Birch Juice Moisturizing UVLock Sunscreen SPF 45
Birch Juice Moisturizing UVLock Sunscreen SPF 45
Product Description
Product overview
Round Lab Birch Juice Moisturizing UVLock SPF 45 is Korea's bestselling chemical sunscreen, reformulated to meet US FDA standards. This lightweight, lotion-like essence-textured sunscreen combines broad-spectrum UVA/UVB protection with deeply hydrating birch sap from Inje's silver birch trees, niacinamide, and hyaluronic acid for a dewy, moisturized finish without white cast.
1,425ppm Birch Juice
Sourced from spring sap of Inje's silver birch trees, rich in amino acids, minerals, and natural moisturizing factors that hydrate and soothe.
Texture & feel
SENSORY1,425ppm Birch Juice
Sourced from spring sap of Inje's silver birch trees, rich in amino acids, minerals, and natural moisturizing factors that hydrate and soothe.
Triple UV Filter System
Avobenzone, Homosalate, and Octisalate combine for broad-spectrum UVA/UVB defense, with PA++++ rating for maximum UVA protection.
Dual Hyaluronic Acid
Sodium Hyaluronate and Hyaluronic Acid attract and retain moisture, leaving skin plump, dewy, and comfortable all day.
Reef-Safe Formula
Free from oxybenzone and octinoxate, making it safer for marine ecosystems while still delivering reliable sun protection.
Safety & compatibility
SAFEFragrance-free, low-irritation tested, and rated "Excellent" by German Dermatest certification.
Non-comedogenic formula with niacinamide; lightweight texture won't clog pores.
Contains Homosalate and Avobenzone (chemical filters under EU review). Many OB/GYNs recommend mineral sunscreens during pregnancy. Consult your doctor.
Contains Polyglyceryl-3 Distearate, Glyceryl Stearate Citrate, Cetearyl Alcohol, and Tocopherol — potential triggers for malassezia-prone skin.
Compatible with retinol, vitamin C, AHAs, and BHAs when used as final daytime step. Always apply sunscreen on top.
Free from oxybenzone and octinoxate, two filters banned in Hawaii and Key West for ocean conservation.
Ingredient breakdown
INGREDIENTSAvobenzone (Butyl Methoxydibenzoylmethane) 2.7%Proven
The global gold standard for UVA protection — the only widely available chemical filter that offers broad UVA1 and UVA2 coverage (310–400 nm), with peak absorption at 360 nm.
- Mechanism: Absorbs UVA radiation and converts it into harmless heat energy.
- Concentration: 2.7% — within FDA-approved limits (max 3%).
- Synergy: Stabilized by Octisalate and Diethylhexyl 2,6-Naphthalate in this formula.
Homosalate 13.5%Proven
An oil-soluble UVB filter that absorbs UV radiation in the 295–315 nm range with peak protection at 306 nm. It also acts as a solvent for hard-to-dissolve filters like avobenzone.
- FDA Status: Approved at concentrations up to 15% in the United States.
- Function: Provides UVB protection and helps boost overall SPF.
- Texture benefit: Improves spreadability and the cosmetic feel of the formula.
Octisalate (Ethylhexyl Salicylate) 4.5%Proven
A UVB filter that absorbs wavelengths from 295–315 nm. Often paired with avobenzone to enhance photostability and water resistance.
- FDA Status: Approved at concentrations up to 5%.
- Photostabilizer: Helps prevent avobenzone breakdown under sun exposure.
- Bonus: Mild emollient properties leave skin feeling smooth.
Birch Tree Sap (Betula Platyphylla Japonica Juice) 1,425ppmPromising
The brand's signature ingredient — harvested in spring from silver birch trees in Inje, Korea. Naturally rich in 17 amino acids, minerals, vitamins, and natural moisturizing factors (NMF) including PCA and hyaluronic acid.
- Anti-inflammatory: Helps soothe redness and irritation in sensitive skin.
- Hydration: Forms a moisture-locking barrier rich in minerals and enzymes.
- Antioxidant: Contains polyphenols that defend against free radicals.
Niacinamide ~2%Proven
Vitamin B3 — a multi-tasking ingredient that strengthens the skin barrier, reduces inflammation, regulates oil production, and brightens uneven skin tone over time.
- Barrier support: Boosts ceramide production for stronger skin function.
- Brightening: Inhibits melanin transfer, reducing dark spots.
- Pore appearance: Helps minimize the look of enlarged pores over time.
Hyaluronic Acid Complex Multi-MWProven
This formula contains both Sodium Hyaluronate and Hyaluronic Acid — different molecular weights that hydrate at multiple skin levels for plump, dewy skin all day.
- Holds water: Each molecule binds up to 1,000x its weight in water.
- Plumping: Smooths the appearance of fine lines temporarily.
- Surface hydration: Higher-MW HA forms a comfortable film on skin.
Soothing Botanicals Blend Mid-Low %Promising
A complex of Artemisia Annua Extract, Anthemis Nobilis (Roman Chamomile) Flower Oil, Portulaca Oleracea (Purslane) Extract, and Allantoin — all chosen for their calming, anti-irritant properties.
- Purslane: Antioxidant-rich; calms redness and inflammation.
- Allantoin: Promotes barrier repair and reduces irritation.
- Chamomile: Traditional skin-soother with anti-inflammatory bisabolol.
Sparassis Crispa Extract & Tocopherol Low %Promising
Cauliflower mushroom extract paired with Vitamin E provides antioxidant defense against free radicals generated by UV exposure and pollution.
- Sparassis: Source of beta-glucans for hydration and immune support.
- Tocopherol: Stabilizes the formula and protects skin lipids from oxidation.
44 ingredients
Active Ingredients: Avobenzone (Butyl Methoxydibenzoylmethane) 2.7%, Homosalate 13.5%, Octisalate (Ethylhexyl Salicylate) 4.5%.
Inactive Ingredients: Water, Butyloctyl Salicylate, Propanediol, Acrylates Copolymer, Butylene Glycol, Caprylyl Methicone, Polyglyceryl-3 Distearate, Benzotriazolyl Dodecyl P-Cresol, Niacinamide, Diethylhexyl 2,6-Naphthalate, Polymethylsilsesquioxane, Glycerin, Calcium Aluminum Borosilicate, 1,2-Hexanediol, Poly C10-30 Alkyl Acrylate, Pentylene Glycol, Cetearyl Alcohol, Tromethamine, Methylpropanediol, Glyceryl Stearate Citrate, Betula Platyphylla Japonica Juice, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Carbomer, Ethylhexylglycerin, Artemisia Annua Extract, Anthemis Nobilis Flower Oil, Sodium Stearoyl Glutamate, Glyceryl Polymethacrylate, Triethoxycaprylylsilane, Pinus Sylvestris Leaf Oil, Sparassis Crispa Extract, Polyether-1, Allantoin, Dipropylene Glycol, Glyceryl Glucoside, Biosaccharide Gum-1, Tocopherol, Portulaca Oleracea Extract, Sodium Hyaluronate, Hyaluronic Acid, Ascorbic Acid.
Where it fits in your routine
ROUTINEAlways the final step in your morning skincare routine, applied before makeup. Reapply every 2 hours during sun exposure for best protection.
How to use
HOW TO USEApply Generously
Use approximately ¼ teaspoon (about 2 finger-lengths) for face and neck. Skimping reduces SPF effectiveness.
Pat & Smooth
Gently spread evenly across face and neck, then pat for absorption. Avoid harsh rubbing to maintain UV filter integrity.
Wait 15 Minutes
Apply at least 15 minutes before sun exposure to allow the chemical filters to bind effectively to skin.
Reapply Every 2 Hours
Reapply after swimming, sweating, or towel-drying. For makeup wearers, use a sunscreen stick or spray for touch-ups.
Who is it for?
WHOPerfect for you if:
- You want hydrating daily SPF that doubles as a moisturizer
- You have sensitive, dry, or normal-to-combination skin
- You hate white cast and want a no-flashback finish for photos
- You wear makeup and need a smooth, non-pilling base
- You want a fragrance-free, dermatologically-tested formula
- You're looking for FDA-approved K-beauty SPF
Consider alternatives if:
- You have malassezia / fungal acne (formula contains triggers)
- You prefer mineral (zinc oxide / titanium dioxide) sunscreens
- You're pregnant and avoiding chemical filters per OB/GYN
- You have very oily skin and want a fully matte finish
- You're sensitive to homosalate or chemical UV filters
- You need SPF 50+ for extended outdoor exposure
Skin type compatibility
SKIN TYPESLightweight essence absorbs quickly without heaviness, but the dewy finish may feel slightly tacky for very oily types.
Birch sap, glycerin, and dual hyaluronic acid deliver real hydration — works as a moisturizer-sunscreen combo.
Balanced formula — hydrates dry zones without overwhelming the T-zone. The natural finish suits mixed skin needs.
Fragrance-free, dermatologically tested, and earned "Excellent" rating from German Dermatest. Patch-test recommended for very reactive skin.
Non-comedogenic with niacinamide. Note: not safe for malassezia-driven (fungal) acne due to fatty alcohols and esters.
UVA protection plus antioxidants (Vitamin E, purslane) defend against photo-aging while hydration plumps fine lines.
Results timeline
2–3 MONTHSHydrated, Dewy Finish
Skin appears plumper, more luminous, and protected. Makeup glides on smoothly without pilling thanks to the lightweight essence texture.
95% noticedComfort & No Irritation
Sensitive skin users typically report no stinging, redness, or breakouts after initial use. Skin feels calm and balanced.
88% noticedImproved Hydration & Tone
Niacinamide and birch sap begin showing benefits — softer texture, more even tone, less visible redness with consistent use.
72% noticedVisible Photo-Protection Benefits
With daily use, expect prevention of new sun damage, less hyperpigmentation, and a more even complexion overall — the long-term payoff of consistent SPF.
65% noticedRatings by platform
19K+ REVIEWSPros & cons
BALANCEDPraised
- Genuinely no white cast on all skin tones
- Lightweight, fast-absorbing essence-like texture
- Works as moisturizer + SPF in one step
- Fragrance-free and Dermatest "Excellent" rated
- FDA-compliant K-beauty (rare combo)
- Layers seamlessly under makeup without pilling
- Reef-safe formula (no oxybenzone or octinoxate)
- Ranked #1 by NBC Select editors among 100+ sunscreens tested
Criticized
- Not fungal acne (malassezia) safe
- Contains 13.5% homosalate (under EU safety review)
- Small 50ml size depletes quickly with proper use
- Slight dewy finish may not suit very oily skin
- Chemical filters may not be ideal during pregnancy
- SPF 45 is below the SPF 50+ many K-beauty fans expect
Budget-friendly alternatives (dupes)
DUPESHigher SPF (50+) at a similar price point. Uses next-gen non-FDA-approved EU filters (DHHB, Ethylhexyl Triazone) for excellent UVA/UVB. More moisturizing, with rice extract instead of birch sap. Note: not sold inside the US through official channels.
Watery serum-like texture similar to Round Lab's essence. Uses centella asiatica (9,800ppm) instead of birch sap for soothing. SPF 50+ with hyaluronic acid; great for sensitive, irritated skin.
Hydration-focused gel with multi-weight hyaluronic acid. Slightly lighter, more matte finish than Round Lab. Higher SPF rating but uses different chemical filters; not FDA-compliant in the US.
Affordable K-beauty alternative with niacinamide and panthenol. Lighter, more matte finish than Round Lab's dewy essence. Uses next-gen filters. Good value for price-conscious shoppers.
Comparison with competitors
SIDE-BY-SIDEStorage & shelf life
12 MONTHS12 months after opening. For maximum SPF efficacy, replace before expiration.
Store in a cool, dry place away from direct sunlight and heat. Avoid temperatures above 25°C / 77°F.
Squeeze tube with screw-on cap. Hygienic and travel-friendly; protects formula from air exposure.
Yes — 50ml tube is well under TSA's 100ml liquid limit, perfect for carry-on luggage.
Frequently asked questions
FAQThis sunscreen contains chemical UV filters — Avobenzone (2.7%), Homosalate (13.5%), and Octisalate (4.5%). While these are FDA-approved at these concentrations, some OB/GYNs recommend mineral (zinc oxide / titanium dioxide) sunscreens during pregnancy and breastfeeding as a precaution, particularly because homosalate is currently under additional safety review by the EU. Always consult your healthcare provider for personalized advice.
No. The formula contains several ingredients known to potentially feed malassezia yeast, including Polyglyceryl-3 Distearate, Glyceryl Stearate Citrate, Cetearyl Alcohol, Tocopherol (Vitamin E), and Anthemis Nobilis Flower Oil. If you have fungal acne or malassezia folliculitis, consider fungal-acne-safe alternatives like Isntree Hyaluronic Acid Watery Sun Gel.
Yes — and it's actually highly recommended. Retinol, AHAs, and BHAs increase skin's sun sensitivity, so daily SPF is essential when using these actives. Apply your actives at night (retinol, AHA, BHA) or in the morning (vitamin C), then layer this sunscreen as the final daytime step. Wait a few minutes between layers for best absorption.
It's most ideal for normal, dry, combination, and sensitive skin types thanks to its hydrating birch sap, dual hyaluronic acid, and fragrance-free formulation. Oily skin users may enjoy the lightweight texture but might find the dewy finish too glowy without a mattifying primer. Mature skin benefits from the antioxidant blend (vitamin E, purslane, sparassis crispa) for anti-aging support.
Hydration and dewy finish are visible immediately after application. Within 1–3 days, sensitive skin users typically experience comfort with no irritation. The longer-term benefits — niacinamide brightening, prevention of new sun damage and hyperpigmentation, more even tone — typically become noticeable after 2–4 weeks of consistent daily use, with full photo-protective benefits over months and years.
Always as the final step of your morning skincare routine, after cleanser, toner, essence, serum, and moisturizer — but before makeup. Apply approximately ¼ teaspoon (2 finger-lengths) to face and neck. Wait at least 15 minutes before sun exposure, and reapply every 2 hours during prolonged outdoor activity, or after swimming, sweating, or towel-drying.
No — its overall comedogenic rating is approximately 1 out of 5. The formula is non-comedogenic and won't clog pores for most users. It includes niacinamide, which actually helps regulate sebum and minimize the look of pores. However, those with malassezia (fungal) acne should choose an alternative due to fatty alcohols and esters in the ingredient list.
The PAO (Period After Opening) is 12 months — indicated by the "12M" symbol on the packaging. For sun protection products, it's especially important not to exceed this date because UV filter efficacy can degrade over time, reducing your actual SPF protection. With proper daily use (¼ teaspoon for face), a 50ml tube typically lasts 1.5–2.5 months, well within the PAO window.
Verdict: Round Lab Birch Juice Moisturizing UVLock SPF 45 is one of the best K-beauty sunscreens available in the US — a rare combination of FDA-compliant filters, fragrance-free formulation, and genuinely lightweight, hydrating, no-white-cast performance. Praised by NBC Select editors and beauty professionals (including Billie Eilish's aesthetician), it's the gold standard for daily wear. Top picks: dry, sensitive, combination, and mature skin types looking for a moisturizer-SPF hybrid. Skip if you have fungal acne or strongly prefer mineral filters.
Product Overview
Quick product notes are a great way to check if a product is free from commonly avoided ingredients by skincare enthusiasts. These preferences come about for different reasons depending on the ingredient such as personal experiences, sensitivities, health preferences & etc.
Just because a product is not free from a common preference does not mean it's a bad product! You can make a personal decision whether or not you want to use a product that contains these ingredients or not - click the labels of the preference to read more about them.
Quick Product Notes
Ever used a product that promised a certain effect but provided no results? It might not have contained any notable ingredients that could have been responsible for that promised effect. It doesn't matter what the marketing or packaging «promises» it can do, if it doesn't contain anything that can help - then the likelihood of it helping is low.
We help you identify key notable ingredients that have been shown to help with effects such as acne-fighting, brightening, UV-protection, wound healing & anti-aging to help you achieve your skincare goals smarter. Please note that different notable ingredients have varying levels of research behind them, some are extremely well proven yet some have mixed research in their efficacy.
Just because a product doesn't contain any notable ingredients doesn't mean it's bad. And a product with notable ingredients (or even many) doesn't necessarily guarantee the efficacy of the product performing these effects either. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine this.
Be smart and use this as just a starting point for you to make more informed and smarter choices and compare it with reviews to see if the product is right for you
Notable Effects & Ingredients
Why are some products great for some people and horrible for others? Well everyone has different skin types and different reactions to the same ingredients.
We've identified a range of ingredients that are commonly regarded as potentially good or bad for those with Dry, Oily/Acne-Prone or Sensitive skin.
A product that contains good or bad ingredients for your skin type doesn't always flat out make the entire product good or bad for your skin. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine your skins reaction.
One of the best ways to use this section is to troubleshoot products you've had bad experiences with in the past. Check if it contains any of the marked ingredients to point out suspect ingredients to avoid in the future!
Ingredients Related to Skin Types
Ingredient Safety Breakdown refers to the percentage % of ingredients in different risk categories as classified by EWG (Environment Working Group) if they are available. There are almost endless cosmetic ingredients and they are one of the few organisations globally that have assigned ratings to a lot of the more commonly used ingredients which is why we reference them.
EWG is seen by many to be more on the alarmist side in their assignment of health ratings resulting in rating ingredients as riskier than they actually are. We recommend using this a reference point rather than a strict guide of ingredient safety and to always do further research if into ingredients that you may find suspect.
Ingredient Safety Breakdown
Product ingredient list
| EWG | CIR | Ingredient Name & Cosmetic Functions | Notes |
|---|---|---|---|
| 2 |
Butyl Methoxydibenzoylmethane
Uv Absorber, Uv Filter
|
UV Protection
|
|
| 0 |
Homosalate
Skin Conditioning, Uv Absorber, Uv Filter
|
|
|
| 4 |
Ethylhexyl Salicylate
Uv Absorber, Uv Filter
|
UV Protection
|
|
| 1 |
Water
Solvent, Skin Conditioning
|
|
|
| 1 |
Butyloctyl Salicylate
Solvent, Skin Conditioning, Hair Conditioning
|
|






