No.4 Hydrating Glow Mineral Toner
No.4 Hydrating Glow Mineral Toner
Product Description
Product overview
A glow-boosting hydrating toner infused with 89% mineral-rich thermal water and 5 types of hyaluronic acid. Features PHA for gentle exfoliation and niacinamide for brightening, leaving skin plump, smooth, and perfectly prepped for your skincare routine or makeup.
Deep 7-Layer Hydration
Thermal water penetrates 7 layers of skin, clinically shown to improve makeup base by 99.74% after a single use.
Texture & feel
SENSORYDeep 7-Layer Hydration
Thermal water penetrates 7 layers of skin, clinically shown to improve makeup base by 99.74% after a single use.
Gentle Exfoliation
PHA (Gluconolactone) gently removes dead skin cells without irritation, suitable for sensitive skin types.
Brightening Effect
Niacinamide and Licorice Root Extract work together to even skin tone and enhance natural radiance.
Soothing Botanicals
Centella Asiatica, Madecassoside, and Chamomile calm irritation and support skin barrier repair.
Safety & compatibility
SAFEFree from retinoids, high-strength salicylic acid, and hydroquinone. Contains only mild Betaine Salicylate which is gentle and pregnancy-compatible.
Contains botanical extracts that may be problematic for some FA-prone skin. Patch test recommended. No fermented ingredients or polysorbates.
Rating 1/5. Lightweight, non-greasy formula with no pore-clogging oils or heavy emollients. Safe for acne-prone skin.
Clinically tested for skin irritation. Low acidic pH formula (5.0-6.0) respects skin's natural barrier. Free from alcohol, fragrance, and essential oils.
Ingredient breakdown
INGREDIENTSThermal Hot Spring Water (Onsen-Sui) 89%Star Ingredient
Mineral-rich hot spring water that provides deep hydration and delivers essential minerals to nourish the skin. Creates a spa-like treatment experience.
- Function: Deep hydration across 7 skin layers
- Benefit: Improves skin texture and makeup adhesion
- Clinical: 99.74% improvement in makeup base after single use
5 Types of Hyaluronic Acid Multi-WeightProven
A complex of five different molecular weights of hyaluronic acid that hydrate at multiple skin depths for comprehensive moisture retention.
- Sodium Hyaluronate: Standard HA for surface hydration
- Sodium Hyaluronate Crosspolymer: 5x water-binding capacity
- Hydrolyzed Hyaluronic Acid: Penetrates deeper layers
- Hyaluronic Acid: Natural moisturizing factor
- Hydrolyzed Sodium Hyaluronate: Ultra-low MW for deep delivery
Gluconolactone (PHA)Proven
A next-generation polyhydroxy acid that provides gentle exfoliation without the irritation of traditional AHAs. Also acts as a humectant and antioxidant.
- Function: Gentle chemical exfoliation
- Benefit: Smooths texture without sun sensitivity
- Suitable for: Sensitive, rosacea-prone, and post-procedure skin
Niacinamide (Vitamin B3)Proven
A multi-functional superstar ingredient that brightens, strengthens the skin barrier, and helps control sebum production.
- Anti-aging: Reduces fine lines at 4-5% concentration
- Brightening: Fades dark spots and evens skin tone
- Barrier: Increases ceramide synthesis for healthier skin
Centella Asiatica & MadecassosideProven
The famous "Cica" ingredient known for its wound healing, anti-inflammatory, and skin-soothing properties. Madecassoside is one of its most active compounds.
- Wound healing: Stimulates collagen synthesis
- Soothing: Reduces redness and irritation
- Anti-aging: Antioxidant and UV protection support
34 ingredients
Onsen-Sui (Hot Spring Water), 1,2-Hexanediol, Methylpropanediol, Glycerin, Niacinamide, Sorbitol, Water, Xylitol, Hydroxyethyl Urea, Gluconolactone, Sodium Polystyrene Sulfonate, Hydroxyethyl Cellulose, Polyglyceryl-10 Laurate, Betaine Salicylate, Polyquaternium-51, Disodium EDTA, Morinda Citrifolia Extract, Carica Papaya Fruit Extract, Butylene Glycol, Madecassoside, Centella Asiatica Extract, Pentylene Glycol, Polygonum Cuspidatum Root Extract, Gold Extract, Camellia Sinensis Leaf Extract, Glycyrrhiza Glabra Root Extract, Sodium Hyaluronate, Chamomilla Recutita Flower Extract, Rosmarinus Officinalis Leaf Extract, Sodium Hyaluronate Crosspolymer, Hydrolyzed Hyaluronic Acid, Hyaluronic Acid, Hydrolyzed Sodium Hyaluronate
Where it fits in your routine
ROUTINEUse immediately after cleansing when skin is still slightly damp for best absorption. Can layer 2-3 times for extra hydration (7-skin method friendly).
How to use
HOW TO USECleanse Your Face
Start with a clean face. Use your regular cleanser and pat skin until almost dry (slightly damp is ideal).
Dispense Toner
Pour an appropriate amount onto a cotton pad or directly into your palms. About 2-3 pumps or a coin-sized amount.
Apply to Face
Gently wipe outward with cotton pad to exfoliate, OR pat into skin with hands for deeper hydration. Both methods work well.
Layer if Desired
For extra hydration or the 7-skin method, repeat application 2-3 times before moving to the next step. Perfect as a cotton pad mask for 1 minute.
Who is it for?
WHOPerfect for you if:
- You have dehydrated or dull skin needing a glow boost
- You want to improve makeup adhesion and longevity
- You prefer lightweight, non-sticky hydration
- You need gentle exfoliation without irritation
- You're building a Korean skincare routine
- You have combination or oily-dehydrated skin
- You're pregnant or breastfeeding and need safe options
Consider alternatives if:
- You have severe fungal acne (patch test first)
- You need heavy-duty anti-aging actives like retinol
- You prefer cream-based, rich toners for very dry skin
- You're looking for strong BHA/AHA exfoliation
- You're allergic to any botanical extracts
Skin type compatibility
SKIN TYPESLightweight, watery texture absorbs instantly without adding shine. Controls oil while providing necessary hydration.
Provides excellent hydration base but may need heavier moisturizer on top. Great for layering multiple times.
Balances hydration across different face zones without causing T-zone oiliness or cheek dryness.
Fragrance-free, low pH formula clinically tested for irritation. Centella and Chamomile provide soothing benefits.
Non-comedogenic formula with gentle BHA (Betaine Salicylate). Won't clog pores. Patch test if FA-prone.
Results timeline
WEEK 6-8Instant Hydration & Glow
Skin feels immediately hydrated and refreshed. Visible dewy glow appears right after application. Makeup applies more smoothly.
95% noticed immediate hydration boostImproved Texture & Smoothness
PHA begins gentle exfoliation. Skin texture becomes noticeably smoother. Absorption of following skincare products improves.
80% reported smoother skinBrighter, More Even Tone
Niacinamide and botanical extracts show visible brightening effects. Dark spots begin to fade. Overall complexion looks more radiant.
75% noticed brighter complexionLong-Term Skin Health
Skin barrier is strengthened. Consistent glow becomes the new normal. Skin appears healthier, plumper, and more resilient.
85% would repurchaseRatings by platform
897+ REVIEWSPros & cons
BALANCEDPraised
- Instant hydration and visible glow
- Lightweight, non-sticky formula
- Excellent makeup primer effect
- Gentle enough for sensitive skin
- Fragrance-free and alcohol-free
- Good value for 200ml size
- Works well with layering/7-skin method
- Pregnancy and breastfeeding safe
Criticized
- May be too lightweight for very dry skin
- Botanical extracts may not suit FA-prone skin
- Brightening takes several weeks to show
- Bottle dispensing could be improved
- Not as hydrating as cream-type toners
- PHA may cause purging initially for some
Budget-friendly alternatives (dupes)
DUPESUses deep sea water instead of thermal water. Similar lightweight texture and hydration. Fungal acne safe. Lacks PHA exfoliation but equally gentle.
50% hyaluronic acid focused formula. More viscous texture but similar hydration. No exfoliating acids. Better for HA purists seeking maximum moisture.
Classic hydrating toner with HA and plant extracts. Slightly thicker consistency. No thermal water or PHA. Great for sensitive skin seeking simplicity.
Uses propolis instead of thermal water for nourishment. Better for acne-prone skin. Slightly different glow effect. No exfoliating ingredients.
Comparison with competitors
SIDE-BY-SIDEKlairs Supple Prep Toner
Storage & shelf life
12 MONTHS12 months after opening. Check the PAO symbol on packaging.
Store in a cool, dry place away from direct sunlight. No refrigeration required but can be stored cool for a refreshing application.
Plastic bottle with flip-top cap. Allows for easy dispensing onto cotton pads or hands.
Yes, but exceeds 100ml carry-on limit. Decant into smaller container for travel or pack in checked luggage.
Frequently asked questions
FAQYes, this toner is considered safe for pregnancy and breastfeeding. It does not contain retinoids, high-concentration salicylic acid, hydroquinone, or chemical sunscreen filters. The only exfoliating acid present is Betaine Salicylate, which is a mild, gentler form of BHA that is generally considered safe during pregnancy. However, always consult with your healthcare provider if you have specific concerns.
Use with caution if you're prone to fungal acne. While the formula doesn't contain common FA triggers like polysorbates, fermented ingredients, or high-comedogenic oils, it does contain botanical extracts (Centella, Green Tea, Papaya) that some FA-prone individuals may react to. Unlike Numbuzin No.1 which is explicitly FA-safe, the No.4 hasn't been specifically tested for malassezia compatibility. We recommend patch testing before full-face use.
Yes, but with considerations. This toner contains gentle PHA (Gluconolactone) and mild BHA (Betaine Salicylate), so when combining with other exfoliating acids, monitor your skin for over-exfoliation. For retinol: safe to use together, apply toner first. For Vitamin C: compatible, you can layer either order. For strong AHA/BHA: consider alternating days to avoid irritation. If new to actives, introduce one product at a time.
This toner excels for combination, oily, and normal skin types seeking lightweight hydration with a glow effect. It's also excellent for sensitive skin due to its fragrance-free, low pH formula. Dry skin types can use it but may need additional hydrating layers or a richer moisturizer on top. It's particularly loved by those who want their skincare to double as makeup prep.
Results vary by benefit: Immediate hydration and glow are visible right away. Smoother texture typically appears within 1-2 weeks as PHA gently exfoliates. Brightening and evening of skin tone from niacinamide usually becomes noticeable around weeks 3-4. Long-term skin health improvements (stronger barrier, consistent radiance) develop over 6-8 weeks of consistent use.
Apply immediately after cleansing as step 2 in your routine. The order is: Cleanser → This Toner → Essence (optional) → Serum → Moisturizer → Sunscreen (AM). Apply to slightly damp skin for best absorption. You can apply 2-3 layers using the 7-skin method for extra hydration, or soak cotton pads and use as a quick sheet mask for 1 minute.
No, this toner has a very low comedogenic rating of 1/5. The formula is lightweight, water-based, and doesn't contain heavy oils or pore-clogging ingredients. The PHA and Betaine Salicylate actually help keep pores clear by gently exfoliating. It's suitable for acne-prone skin, though as with any product, individual reactions can vary.
The toner has a PAO (Period After Opening) of 12 months. Once opened, use within one year for optimal efficacy and safety. Store in a cool, dry place away from direct sunlight to maintain product integrity. The 200ml bottle typically lasts 2-3 months with twice-daily use, well within the PAO period.
Verdict: Numbuzin No.4 Hydrating Glow Mineral Toner delivers on its promises of instant hydration and visible glow. The 89% thermal water base combined with 5 types of hyaluronic acid creates a uniquely refreshing experience that genuinely improves makeup application. The addition of gentle PHA and niacinamide provides long-term skin benefits without irritation. While it may be too lightweight for very dry skin and requires caution for fungal acne sufferers, it's an excellent choice for most skin types seeking a hydrating, brightening toner at a reasonable price point. A solid K-beauty essential that lives up to the hype.
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 |
|---|---|---|---|
| 1 |
Water
Solvent, Skin Conditioning
|
|
|
| 1 |
1,2-Hexanediol
Solvent, Skin Conditioning
|
Hydrating
|
|
| 1 |
Methylpropanediol
Solvent
|
|
|
| 2 |
Glycerin
Solvent, Perfuming, Fragrance, Humectant, Viscosity Decreasing Agent, Hair Conditioning, Skin Protecting, Denaturant, Skin Conditioning
|
Promotes Wound Healing
Hydrating
|
|
| 1 |
Sorbitol
Skin Conditioning, Fragrance, Humectant, Flavoring Agent, Plasticizer, Masking
|
Hydrating
|







