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Birch Juice (Birch Sap)
By Nur → Last verified 9/26/2026
What it is
Birch juice, or birch sap, is sap tapped from birch trees, used in Korean skincare as a lightweight hydrating base. Round Lab has built an entire product line, spanning cleanser, serum, moisturizer, and sunscreen, around this single ingredient family.
What the evidence says
Commonly included for its hydrating, soothing properties, though it has less independent clinical research than more established actives like niacinamide or hyaluronic acid. Round Lab's birch-based products don't all share one formula: the sunscreen and cleanser both contain fragrance via Anthemis Nobilis (Roman chamomile) flower oil, while the moisturizing cream and serum are confirmed fragrance-free, real, product-specific formula differences worth checking individually rather than assuming the whole line shares one fragrance profile.
Who it's for
Combination skin specifically, Round Lab markets its birch cream as balanced enough to avoid feeling heavy in oilier areas while still hydrating drier ones.
Worth knowing
Fragrance-sensitive skin should check each specific birch-line product individually, since fragrance status genuinely differs within the same line.
Where you'll find it
Products in our catalog that list Birch Juice (Birch Sap) as a key ingredient.
- Anua Birch 70 Moisture Boosting Serum
- ROUND LAB Birch Juice Ampoule
- Round Lab Birch Juice Moisturizing Cleanser
- Round Lab Birch Juice Moisturizing Cream
- Round Lab Birch Juice Moisturizing Mild-Up (UVLock) Sunscreen SPF50+ PA++++ (mineral)
- Round Lab Birch Juice Moisturizing Serum
- ROUND LAB Birch Juice Moisturizing Sun Stick SPF50+ PA++++
- Round Lab Birch Juice Moisturizing Tone-Up Sunscreen SPF50+ PA++++
- Round Lab Birch Juice Moisturizing UV Lock SPF 45 (US version)
Frequently asked
What is birch juice used for in skincare?
It's used as a lightweight hydrating base, commonly included for hydrating, soothing properties, though with less independent clinical research than more established actives like niacinamide.
Is every Round Lab Birch Juice product fragrance-free?
No. The Birch Juice serum and moisturizing cream are confirmed fragrance-free, but the sunscreen and cleanser both contain fragrance via Roman chamomile oil, real formula differences within the same product line.
Which skin type is Round Lab Birch Juice best for?
Combination skin specifically, the moisturizing cream is marketed as balanced enough to avoid feeling heavy in oilier areas while still hydrating drier ones.
Is Round Lab's birch line the same formula across products?
No, each product in the line has its own confirmed ingredient list and fragrance status, worth checking individually rather than assuming uniformity across the line.