Galactomyces Pure Vitamin C Glow Serum is a lightweight, pale-golden serum that SOME BY MI builds around two headline ingredients: galactomyces ferment filtrate at 75% of the formula, and pure ascorbic acid at 30,000 ppm. It goes on after toner, spreads thin, and sinks in clear rather than sitting on the surface.

Ascorbic acid is the undiluted form of vitamin C, and here it is joined by niacinamide, sodium ascorbyl phosphate and adenosine, plus a long tail of fruit, berry and vegetable extracts. Sodium hyaluronate and panthenol keep the finish comfortable, so a vitamin-heavy formula still feels light. The bottle is amber glass with a pipette, which suits an ingredient this sensitive to light and warmth.

It suits skin that reads flat by the afternoon, feels rough under a cotton pad, or has lost some of its bounce. SOME BY MI recommends the serum for dull and rough skin, and the finish is the point: brighter-looking, smoother, hydrated without any tack. Where most vitamin C serums lead with the acid alone, this one leans just as hard on the ferment.

One honest note before you buy. The formula contains bergamot oil, lavender oil, linalool and limonene, so it is scented and is not a fragrance-free option, whatever some listings imply. It also contains propolis, so it is not vegan. Keep it somewhere cool and dark, and finish the bottle within twelve months of opening.