The Dewy Edit

Round Lab Birch Juice Moisturizing Sun Serum Review: A Sunscreen That Feels Like Skincare

2 min read

Round Lab made its reputation with the "1025" line — named for the latitude and longitude of the birch forest their key ingredient comes from — built around a simple idea: minimal ingredient lists, pH 5.5 formulas, and nothing that fights the skin barrier. Their sunscreen applies the same logic to SPF, which is a category most brands treat as purely functional rather than as skincare.

What makes it different from a standard sunscreen

Instead of a typical silicone-heavy sunscreen base, this one is built as a "sun serum" — leading with birch sap (Betula Platyphylla Juice) and PDRN, a regenerative ingredient derived from salmon DNA that's become one of the most talked-about actives in recent K-beauty (also showing up in "glass skin" ampoules and post-procedure skincare). The result is a formula that's doing double duty: SPF 50 broad-spectrum protection, plus the hydrating, barrier-supporting ingredients you'd expect from a serum step.

Texture and finish

True to the "serum" naming, it's noticeably thinner and more fluid than most sunscreens — closer to a hydrating essence than a cream. It sinks in fast, leaves no white cast, and doesn't pill under makeup, which is the exact combination that determines whether someone actually reapplies sunscreen or skips it by lunchtime.

Who it's good for

  • Sensitive or reactive skin — Round Lab's whole brand promise is low-irritation, minimal-ingredient formulas
  • Combination to oily skin types that don't want a heavy, occlusive SPF layer
  • Anyone who wants their sunscreen step to also carry hydrating, skin-barrier ingredients instead of being purely protective

Who might want something else

  • Very dry skin in cold climates may still want a richer moisturizer underneath this, since it's a serum-weight formula rather than a cream
  • If you specifically want a mineral (zinc oxide) filter rather than a chemical one, this isn't that — patch test if you're chemical-filter sensitive

Where it fits in the routine

Sunscreen is the final step of a morning routine — step 10 in the full 10-step routine breakdown, applied after moisturizer and before makeup.

Bottom line: if the reason you skip sunscreen is that it feels like a chore layered on top of your actual skincare, this is one of the few formulas that genuinely blurs the line between the two.