The Battle of the Viral Korean Sunscreens: Beauty of Joseon Relief Sun vs Round Lab Birch Juice

Above the Fold – Quick Verdict Box
• Overall Rating: ⭐⭐⭐⭐⭐ (4.9 / 5.0)


• Best For:

◦ Beauty of Joseon: Dry, sensitive, barrier-compromised skin wanting a nourished glow.


◦ Round Lab: Combination, oily, or dehydrated skin craving a weightless water-gel burst.


• Key Ingredients:

◦ Beauty of Joseon: 30% Rice Extract + Grain Ferment Filtrate (Nourishment, skin barrier support).


◦ Round Lab: Birch Sap (Betula Platyphylla Japonica) + Vita Hyaluronic Acid (Intense cellular hydration, cooling).


◦ Both: Modern Chemical Organic Filters (Uvinul A Plus, Uvinul T 150, Tinosorb M, Iscotrizinol).


• Halmae’s Savage Roast:”Is the sun beating down on your face twice today, or is your wallet just itching to throw money at the exact same tube twice?”


• Where to Buy:[Check Best Price on Olive Young Global / Amazon / Stylevana]



1. Storytime: The Unhinged Kitchen Counter Showdown That Started This Review
Listen up, besties, because I was literally on the brink of domestic eviction this morning.

I was standing at our kitchen island, holding my phone with my Olive Young cart open, paralyzed with indecision. In my cart? Both the Beauty of Joseon Relief Sun: Rice + Probiotics and the Round Lab Birch Juice Moisturizing Sunscreen. Everyone on TikTok claims both are the holy grail of glass skin. Naturally, my cosmetic chemist hoarding instincts kicked in, and I figured, why not order two tubes of each?

Enter Malsuk Halmae.

She walks in, brandishing a green plastic flyswatter like a samurai sword, eyeing my open cart with absolute disgust. She smacks the island counter right next to my iced latte and snaps: “Bonghee-ya! Is the sun rising from both the east and the west today? Does sunlight hit your forehead twice? Why are you buying two white creams that do the exact same thing? You have two cheeks, not four!”

I tried to defend myself with science: “Halmae, one uses traditional fermented hanbang grain lipids and the other utilizes Betula sap polysaccharides!”

She didn’t flinch: “All I hear is you trying to spend forty bucks on bean juice and tree water. Pick one before I use this flyswatter to fix your financial judgment.”

Challenge accepted. As a cosmetic chemist, I put both to the ultimate breakdown to figure out which one you actually need.

2. Why Are These Two Breaking the Internet?
Both formulas dominate K-beauty bestseller charts, but their online hype serves two distinct vibes:

• Beauty of Joseon Relief Sun: Driven by the viral Hanbang resurgence and aesthetic TikTok reels chasing an ultra-dewy, lit-from-within porcelain finish—often tied to the coveted Korean actress glow aesthetic.


• Round Lab Birch Juice: Frequently hyped as the “in-flight essential” and off-duty idol secret for surviving dry studio lights, praised for zero white cast and its weightless, water-burst texture.


Both boast SPF 50+ PA++++ broad-spectrum protection verified by independent clinical labs in Korea and Spain, eliminating any sunscreen scandal anxiety.

3. The Chemist Breakdown: Why This Formulation Actually Works
Despite the completely different branding, both sunscreens share a secret: they were manufactured by Korea’s legendary cosmetic lab, Kolmar Korea. They share an identical state-of-the-art chemical UV filter matrix:

• Uvinul A Plus (Diethylamino Hydroxybenzoyl Hexyl Benzoate): High photostability covering the deep UVA spectrum ($320\text{–}400\text{ nm}$).


• Uvinul T 150 (Ethylhexyl Triazone): Exceptionally high absorption coefficient for UVB rays ($290\text{–}320\text{ nm}$).


• Tinosorb M (Methylene Bis-Benzotriazolyl Tetramethylbutylphenol): A hybrid filter that both absorbs and scatters UV rays across both UVA and UVB spectra.


• Iscotrizinol (Diethylhexyl Butamido Triazone): Exceptional water-resistant, oil-soluble UVB protection.


Where the Formulations Diverge
The chemical divergence lies in the solvent carrier and active base:

• Beauty of Joseon suspends these filters in a 30% Rice Bran Water and Lactobacillus/Rice Ferment base. Rice extract is packed with gamma-oryzanol, phytic acid, and amino acids that reinforce the stratum corneum’s intercellular lipid bilayers, locking down Transepidermal Water Loss (TEWL).


• Round Lab relies on Birch Tree Sap (Betula Platyphylla Japonica) combined with multi-depth Hyaluronic Acid. Birch sap is loaded with 17 amino acids, minerals, and natural fructose compounds. It acts as an osmolyte, pulling hydration directly into skin cells without adding heavy, occlusive surface lipids.


4. Real Texture, Sensory Vibe & The “Glass Skin” Finish
• Beauty of Joseon: Feels like a rich, nourishing day cream. It spreads with a velvety slip and dries down into a radiant, emollient sheen. If your skin is dry, flaky, or tight, this feels like an instant barrier hug.


• Round Lab: Dispenses like a soft lotion and instantly bursts into micro-water droplets upon contact with skin temperature. It sinks in within 15 seconds, leaving zero residue, zero tackiness, and a natural, semi-dewy velvet finish.


5. Pros & Cons
Beauty of Joseon Relief Sun
• Pros:

◦ Superb lipid barrier replenishment for dry/winter skin.


◦ Fermented actives soothe irritation and redness.


◦ Acts as a deeply nourishing daily moisturizer (you can skip day cream).


• Cons:

◦ Can feel slightly heavy or greasy on very oily T-zones by 2 PM.


◦ Ferment-sensitive skin types may experience minor fungal acne flare-ups.


Round Lab Birch Juice Sunscreen
• Pros:

◦ Incredibly lightweight water-essence finish; zero pore clogging.


◦ Perfect slip beneath liquid foundations and cushions without pilling.


◦ Fast absorption rate with no sticky residue.


• Cons:

◦ Not rich enough for severe dry skin without a separate heavy moisturizer underneath.


◦ Contains subtle natural aromatic extracts that ultra-reactive skin should patch test.


6. Bonghee’s Pro-Routine: How to Layer for Maximum Absorption
• With Beauty of Joseon: Skip your morning moisturizer! Cleanse, apply a lightweight hydrating toner, and apply two finger lengths of Relief Sun directly. It provides enough occlusive balance to seal moisture while creating a tacky base for makeup.


• With Round Lab: Perfect for your normal 5-step morning routine. Cleanse, tone, apply your antioxidant serum (Vitamin C works wonders here), apply a light gel moisturizer, and slide Round Lab right on top. It will not pill or roll off under cushion foundation.


7. The Final Verdict: Is It Worth Your Hard-Earned Coins?
Halmae was right: you do not need both.

If your skin barrier feels compromised, dry, or you love an ultra-juicy glazed-donut glow, go with Beauty of Joseon. If you have combination, oily, or acne-prone skin that hates heavy layers, grab Round Lab Birch Juice.

K-Beauty Comparison Table

Product Name
Key Active
Best For
Halmae’s Savage Verdict
Link

Beauty of Joseon Relief Sun
30% Rice Extract + Probiotics
Dry, Normal, Sensitive Skin
“Smells like a nice rice cake, keeps your face from looking like dried leather.”
[Olive Young]

Round Lab Birch Juice
Birch Sap + Hyaluronic Acid
Oily, Combo, Dehydrated Skin
“Watery and clean. Good for people whose faces produce enough oil to fry pancakes.”
[Olive Young]

Skin1004 Hyalu-Cica Water-Fit
Centella Asiatica + Hyaluronic Acid
Redness-Prone, Sensitive Skin
“Puts out the fire on your angry cheeks without making you look like a grease trap.”
[Olive Young]



📌 More K-Beauty Insights from Bonghee ♡


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