Vitamin C is one of the most talked-about ingredients in skincare, and for good reason. It's also one of the trickiest to get right. Most vitamin C serums rely on ascorbic acid, which is powerful but notoriously unstable, prone to oxidizing, losing potency, and sometimes irritating skin along the way. We wanted the benefits of vitamin C without asking sensitive skin to tolerate a difficult formula, so we went a different route.

Why we use THD Vitamin C

Our Sun Glow serum is built around a natural, oil-soluble form of vitamin C called THD, a stabilized, slow-releasing variant that keeps working from the first drop to the very last. Unlike ascorbic acid, it doesn't degrade quickly when exposed to air or light, so you get consistent, reliable support every time you use it rather than a serum that loses strength the moment the bottle is opened.

How Vitamin C Forms Compare

What 15% THD Vitamin C can do

At a 15% concentration, paired with upcycled, omega-rich Arctic berry extracts, this formula was built to do real work for skin that wants brightness without compromise:

• Helps protect against everyday stress. Vitamin C is an antioxidant, helping skin defend itself against free radicals from environmental exposure.
• Brightens the look of skin tone. By supporting a more even distribution of pigment, it helps visibly fade the look of dark spots over time.
• Supports skin's resilience. Regular use helps skin look and feel firmer, smoother, and more elastic.
• More stable than L-ascorbic acid. THD Vitamin C holds up far better against air and light, so its benefits don't fade with each use.
• Gentle enough for sensitive skin. The oil-soluble format tends to be far kinder than traditional vitamin C acids.

A vitamin C serum should still be working on the very last drop, which is exactly why we built ours around a stabilized, slow-releasing form instead of the usual unstable acid.

What else is in the bottle

THD vitamin C and Arctic berries don't work alone. Hydrating camelina oil and our wildcrafted Icelandic Botanical Complex round out the formula, helping to soften and nourish skin while the vitamin C does its brightening work. It's a formula built with sensitive skin in mind, gentle enough for daily use but still substantial enough to notice.

Making it part of your ritual

We designed Sun Glow Vitamin-C Serum as a morning ritual, a few drops on clean skin before your moisturizer, so it can help support skin's brightness and resilience throughout the day ahead. Consistency matters more than intensity here. Given time, most people find their skin tone looks more even and their complexion feels a little more awake, without any of the tightness or sensitivity that unstable vitamin C formulas can bring. That, to us, is what a genuinely good vitamin C serum should feel like.

Who it's for

If you've tried vitamin C before and found it stinging, pilling, or losing potency within weeks of opening the bottle, this formula was built with exactly that frustration in mind. It's gentle enough for daily use on sensitive or reactive skin, but still concentrated enough to notice a difference in brightness and evenness over time. Because Sun Glow is designed as a morning step, it fits easily alongside whatever else is already part of your routine, no reformulating your whole shelf required, just one honest, stable dose of brightness each day.

The Research

Vitamin C esters like the 15% THD used in Sun Glow are widely studied for their stability and skin-brightening potential compared to plain ascorbic acid, which oxidizes quickly and can irritate sensitive skin (review, topical vitamin C in dermatology and cosmetics).

Continue Reading

• The Power of Arctic Berries
• Icelandic Wildcrafted Wonders
• Sea Buckthorn: Arctic´s Orange Gold