Isntree vs Round Lab Sunscreen: Same Factory, Same Product? Not Quite
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Ask around in K-beauty circles and you’ll hear it stated as fact: Isntree and Round Lab sunscreens come out of the same factory, so they’re basically the same product. It’s a tidy story. It’s also not what the labels say. Both are hydration-forward Korean daily sunscreens that get recommended constantly, and they do share real DNA. But put the two ingredient lists side by side, as we did, and “twins” falls apart fast. Here’s the honest comparison, and a clear answer to which one belongs in your bag.
TL;DR: Isntree and Round Lab do share a backbone: hyaluronic acid, niacinamide, and two modern UV filters. But they aren’t identical. The Isntree Hyaluronic Acid Watery Sun Gel uses a longer filter list and a watery, weightless gel texture that oily skin tends to prefer, while the Round Lab Birch Juice cream keeps things simple and hydrating, which dry and sensitive skin (and anyone whose eyes sting easily) tends to love. It’s a texture-and-comfort choice, not a performance ranking.
The two contenders
Isntree Hyaluronic Acid Watery Sun Gel (SPF 50+ PA++++). The watery-gel darling, built around a stack of hyaluronic acid forms plus niacinamide, ceramides, and centella. Reviewers reach for it when they want a sunscreen that feels like almost nothing.
Round Lab Birch Juice Moisturizing Sunscreen (SPF 50+ PA++++). The award-winning hydrating cream, led by birch sap, hyaluronic acid, and niacinamide. We reviewed it on its own in our Round Lab Birch Juice review; here it’s playing the comparison game.
Same factory? Read the labels
First, the factory claim itself. Kolmar Korea is known as one of the big contract manufacturers behind a long list of K-beauty sunscreens, and Beauty of Joseon, Round Lab, and Isntree all get named in that conversation. But “made by the same OEM” is not the same as “the same product,” and it’s worth saying the sourcing on the shared-factory rumor is mostly social media and secondhand blogs rather than a primary record. So treat it as industry lore, not a spec sheet, and let the ingredient lists do the talking.
And the ingredient lists tell a clearer story. Here’s what’s actually verifiable on INCIDecoder:
| Isntree Watery Sun Gel | Round Lab Birch Juice | |
|---|---|---|
| UV filters | Six: octisalate, homosalate, Tinosorb S, Tinosorb M, Polysilicone-15, Uvinul A Plus [1] | Two: Uvinul A Plus, Tinosorb S [2] |
| Shared | Uvinul A Plus and Tinosorb S (two modern filters), plus hyaluronic acid and niacinamide [1][2] | |
| Texture | Watery gel | Milky cream |
So the shared DNA is real, two of the same modern filters and the same headline hydrators, which is why people sense a family resemblance. But Isntree layers on four more filters, including Tinosorb M, while Round Lab keeps it to two. That’s not a small footnote: a longer filter list and a gel base versus a two-filter cream are exactly the kind of formula differences you feel on your face. Same family, not the same product.
Where Isntree and Round Lab actually differ
Texture and finish. This is the headline split, and reviewers are consistent about it. The Isntree gel is described as watery and weightless with a near-invisible finish, the kind of thing oily skin likes under makeup. The Round Lab cream is described as hydrating and comfortable with a slightly dewy finish that dry skin loves. Neither is objectively better; they’re aimed at different faces.
White cast. One concrete label difference: Isntree includes Tinosorb M, a filter that works as tiny particles and can read grey on deeper skin tones, which is the exact chemistry we unpacked in our no-white-cast explainer. Round Lab’s two-filter formula skips it. If cast on deeper skin is your dealbreaker, that’s a real, verifiable point of difference, not a vibe.
Eye sting. A recurring note in reviews: some people say the Isntree gel makes their eyes water, while Round Lab tends not to sting. Sensitivity here is very individual, so this is reviewer experience rather than a rule, but if stinging is your history, it’s worth weighing. We went deep on why sunscreens sting in our guide to sunscreens that don’t sting your eyes.
Price. Close enough to ignore. Both sit in a similar mid-range for a Korean daily sunscreen, so cost shouldn’t be the deciding factor here.
So which one should you buy?
Skip the “which is better” framing, because the reviews don’t support a winner. They support a match.
- Choose Isntree if your skin is oily or combination, you want a watery, weightless finish under makeup, and your eyes aren’t easily bothered. It’s the lighter-feeling of the two.
- Choose Round Lab if your skin is dry, normal, or sensitive, you want comfortable hydration over a bare-skin feel, or your eyes sting easily. It’s the gentler, cushier one.
If you’re still not sure which camp you’re in, our oily-skin picks and dry-skin picks sort it by skin type. Ready to buy? The Isntree gel is here, and the Round Lab cream is here.
FAQ
Are Isntree and Round Lab sunscreens the same product?
No. They share two modern UV filters (Uvinul A Plus and Tinosorb S) plus hyaluronic acid and niacinamide, so there’s real overlap, and people often say they come from the same factory. But the labels differ: Isntree’s Watery Sun Gel uses six filters and a watery gel texture, while Round Lab’s Birch Juice cream uses just two filters. Same family, different formulas.
Which is gentler, Isntree or Round Lab?
Reviewers more often describe Round Lab as the comfortable, non-stinging option, which tends to suit sensitive skin and sensitive eyes. Isntree is loved too, but some users report it stings their eyes. Sensitivity is individual, so treat this as a pattern in reviews, not a guarantee.
Which is better for oily skin?
Isntree, usually. Its watery gel texture feels lighter and more matte-leaning under makeup, which oily and combination skin tends to prefer. Round Lab’s hydrating cream can feel too dewy on very oily skin.
Does either one leave a white cast?
Round Lab’s two-filter formula is generally reported as cast-free. Isntree includes Tinosorb M, a filter that can look grey on deeper skin tones, so if cast is a concern for you, that’s the one to test first.
Sources
Ingredient lists (INCIDecoder, verified 2026-07-18):
[1] Isntree Hyaluronic Acid Watery Sun Gel SPF50+ PA++++ (six filters: octisalate, homosalate, Tinosorb S, Tinosorb M, Polysilicone-15, Uvinul A Plus; hyaluronic acid, niacinamide): link
[2] Round Lab Birch Juice Moisturizing Sunscreen, Korean version (two filters: Uvinul A Plus, Tinosorb S; birch sap, hyaluronic acid, niacinamide): link
Korean review cited (open in browser auto-translate):
[3] Naver blog review, Isntree Hyaluronic Acid Watery Sun Gel (self-purchased; the watery-texture card above): link
Note on the shared-factory claim: Kolmar Korea is widely described as a major OEM behind many K-beauty sunscreens, but the specific “same factory, same product” comparison circulates on social media and secondhand blogs rather than a verifiable primary source, so we treat it as industry lore and rely on the ingredient lists above.
