Ultra-Low Molecular Hyaluronic Acid Serum

This ISNTREE serum offers next-level, deep hydration through a sophisticated blend of 14 hyaluronic acid types, including a unique ultra-low molecular form that penetrates effectively. It’s a clean, vegan Korean skincare essential designed to quench skin from the inside out, delivering visible plumpness and glow with a feather-light feel.

Key Design & Formulation Features

This serum is designed with a focus on ingredient efficacy and gentle performance. Its core feature is a multi-molecular hyaluronic acid complex that targets hydration at different skin depths, supported by a soothing botanical infusion from Ulleung Island. The clean, vegan formulation aligns with a commitment to transparency and skin-compatible care.

Deep, multi-layered hydration

Visibly plumper, smoother skin with lasting moisture

Comprehensive 14-Type Hyaluronic Acid Complex

Formulated with 14 types of hyaluronic acid, from ultra-low to high molecular weight, this serum delivers intense hydration to every skin layer. It helps revive dry, tight, or tired skin, promoting a plump, elastic, and healthy-looking glow without heaviness.

Deep Penetration with Ultra-Low Molecules

The ultra-low molecular hyaluronic acid (329 Da) penetrates deeply, providing long-lasting hydration that traditional serums may not achieve. This helps maintain the skin’s moisture barrier throughout the day, supporting a consistently comfortable and dewy feel.

Lightweight, Fast-Absorbing Texture

Its water-light texture absorbs instantly into the skin without leaving a sticky or greasy residue. This makes it ideal for layering under moisturizer, sunscreen, or makeup, and it’s gentle enough for all skin types, including oily and sensitive skin.

Ideal For

When This Serum Works Best for You

Daily Use

Oily & Combination Skin

Provides deep, non-greasy hydration without clogging pores, helping to balance oil production and leave a matte-but-plump finish under sunscreen and makeup.

Sensitive & Reactive Skin

Gentle Care

Gently replenishes moisture barrier with a clean, vegan formula, soothes tightness, and delivers visible plumpness without irritation or heaviness.

Revive

Dry & Dehydrated Skin

Offers intense, water-like hydration that revives tired, dull skin, restoring a healthy, radiant glow and supporting a resilient, supple complexion.

How to Apply

Simple Daily Application Guide

Incorporate this serum effectively into your daily routine for optimal hydration. Follow these simple steps to ensure the ultra-low molecular hyaluronic acid penetrates deeply and layers smoothly with your other skincare products, maximizing its benefits for a plump, healthy complexion.

Apply to Damp Skin After Toner

After cleansing and using your toner, apply 2-3 drops of the serum onto your fingertips. Dispense the serum onto damp skin to enhance absorption and help the hyaluronic acid draw moisture into the skin more effectively.

Pat Gently for Full Absorption

Gently spread and press the serum evenly across your face and neck using light patting motions. Avoid rubbing. Patting helps the formula absorb fully without tugging, allowing the ultra-low molecules to penetrate deeper for lasting hydration.

Seal with Moisturizer or Cream

Allow the serum to fully absorb for a minute, then follow with your favorite moisturizer, cream, or sunscreen. This seals in the hydration and completes your routine, ensuring the serum’s benefits are locked in for continuous moisture throughout the day.

I absolutely love this serum! The ultra-low molecular formula actually sinks into my skin instead of just sitting on top, and I can feel the hydration immediately. My skin looks plumper and more refreshed, especially in the mornings. It layers perfectly under moisturizer and makeup without pilling, and it's gentle enough for my sensitive skin.

Lightweight and it really does everything it claims. Remember: never apply on dry skin or you are wasting this product! When applied to damp skin, it absorbs perfectly and gives a lasting, comfortable hydration that makes my complexion look healthier and more radiant over time.

Great product and very hydrating, much better than what I was using before. It absorbs really well and my skin feels soft and smooth without any greasy residue. I use it morning and night, and the consistent hydration has made a noticeable difference in my skin's texture.

LOVEE the best serum ever! Super lightweight and is perfect for oily, acne-prone skin. I have seen significant improvements in my skin's hydration level since using it. It doesn't clog pores or cause breakouts, just pure, comfortable moisture that lasts.

This serum gives my face a glow and helps brighten my skin. I love the effect after a few uses; my complexion looks more even and has a healthy dewiness. It's now a staple in my morning routine, and I appreciate how quickly it sinks in.

Real User Experiences

What People Are Saying

Hear from users who have experienced the serum’s hydrating effects firsthand. Reviews highlight its ability to absorb quickly, layer seamlessly, and leave skin feeling plump and refreshed, making it a favored step in many daily routines.

Common Questions Answered

Find answers to common questions about this serum’s texture, skin type compatibility, layering routine, and ingredient transparency. This guide helps you understand how the formula works for your specific needs, from sensitive skin concerns to daily application tips.

What is the texture and feel of this hyaluronic acid serum on the skin?

This serum has a water-light, non-sticky texture that absorbs quickly into the skin. It leaves a smooth, hydrated feeling without any greasy or heavy residue, making it comfortable for daytime use under other products.

Is the Isntree Ultra-Low Molecular Hyaluronic Acid Serum suitable for sensitive skin?

Yes, this serum is formulated to be gentle and is suitable for sensitive skin types. Its clean, vegan formula avoids common irritants, and the inclusion of soothing ingredients like Ulleung Island sea water helps support the skin’s natural barrier.

Which skin types can benefit from using this hyaluronic acid serum?

This serum is suitable for all skin types, including oily, dry, combination, and sensitive skin. Its lightweight formula hydrates without clogging pores or adding excess oil, making it a versatile step for any skincare routine.

Can this serum be layered with other skincare or makeup products?

Absolutely. This serum is designed to be layered. Apply it after toner and before your moisturizer, cream, sunscreen, or makeup. Its fast-absorbing texture ensures it doesn’t pill or interfere with subsequent products.

How often should I apply this hyaluronic acid serum for best results?

For optimal hydration, apply it both morning and evening as part of your regular skincare routine, after cleansing and toning and before moisturizing. Consistent use helps maintain the skin’s moisture balance and support its barrier function.

Does this serum leave any sticky residue or film on the face?

No, this serum does not leave any sticky or greasy residue. Its water-light formula is designed to absorb fully and quickly, leaving the skin feeling smooth, refreshed, and ready for the next step in your routine.

Complete Your Ritual

Explore More Isntree Skincare

Explore more Isntree essentials to complete your clean skincare ritual. Discover complementary products like hydrating toners and lightweight moisturizers that work harmoniously with this serum to build a consistent, effective routine for healthy, radiant skin.

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Isntree Sunscreen

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Isntree Sunscreen Stick

ISNTREE’s Hyaluronic Acid Airy Sun Stick provides quick, easy SPF reapplication with an airy, feather-light texture. Its hypoallergenic formula is enriched with 8 types of Hyaluronic Acid for deep hydration and a plumped-up effect, plus Ceramide for barrier support.

Hero product shot of the Isntree Hyaluronic Acid Watery Sun Gel tube against a soft blue background.

Isntree Hyaluronic Acid Watery Sun Gel

This is more than a sunscreen; it’s a hydrating treatment that protects. By fusing the intense moisture-binding power of hyaluronic acid with advanced broad-spectrum filters, it defends against daily environmental stress while leaving skin feeling soft, dewy, and cared for.

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Isntree Green Tea Toner

The ISNTREE Green Tea Fresh Toner is a quintessential K-Beauty staple, harnessing the antioxidant power of Jeju Island green tea. It uniquely balances effective sebum control with deep, lightweight hydration, making it a must-have for achieving a clear, refreshed, and shine-free complexion without irritation.