two real ones. The first is fragrance. There is no synthetic parfum, but the formula is scented with lavender, bergamot, chamomile, and geranium essential oils, which drag along naturally occurring allergens like linalool, limonene, geraniol, and citral. For most people the herbal-floral scent is genuinely part of the pleasure and a large reason the product reads as a ritual rather than a chore. For reactive, rosacea-prone, or fragrance-sensitive skin, it is a legitimate reason to patch test or to look elsewhere entirely, and it is also why this essence is not fungal-acne safe. The second reservation is the price. This is unambiguously a luxury essence, and you are paying for the brand, the heavy frosted-glass bottle, and the decade-long fermentation narrative layered on top of the actual formula, which is what pulls the value score down despite the quality inside.
What keeps it from feeling like a pure flex is that the formula is, on inspection, actually good. A lot of luxury essences amount to glorified humectant water with a marketing story stapled to the box. This one carries antioxidant protection, a meaningfully dosed brightening active, and barrier lipids that most of its competitors quietly skip, and the supporting cast rests on firmer evidence than the proprietary ferment itself, whose specific clinical claims lean largely on the manufacturer's in-house research rather than independent peer-reviewed trials. It will not transform your skin overnight, and anyone promising that from an essence is selling you something. But as the hydrating, conditioning, radiance-leaning first step in a considered routine, it earns its place on the shelf.
Whether it earns its price is a more personal calculation, and it comes down honestly to how much you value the texture, the scent, and the small daily ceremony of pressing it in. For normal, dry, or combination skin that delights in a luxurious essence step and tolerates fragrance without complaint, it is a genuine pleasure and a sophisticated formula that backs up its theater. For sensitive or fragrance-averse skin, or for anyone who needs the math on a treatment essence to add up to dramatic visible change, the steep price and the essential-oil blend are reason enough to admire it from a distance and choose something plainer.
