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Ultra-Low Molecular Hyaluronic Acid Serum

Ultra-Low Molecular Hyaluronic Acid Serum

Product Description

Product overview

Made in Various INTERNATIONAL

A lightweight, fast-absorbing vegan serum featuring 14 types of hyaluronic acid with an ultra-low molecular weight of 329 Da for deep penetration. Infused with mineral-rich deep seawater from Ulleung Island, Korea, this fragrance-free formula delivers intense, long-lasting hydration while soothing and strengthening the skin barrier.

Vegan Cruelty-Free Fragrance-Free Alcohol-Free Fungal Acne Safe 14 Types of HA Clinically Tested Reef Safe
Pregnancy
Yes
Fungal Acne
Yes
Comedogenic
0/5
Size
50ml / 1.69 fl oz
HA Types
14 Molecular Weights
Lowest MW
329 Da
Key Source
Ulleung Island Sea Water
Finish
Dewy, Non-Sticky
Real reviews · YouTube Shorts
Why it's different

14-Layer Hyaluronic Acid Complex

Multiple molecular weights (329 Da to 2,000 kDa) penetrate different skin layers for comprehensive hydration from surface to deep dermis.

01

Texture & feel

SENSORY
Consistency
Watery Gel
Scent
Fragrance-Free
Absorption
3 Seconds
Finish
Dewy

14-Layer Hyaluronic Acid Complex

Multiple molecular weights (329 Da to 2,000 kDa) penetrate different skin layers for comprehensive hydration from surface to deep dermis.

Ulleung Island Deep Sea Water

Rich in magnesium, calcium, and potassium minerals that help retain moisture, strengthen skin defenses, and prevent dehydration.

Glyceryl Glucoside Technology

Activates aquaporin water channels in skin cells to deliver moisture more efficiently and maintain hydration for up to 24 hours.

Soothing Botanical Complex

Madecassoside, Beta-Glucan, Panthenol, and Allantoin work together to calm irritation, reduce redness, and strengthen the skin barrier.

02

Safety & compatibility

SAFE
Pregnancy & Breastfeeding Safe

Free from retinoids, salicylic acid, hydroquinone, and chemical sunscreens. All ingredients are considered safe for use during pregnancy and nursing.

Fungal Acne (Malassezia) Safe

Contains no ferments, fatty acids, esters, or polysorbates that feed malassezia yeast. Verified safe by multiple ingredient checkers.

Non-Comedogenic (Rating: 0/5)

Lightweight, water-based formula with no pore-clogging oils or heavy emollients. Safe for acne-prone and sensitive skin types.

Hypoallergenic Formula

Clinically tested with a 0.00 hypoallergenic index. Free from artificial fragrances, dyes, parabens, sulfates, and common allergens.

Ingredient Compatibility

Pairs well with all active ingredients including retinol, vitamin C, AHAs, BHAs, and niacinamide. Use on damp skin for best absorption.

100% Vegan & Cruelty-Free

No animal-derived ingredients. Never tested on animals. Isntree is verified cruelty-free by Cruelty-Free Kitty.

03

Ingredient breakdown

INGREDIENTS

14-Type Hyaluronic Acid Complex Multi-WeightProven

The star of this formula featuring hyaluronic acid at various molecular weights from ultra-low (329 Da) to high (2,000 kDa). Each size serves a different purpose - smaller molecules penetrate deeply while larger ones form a protective moisture barrier on the surface.

  • 329 Da Ultra-Low MW: Penetrates deep into the dermis for inner hydration
  • 5 kDa Low MW: Provides dense, deep-layer moisture
  • 80 kDa Low MW: Delivers targeted deep hydration
  • 500 kDa Medium MW: Balances surface and inner skin moisture
  • 2,000 kDa High MW: Forms protective moisture barrier on skin surface
Includes specialty HA derivatives: Sodium Acetylated Hyaluronate (better skin adhesion), Hydroxypropyltrimonium Hyaluronate (cationic for better binding), and Sodium Hyaluronate Crosspolymer (5x water-binding capacity).

Ulleung Island Deep Sea Water Primary BaseProven

Mineral-rich deep seawater sourced from Ulleung Island, South Korea. Contains naturally occurring magnesium, calcium, and potassium that help maintain skin's moisture balance and support the skin barrier.

  • Magnesium: Helps combat acne and skin infections
  • Calcium: Supports skin barrier repair and cell renewal
  • Potassium: Maintains skin hydration and elasticity

Glyceryl Glucoside 0.15-0.60%Proven

A sugar-based moisturizing compound that activates aquaporin water channels in skin cells, enhancing the skin's natural ability to transport and retain moisture at the cellular level.

  • Research: Stimulates aquaporin-3 expression for improved water transport
  • Benefit: Long-lasting hydration that works from within the cells

MadecassosideProven

One of the four active compounds from Centella Asiatica (Cica), known for its powerful soothing, wound-healing, and antioxidant properties. Helps calm irritated skin and supports barrier repair.

  • Anti-inflammatory: Reduces redness and irritation
  • Wound healing: Promotes skin repair and recovery
  • Antioxidant: Protects against environmental stressors

Beta-GlucanProven

A polysaccharide known for its exceptional moisture-binding and barrier-strengthening properties. Helps soothe sensitive skin and protect against environmental damage.

  • Hydration: Penetrates deeply to provide lasting moisture
  • Barrier support: Strengthens the skin's protective function
  • Soothing: Calms reactive and sensitive skin

Panthenol (Pro-Vitamin B5) 0.35-0.75%Proven

A humectant and emollient that attracts moisture to the skin and helps maintain softness. Converts to Vitamin B5 in the skin to support healing and reduce inflammation.

  • Moisturizing: Attracts and binds water to the skin
  • Healing: Supports wound healing and skin recovery
  • Anti-inflammatory: Helps calm irritation and redness

34 ingredients

Sea Water, Water, Methylpropanediol, Glycerin, Butylene Glycol, 1,2-Hexanediol, Betaine, Pentylene Glycol, Carbomer, Caprylyl Glycol, Allantoin, Tromethamine, Ethylhexylglycerin, Xanthan Gum, Panthenol, Malachite Extract, Hydrolyzed Hyaluronic Acid, Disodium EDTA, Glyceryl Acrylate/Acrylic Acid Copolymer, Glyceryl Glucoside, Sodium Hyaluronate, Potassium Hyaluronate, Hyaluronic Acid, Hydrolyzed Sodium Hyaluronate, Sodium Acetylated Hyaluronate, Hydroxypropyltrimonium Hyaluronate, Sodium Hyaluronate Crosspolymer, Dimethylsilanol Hyaluronate, Hydrolyzed Calcium Hyaluronate, Sodium Sulfated Hyaluronate, Madecassoside, Beta-Glucan, Sodium Stearoyl Hyaluronate, Sodium Oleoyl Hyaluronate

FREE FROM: Artificial Fragrance, Essential Oils, Alcohol (Denatured), Parabens, Sulfates, Mineral Oil, Silicones, Colorants, Gluten, Animal-Derived Ingredients
04

Where it fits in your routine

ROUTINE
1
Cleanser
2
Toner
3
This Serum
4
Essence/Ampoule
5
Moisturizer
6
Sunscreen (AM)

Apply to slightly damp skin after toner for maximum absorption. Can be layered 2-3 times for extra hydration. Best used both AM and PM.

05

How to use

HOW TO USE
1

Cleanse & Tone

Start with clean skin. Apply your toner and leave skin slightly damp - this helps hyaluronic acid work more effectively by giving it moisture to bind to.

2

Dispense 2-3 Drops

Using the dropper, place 2-3 drops of serum onto your palm or directly onto different areas of your face. A little goes a long way with this concentrated formula.

3

Gently Pat to Absorb

Press the serum into your skin using gentle patting motions. Avoid rubbing. The lightweight formula absorbs in approximately 3 seconds.

4

Layer if Needed

For extra hydration on dry days, apply 1-2 additional layers after the first has absorbed. Follow with your regular moisturizer to seal in hydration.

06

Who is it for?

WHO

Perfect for you if:

  • You have dehydrated skin that needs a moisture boost
  • You want lightweight hydration without stickiness or greasiness
  • You have oily or combination skin that gets clogged by heavy products
  • You need a fungal acne-safe hydrating serum
  • You're pregnant or breastfeeding and need safe skincare
  • You have sensitive skin that reacts to fragrances
  • You want to layer hydration without pilling
  • You live in a dry climate or air-conditioned environment

Consider alternatives if:

  • You have very dry skin that needs richer, occlusive formulas
  • You prefer thick, creamy serum textures
  • You want anti-aging actives like retinol or vitamin C in one product
  • You live in an extremely humid climate (may feel redundant)
  • You prefer scented skincare products
07

Skin type compatibility

SKIN TYPES
Oily Skin
Excellent

Lightweight, watery texture absorbs instantly without adding shine or greasiness. Perfect for oily skin that still needs hydration.

Dry Skin
Good

Provides excellent hydration but may need a heavier moisturizer or facial oil on top to lock in moisture, especially in dry climates.

Combination Skin
Excellent

Ideal for combo skin - hydrates dry areas without overwhelming oily zones. Layers beautifully across different face regions.

Sensitive Skin
Excellent

Fragrance-free, clinically tested hypoallergenic formula with soothing ingredients. Excellent for reactive, easily irritated skin.

Acne-Prone Skin
Excellent

Non-comedogenic rating of 0/5 and fungal acne-safe formula. Won't clog pores or trigger breakouts. Safe for acne-prone skin.

Mature Skin
Good

Multiple HA weights help plump fine lines and improve skin texture. Pair with anti-aging actives for comprehensive care.

08

Results timeline

MONTH 2+
Immediately

Instant Hydration Boost

Skin feels immediately hydrated, plump, and refreshed. The lightweight texture absorbs in seconds without any sticky residue.

95% noticed instant hydration
Week 1-2

Improved Skin Texture

Skin begins to feel consistently softer and smoother. Dry patches start to diminish. Makeup applies more evenly.

85% reported smoother skin
Week 3-4

Enhanced Plumpness & Glow

Visible improvement in skin plumpness and radiance. Fine dehydration lines appear reduced. Skin barrier feels stronger.

78% noticed visible plumping
Month 2+

Long-Term Hydration Balance

Skin maintains optimal hydration levels throughout the day. Overall complexion appears healthier and more resilient.

82% saw lasting improvements
09

Ratings by platform

5K+ REVIEWS
Amazon
4.5
Rating
2,800+
Reviews
Main complaint: Some users expected thicker texture; bottle size feels small for daily use
iHerb
4.7
Rating
850+
Reviews
Main complaint: Takes 2 minutes of patting to fully absorb for some users
YesStyle
4.6
Rating
1,200+
Reviews
Main complaint: Packaging varies; some received different bottle designs
Ulta Beauty
4.4
Rating
350+
Reviews
Main complaint: May not provide enough moisture for very dry skin types
10

Pros & cons

BALANCED

Praised

  • Exceptional hydration with 14 types of hyaluronic acid
  • Ultra-lightweight, non-sticky texture
  • Absorbs incredibly fast (3 seconds)
  • Fragrance-free and hypoallergenic
  • Fungal acne and pregnancy safe
  • Works well under makeup
  • Great value for the ingredient quality
  • Layers beautifully without pilling
  • Soothing for sensitive and irritated skin
  • Vegan and cruelty-free formula

Criticized

  • May not be hydrating enough for very dry skin alone
  • 50ml bottle runs out quickly with daily use
  • Dropper can dispense more than needed
  • No anti-aging actives (pure hydration focus)
  • Watery texture not preferred by some users
  • Packaging design varies between batches
11

Budget-friendly alternatives (dupes)

DUPES
82% Match
Dive-In Low Molecular Hyaluronic Acid Cleansing Foam
$19.00
Similar Price

Similar K-beauty competitor with 5 types of HA and ceramides. Slightly more watery texture, faster absorption. Better for soothing with panthenol focus, while Isntree excels at barrier repair with glyceryl glucoside.

68% Match
Hyaluronic Acid 2% + B5 Serum
$9.90
Budget Pick

Western drugstore alternative with 5 forms of HA plus Vitamin B5 and ceramides. Thicker, stickier texture. Lower molecular weight variety but excellent value. May pill under makeup.

55% Match
Hyaluronic Acid Serum
$6.00
Budget Pick

Most affordable option with 1% sodium hyaluronate and glycerin. Simpler formula with fewer HA types. Good entry-level option but less sophisticated multi-layer hydration approach.

12

Comparison with competitors

SIDE-BY-SIDE
Serum
HA Types 5 Types
Lowest MW 500 Da
Size 50ml
Fungal Acne Safe Yes
Added Benefits Panthenol, Ceramide NP, Madecassoside
Texture Watery
Pycnogenol 5%
HA Types 5 Types
Lowest MW Not Specified
Size 30ml
Fungal Acne Safe Yes
Added Benefits Panthenol (B5), Ceramides
Texture Thick, May Pill
Niacinamide Serum
HA Types 1 Type
Lowest MW Standard
Size 30ml
Fungal Acne Safe Yes
Added Benefits Glycerin Only
Texture Light Gel
13

Storage & shelf life

12 MONTHS
Period After Opening (PAO)

12 months after opening

Storage

Store in a cool, dry place away from direct sunlight. Refrigeration optional but can enhance the cooling sensation upon application.

Packaging

Glass dropper bottle with eco-friendly paper box packaging. Isntree uses green tea leaf-based packaging materials.

Travel Friendly

Yes, 50ml is under the 100ml TSA limit for carry-on liquids.

13

Frequently asked questions

FAQ

Yes, this serum is considered safe during pregnancy and breastfeeding. It contains no retinoids, salicylic acid, hydroquinone, chemical sunscreens, or other ingredients commonly flagged during pregnancy. The formula focuses on hydrating and soothing ingredients like hyaluronic acid, glycerin, panthenol, and botanical extracts that are all pregnancy-safe. However, always consult with your healthcare provider if you have specific concerns.

Yes, this serum is fungal acne safe. It has been verified by multiple ingredient checkers including SkinSort and is free from ferments, fatty acids (like oleic acid), esters, polysorbates, and other ingredients that feed malassezia yeast. The formula relies on water-based humectants and hyaluronic acid variants that do not contribute to fungal acne flares.

Yes, absolutely! This hyaluronic acid serum pairs well with all active ingredients. Apply the HA serum first on damp skin to maximize hydration, then follow with your actives. When using retinol, the HA serum helps buffer potential irritation. With vitamin C, apply HA after your vitamin C serum. With AHAs/BHAs, use the HA serum to hydrate and calm skin post-exfoliation. The serum's soothing ingredients (madecassoside, panthenol, beta-glucan) also help minimize irritation from actives.

This serum is excellent for all skin types but particularly excels for oily, combination, sensitive, and acne-prone skin due to its lightweight, non-comedogenic formula. Oily skin users love the fast absorption without greasiness. Those with dry skin can use it but may need to layer it or follow with a richer moisturizer. It's also ideal for dehydrated skin (skin lacking water but not necessarily oil) and for anyone seeking a fragrance-free, sensitive-skin-friendly hydrator.

You'll notice immediate hydration and skin plumping right after the first application. Within 1-2 weeks of consistent use, skin texture improves and feels consistently softer. By weeks 3-4, you should see visible improvements in skin plumpness, reduced fine dehydration lines, and enhanced glow. For long-term barrier strengthening and optimal hydration balance, continue use for 2+ months. Results may vary based on your skin condition and climate.

Apply this serum after cleansing and toning, on slightly damp skin. In the Korean skincare routine order: Cleanser → Toner → THIS SERUM → Essence/Ampoule → Moisturizer → Sunscreen (AM). The key is to apply it while skin is still damp from toner, as hyaluronic acid needs moisture to bind to. You can layer it 2-3 times for extra hydration before moving to the next step.

No, this serum has a comedogenic rating of 0/5 and will not clog pores. The water-based formula contains no oils, silicones, or heavy emollients that could block pores. All forms of hyaluronic acid used are non-comedogenic humectants. The serum is specifically designed to be safe for acne-prone skin and has been verified as fungal acne safe as well.

The serum has a PAO (Period After Opening) of 12 months. Once opened, use within one year for best efficacy and safety. Store in a cool, dry place away from direct sunlight. The 50ml bottle typically lasts 2-3 months with twice-daily use (2-3 drops per application). Look for any changes in color, smell, or texture as signs the product may have expired.

— Skincarisma verdict
4.6 / 5 ★★★★★

Verdict: The Isntree Ultra-Low Molecular Hyaluronic Acid Serum stands out in the crowded HA serum market with its impressive 14-type hyaluronic acid complex and thoughtful formulation. The ultra-low 329 Da molecular weight ensures deep penetration, while higher molecular weights provide surface hydration – offering comprehensive moisture at every skin layer. The addition of glyceryl glucoside (for activating water channels), madecassoside (for soothing), and beta-glucan (for barrier repair) elevates this beyond a simple hydrator. Perfect for oily, combination, sensitive, and acne-prone skin types seeking lightweight yet effective hydration. While very dry skin types may need additional products on top, this is an excellent choice for anyone wanting a clean, fragrance-free, fungal acne-safe serum that delivers on its hydration promises.

Browse related

Product Overview

question
lightbulb What are Quick Product Notes?

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.

muscle Pro Tip Alert!

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.

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Quick Product Notes

Click on icons for more information
question
lightbulb What are Notable Effects & Ingredients?

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.

muscle Pro Tip Alert!

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

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Notable Effects & Ingredients

anti-aging Anti-Aging from 4 ingredient(s):
Hydrolyzed Hyaluronic Acid Hyaluronic Acid Madecassoside Beta-Glucan
brightening Brightening from 3 ingredient(s):
Glycerin Hydrolyzed Hyaluronic Acid Hyaluronic Acid
wound Promotes Wound Healing from 8 ingredient(s):
Glycerin Allantoin Panthenol Hydrolyzed Hyaluronic Acid Sodium Hyaluronate Hyaluronic Acid Hydrolyzed Sodium Hyaluronate Madecassoside
question
lightbulb What are Ingredients Related to Skin Type?

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.

muscle Pro Tip Alert!

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!

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Ingredients Related to Skin Types

Click on icons for more information
dry-skin Dry Skin
5
oily-skin Oily/Acne-Prone Skin
1
sensitive-skin Sensitive Skin
1
question
lightbulb What is the Ingredient Safety Breakdown?

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.

muscle Pro Tip Alert!

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.

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Ingredient Safety Breakdown

EWG Health Ratings
Low risk
Medium risk
High risk
Unknown risk
67% 32%

Product ingredient list

Showing first 5 of 34 ingredients
EWG CIR Ingredient Name & Cosmetic Functions Notes
0 Unknown
Sea Water
Humectant, Solvent
1 Unknown
Water
Solvent, Skin Conditioning
1 Unknown
Methylpropanediol
Solvent
2 A
Glycerin
Solvent, Perfuming, Fragrance, Humectant, Viscosity Decreasing Agent, Hair Conditioning, Skin Protecting, Denaturant, Skin Conditioning
brightening Brightening
Promotes Wound Healing
Hydrating
1 A
Butylene Glycol
Solvent, Skin Conditioning, Masking, Fragrance, Humectant, Viscosity Controlling, Viscositydecreasing Agent
Hydrating
VIEW ALL INGREDIENTS