K-SECRET

The Korean Brand That Pairs Retinal With Fermented Bean

K-SECRET is a Korean anti-aging brand that has carved out a specific lane: retinal-plus-fermented-ingredient formulations at higher concentrations than most K-beauty competitors. The SEOUL 1988 Eye Cream uses 4% retinal liposome plus fermented bean extract. The SEOUL 1988 Cream uses 1% retinal liposome plus fermented rice. These concentrations (4% retinal for eye, 1% retinal for facial cream) are notably aggressive for K-beauty, where retinal concentrations typically sit at 0.05% to 0.5%.

The brand's positioning is "serious anti-aging for informed users." The SEOUL 1988 naming references Korean luxury skincare traditions of that era. The products are targeted at 35+ skin that has built tolerance to retinol or retinal and wants stronger treatments without going to prescription tretinoin. Eye patches variants (caffeine, retinol) add to the anti-aging lineup.

What Makes K-SECRET Different

The retinal concentrations are unusually high for non-prescription skincare. 1% retinal in a facial cream is significantly more aggressive than most retinal products; it delivers faster anti-aging results but requires skin acclimation. The 4% retinal in the Eye Cream is even more concentrated, though retinal penetrates less in eye-area skin due to thinner dermis, so the 4% is more tolerable than it sounds.

The fermented bean and fermented rice pairings are the calming counterparts to the aggressive retinal. Fermented actives (bean, rice, galactomyces) have barrier-supporting and hydrating effects that buffer the irritation potential of high-concentration retinal. This "aggressive active + fermented support" formulation strategy is distinctive to K-SECRET.

Who Should Use K-SECRET

• Mature skin with retinal/retinol tolerance: SEOUL 1988 Eye Cream (4% Retinal + Fermented Bean).
• Serious anti-aging for facial use: SEOUL 1988 Cream (1% Retinal + Fermented Rice).
• Dark circle sufferers: Instant Relief Eye Gel Patches (Caffeine, 60ea).
• Retinol eye patch users: Advanced Regenerating Eye Gel Patches (Retinol, 60ea).
• Additional collagen booster: Collagen Boosting Secret Ampoule.

Our 5 K-SECRET Picks

K-SECRET SEOUL 1988 Eye Cream (4% Retinal + Fermented Bean) 30ml
High-concentration retinal eye cream. 4% retinal liposome plus fermented bean for anti-aging. Use nightly after acclimating (start every other night for first 2 weeks). Targets crow's feet, under-eye fine lines, and firmness.

K-SECRET SEOUL 1988 Cream (1% Retinal + Fermented Rice) 50ml
Aggressive anti-aging facial cream. 1% retinal liposome plus fermented rice for firming, wrinkle reduction, tone evening. For users with established retinol tolerance. Start every other night, build to nightly over 4 weeks.

K-SECRET Instant Relief Eye Gel Patches (Caffeine, 60ea)
Caffeine-based eye gel patches for puffiness and dark circles. Use pre-makeup or twice-weekly for cumulative depuff. 60-patch jar lasts several months.

K-SECRET Advanced Regenerating Eye Gel Patches (Retinol, 60ea)
Retinol eye gel patches for nighttime anti-aging treatment. Combine retinol with peptides in a hydrogel format. Use 2 to 3 times weekly overnight for firming and fine line improvement.

K-SECRET Collagen Boosting Secret Ampoule 50ml
Collagen-plus-peptide ampoule for firming. Use daily AM and PM before moisturizer. Supports the anti-aging effect of the retinal products. Gentle enough for daily use alongside the stronger SEOUL 1988 products.

Frequently Asked Questions

Is 1% retinal safe for daily use?

Retinal is the aldehyde form of retinol, which is less irritating than prescription tretinoin but still potent. 1% retinal is aggressive but within safe commercial range. For established retinol users (who've used 0.3% to 0.5% retinal for 3+ months), stepping up to 1% is generally manageable with standard introduction protocols. For retinol newcomers, this concentration is too aggressive; start with 0.1% or 0.3% retinal first.

4% retinal in eye cream sounds extremely aggressive. Is it safe?

Surprisingly yes, for several reasons. First, retinal is gentler than tretinoin at equivalent concentrations. Second, under-eye skin has thinner dermis and lower absorption rates than facial skin, so 4% retinal in eye cream delivers less effective-concentration than 4% retinal on facial skin. Third, liposome encapsulation slows delivery. Still, introduce slowly: start every 3 days, graduate to every other day, then nightly over 4 to 6 weeks.

K-SECRET vs IOPE Retinol Super Bounce Serum?

Different strengths. IOPE Retinol Super Bounce is beginner-to-intermediate retinol (encapsulated retinol, gentler). K-SECRET SEOUL 1988 is advanced retinal (aldehyde form, more potent). For retinol beginners: IOPE. For established retinol users wanting stronger results: K-SECRET. Don't layer them; choose one based on your current tolerance level.

Is K-SECRET cruelty-free and vegan?

K-SECRET is cruelty-free. The SEOUL 1988 line uses plant-based fermented ingredients (bean, rice) and is vegan-compatible. Some eye patch variants may contain marine ingredients; check individual labels.

Can I use K-SECRET retinal with vitamin C?

Space them out. Retinal is best used at night; vitamin C (especially 10%+ L-ascorbic acid) is best used in the morning. Don't layer them on the same evening; that's too much active layering. Morning vitamin C plus evening K-SECRET is the standard combination.

Where is K-SECRET made?

K-SECRET is formulated and manufactured in South Korea. Mirai Skin sources through authorized Korean distribution.

Do I need prescription tretinoin, or is K-SECRET's 1% retinal enough?

For most anti-aging concerns, K-SECRET's 1% retinal is sufficient over 12+ weeks of consistent use. Prescription tretinoin (0.025% to 0.1% typically) is still more potent per unit but also more irritating. For severe photoaging, cystic acne, or specific medical conditions, consult a dermatologist for prescription options. For cosmetic anti-aging: K-SECRET is a legitimate non-prescription option.

Which K-SECRET product should I start with?

For advanced users ready for aggressive retinal: SEOUL 1988 Cream (1% retinal). For more targeted eye-area treatment: SEOUL 1988 Eye Cream. For less aggressive introduction: the Retinol Eye Gel Patches. Always start with every other night, build tolerance gradually.

Shop K-SECRET at Mirai Skin

Every K-SECRET product at Mirai Skin is sourced directly from authorized Korean distribution. Shop the full K-SECRET collection, or browse related categories: Korean retinol serums, best Korean anti-aging products, and Korean brightening products. Free US shipping on orders over $60.