COSRX THE NIACINAMIDE 15 SERUM 20ML

Values You Can Trust: Vegan-Friendly* / Cruelty-Free / 100% Authentic Guarantee

Self-assessed by Adilsons based on available ingredient data (no animal-derived ingredients detected). / Brand-stated; not certified by an independent body.

This serum is a powerful yet gentle solution for common skin concerns like acne, dullness, and enlarged pores. [cite_start]Formulated with a high concentration of Niacinamide (15%), it works to regulate sebum production, reduce inflammation, and fade post-acne marks[cite: 1386, 1392]. [cite_start]It also helps improve skin texture and strengthens the skin barrier[cite: 1392]. With consistent use, you can expect a clearer, smoother, and more radiant complexion.

Best for: Oily, combination, and acne-prone skin types with enlarged pores, uneven tone, and blemishes. It is also suitable for those with skin sensitivity and those wanting to use a mid-level active without strong side effects.

For a beginner-friendly routine, integrate this serum after cleansing and before moisturizing:

[cite_start]
• 1) Cleanser — use a gentle cleanser to prep your skin[cite: 1560, 1569].
• 2) This product — apply a few drops to your face.
[cite_start]
• 3) Moisturiser — follow with a lightweight moisturizer to seal in hydration[cite: 1386, 1560].

Note: Already own a similar step? [cite_start]Finish that first (substitute, don’t stack)[cite: 1560, 1569].

This serum is a versatile active ingredient suitable for both morning and evening use[cite: 1392, 1559]. [cite_start]A morning application can help control oil and protect your skin from environmental stressors[cite: 1392, 1399].

• 1) Cleanser — gently cleanse to prepare your skin.
• 2) This product — apply a few drops and gently pat into skin.
[cite_start]
• 3) Sunscreen SPF 30+ — always the last step to protect against sun damage[cite: 1384, 1563].

Wait times: 30–60s between watery layers; [cite_start]1–2 min before SPF/makeup[cite: 1562, 1569].

This serum is a crucial step in your evening routine for targeting acne and dullness while supporting your skin's overnight repair process[cite: 1392, 1559].

[cite_start]
• 1) Cleanser (double-cleanse if makeup/water-resistant SPF: oil → water) — thoroughly wash away impurities[cite: 1569].
• 2) This product — apply a few drops to your face and neck.
[cite_start]
• 3) Moisturiser/Oil — apply as the final step to lock in hydration and nourishment[cite: 1386, 1560].

Daily Use — AM/PM:

• Amount: 2–3 drops.
• Apply to: Your face and neck. Avoid the immediate eye area unless eye-safe.
[cite_start]
• Method: After cleansing and toning, apply a few drops to your face and gently pat it in for better absorption[cite: 1562, 1569].
• Frequency: Use daily, morning and night, or as needed. If you are new to the ingredient or have sensitive skin, start with a lower frequency (e.g., every other day) and increase as your skin adapts.

Dosage quick-table:

[cite_start]
• Serum/Essence: 2–3 drops (or 1–2 pumps)[cite: 1569].

If-This / Then-That:

• Very oily T-zone? [cite_start]Focus application on the T-zone and chin to help control excess oil and minimize pores[cite: 1386, 1392].
• Very dry/AC? Use a few drops and follow with a rich moisturizer to prevent dryness and support your skin barrier.
• Sensitive/reactive? Start with once a week and ensure you moisturize well afterward. [cite_start]This serum is gentle enough for most skin types, but a patch test is always recommended[cite: 1559, 1560].

Watchouts: Pilling = not an issue with this product's watery texture; sensitivity = can be caused by overuse or using other strong actives[cite: 1528, 1562]. [cite_start]This serum has a high concentration of niacinamide, so it may cause flushing in some individuals[cite: 1392]. Patch test advised for all new products.

Safety: Avoid broken/irritated skin[cite: 1567]. [cite_start]Stop if burning rash[cite: 1528, 1567]. [cite_start]Teens: start with a very low frequency (once a week) and always follow with a hydrating, gentle moisturizer and daily sunscreen[cite: 1569].

This is a gentle daily item[cite: 1569]. [cite_start]It can be used daily, morning and night, as per the routine maps, to keep skin hydrated and calm[cite: 1569].

PM/AM cheat-sheet: Vitamin C AM daily; Niacinamide AM/PM; AHA/BHA/PHA PM 1–3×/week; [cite_start]Retinal/Retinol PM 2–4×/week[cite: 1569].

Mauritius note: In heat/humidity, keep layers thin; hydrating SPF may replace AM moisturiser[cite: 1569].

Safety: If irritation occurs, reduce frequency to 2×/week, switch to soothing nights, and follow patch-test guidance[cite: 1569].

Immediate: Skin will feel instantly hydrated and refreshed[cite: 1569]. The serum absorbs quickly without a heavy feeling.

2–4 weeks: With consistent use, you may notice a reduction in oiliness and redness[cite: 1386, 1392]. [cite_start]Pores may appear smaller and less prominent as sebum production begins to normalize[cite: 1392].

4–8+ weeks: With consistent use, you should see a significant improvement in overall skin tone, with post-acne marks and sun spots appearing faded[cite: 1392]. [cite_start]Your skin barrier will be strengthened, leading to a healthier, more resilient complexion[cite: 1392].

[cite_start]
• DIY acids: This niacinamide serum offers a safe and gentle way to treat acne, dullness, and enlarged pores, unlike DIY solutions like lemon juice or baking soda, which can cause chemical burns and severe irritation[cite: 1474].
[cite_start]
• Harsh treatments: Niacinamide provides a powerful solution for acne and hyperpigmentation without the risk of dryness or irritation that can come with more aggressive treatments[cite: 1533].

Works with:

[cite_start]
• Retinoids: Niacinamide can mitigate retinoid irritation and they can be used together to improve fine lines and texture[cite: 1392]. [cite_start]Many anti-aging products are formulated with both ingredients[cite: 1712].
[cite_start]
• Most other actives: Niacinamide is a "peacekeeper ingredient" that works well with most other actives, such as peptides, hyaluronic acid, and tranexamic acid[cite: 1392]. [cite_start]It is a versatile ingredient that can be included in most routines without much worry[cite: 1392].
[cite_start]
• Sunscreen: Niacinamide can be used in the morning and layered with sunscreen to protect the skin from sun damage[cite: 1559].

Use carefully:

• Vitamin C (L-Ascorbic Acid): While generally fine in modern formulations, for sensitive skin, it is best to separate the two. [cite_start]Use one in the morning and one at night to avoid any potential efficacy issues[cite: 1392, 1569].

This serum is suitable for all skin types, especially oily, combination, and acne-prone skin, as it regulates sebum production and helps reduce breakouts[cite: 1392]. [cite_start]It also works well for dry skin, as niacinamide strengthens the skin barrier by boosting ceramide production[cite: 1392]. [cite_start]It is also safe for those with skin sensitivity as niacinamide can reduce redness and inflammation[cite: 1392, 1399].

This serum is specifically formulated to address a range of concerns, including:

[cite_start]
• Acne and breakouts[cite: 1386, 1392].
[cite_start]
• Enlarged pores and excess sebum[cite: 1392, 1386].
[cite_start]
• Dullness and uneven tone[cite: 1392].
[cite_start]
• Redness and inflammation[cite: 1392, 1399].
[cite_start]
• Post-acne hyperpigmentation[cite: 1392].

• Official Korean Name: 코스알엑스 더 나이아신아마이드 15 세럼
• Shelf Life/PAO: PAO is 12 months.
• Country of Manufacture: Republic of Korea

Halal Status: Halal-Friendly* / Based on our review, this product contains no ethanol or other denatured alcohols and no haram animal-derived ingredients detected.

Vegan Status: Vegan-Friendly* / Based on our review, this product does not contain any animal-derived ingredients detected.

Animal Testing Policy: The brand states that it does not test on animals, a policy that is in line with South Korea's regulations on domestic animal testing for cosmetics.

Self-assessed by Adilsons based on available ingredient data (no ethanol/denat.; no haram animal-derived ingredients detected). / Self-assessed by Adilsons based on available ingredient data (no animal-derived ingredients detected). / Brand-stated; not certified by an independent body.

MFDS Class: Cosmetic. The product is marketed for its anti-acne and skin brightening properties. [cite_start]Niacinamide is a well-known active ingredient that has been shown to reduce sebum and improve skin tone[cite: 1392, 1386].

Clinical Evidence: The key active ingredient, niacinamide, has been shown in studies to reduce sebum production by 2-5% with consistent use[cite: 1392, 1386]. [cite_start]It has also been shown to significantly lighten hyperpigmented spots by inhibiting melanosome transfer[cite: 1392]. The brand claims that its product is suitable for sensitive skin.

Medical disclaimer: This product is a cosmetic, not a medical treatment. [cite_start]Consult a specialist if you have abnormal symptoms or side effects[cite: 1392, 1560].

Key Actives Explained:

[cite_start]
• Niacinamide (15%): A multifunctional vitamin (B3) that regulates sebum production, reduces inflammation, strengthens the skin barrier, and fades hyperpigmentation[cite: 1392, 1386].
[cite_start]
• N-Acetylglucosamine (NAG): An amino sugar that works synergistically with niacinamide to fade hyperpigmentation and improve skin texture[cite: 1392].
[cite_start]
• Zinc PCA: An anti-inflammatory and antibacterial ingredient that helps to control sebum and calm breakouts[cite: 1685].
[cite_start]
• Allantoin: A soothing compound that promotes cell proliferation and aids in wound healing, making it great for irritated or damaged skin[cite: 1399].

Full INCI: Water, Pentylene Glycol, Niacinamide, Dipropylene Glycol, Methylpropanediol, Centella Asiatica Extract, Ficus Carica (Fig) Fruit Extract, Panthenol, Allantoin, N-Acetylglucosamine, Zinc PCA, Sodium Hyaluronate, Hydroxyethylcellulose, Adenosine, Salicylic Acid, Carbomer, Tromethamine, Polysorbate 20, Xanthan Gum, Ethylhexylglycerin.

Fragrance Status: This product is fragrance-free.

EU Allergens: None declared. This formula is designed to be gentle and low-irritant.

Who should use with caution: Individuals with very sensitive skin, as the high concentration of niacinamide (15%) may cause some flushing or irritation. [cite_start]Those with known niacinamide sensitivity should avoid this product[cite: 1392]. [cite_start]As a precaution, it is best to avoid using this product during pregnancy or breastfeeding[cite: 1565].

Patch test protocol: Apply a small, pea-sized amount of the product to a discreet area like your jawline or behind your ear. Assess the area after 24–48 hours for any signs of redness, itching, or irritation. Re-check the area again at 72 hours. [cite_start]If any burning or rash occurs, discontinue use immediately[cite: 1569, 1560].

If irritation occurs: If you feel your skin is getting too dry or irritated, reduce the frequency of use to every other day or just once a day in the evening. [cite_start]Always follow with a good moisturizer[cite: 1562].

Texture: A watery, lightweight, and slightly viscous liquid that absorbs quickly[cite: 1569].

Scent: Unscented.

pH: The formula is at a pH of around 6.5, which is slightly higher than skin’s natural pH, but is still considered gentle and non-irritating[cite: 1392].

This serum is an excellent choice for Mauritius’s humid climate. Its lightweight, watery texture absorbs quickly without feeling heavy or greasy. [cite_start]The high concentration of niacinamide is ideal for controlling the excess sebum that can lead to clogged pores and breakouts in hot, humid weather[cite: 1386, 1392].

We source our products directly from authorized Korean distributors[cite: 1941]. You can verify authenticity by checking for Korean/English labels, a batch/lot number, and official seals. Many K-beauty products come with an authenticity sticker or code. [cite_start]You can also contact us via WhatsApp to verify your product’s details or for any other questions you might have[cite: 1941].

The efficacy of this product is based on the well-documented benefits of niacinamide[cite: 1392]. [cite_start]Studies have shown that a 2-5% concentration of niacinamide can significantly reduce sebum production and that a 4-5% concentration can lighten hyperpigmentation by inhibiting melanosome transfer[cite: 1392]. [cite_start]The brand claims that its product is clinically proven to be safe for sensitive skin[cite: 1392].

Based on a 2-3 drops dosage used once daily, one 20ml bottle should last for approximately 3-4 months. [cite_start]A reorder would likely be needed every quarter to maintain a consistent routine[cite: 1569].

Soothing & Oil-Control Routine (AM/PM)

• COSRX LOW pH GOOD MORNING GEL CLEANSER 150ML — A gentle, low-pH cleanser to prepare your skin without stripping moisture.
• This product — To control oil, minimize pores, and soothe inflammation.
• COSRX OIL-FREE ULTRA MOISTURIZING LOTION — A lightweight, oil-free moisturizer that provides hydration without clogging pores.

Brightening & Fading Routine (AM/PM)

• Anua HEARTLEAF QUERCETINOL PORE DEEP CLEANSING FOAM 150ML — A gentle foam cleanser to remove impurities.
• This product — To target dullness and post-acne marks.
• Anua 70 INTENSE CALMING CREAM 50ML — A calming cream with Centella Asiatica to lock in moisture and reduce irritation.

This niacinamide serum is an excellent choice if your primary concerns are acne and oiliness. But here are a few other options to consider:

• For a budget-friendly alternative: The Ordinary NIACINAMIDE 10% + ZINC 1% 30ML — Choose this if you want a similar formula with a lower niacinamide concentration and a lower price point. Why: It offers a well-known formula that is effective for controlling oil and minimizing pores.
• For a multi-functional brightening serum: TIA'M VITA B3 SOURCE 40ML — Choose this if you want a serum with a similar niacinamide concentration (10%) that also contains arbutin for enhanced brightening benefits. Why: It combines two powerful brightening ingredients to fade dark spots and even out skin tone.

If you already have a comparable product at home, finish it first to avoid waste and get a fair read on results[cite: 1569].

The product comes in a dark, opaque glass bottle with a dropper dispenser. [cite_start]This helps to protect the ingredients from light and air exposure, maintaining their stability and efficacy[cite: 1941]. The dropper allows for hygienic and precise application. The bottle is designed to be sturdy and travel-friendly. The glass is recyclable in Mauritius.

Positive: "This serum has really helped with my oily skin. My face is less shiny by the end of the day." (Reddit, r/SkincareAddiction, 2024). "I love the watery texture of this serum. It absorbs so quickly and doesn't feel heavy at all." (YesStyle review, 2024). "It's my holy grail for fading post-acne marks." (Amazon customer review, 2024).

Negative: Some users found the high concentration of niacinamide (15%) to be too potent for their sensitive skin, causing some flushing and irritation. [cite_start]A few users reported that the serum felt a little sticky when applied.[cite: 1560].

COSRX is a prominent K-beauty brand known for its commitment to creating simple, effective, and science-backed skincare solutions[cite: 1252]. [cite_start]The name "COSRX" is a blend of "cosmetics" and "RX," symbolizing their focus on dermatological science and prescription-grade results[cite: 1252]. [cite_start]The brand rose to international prominence through its digital-first approach and the viral success of hero products like this one, emphasizing high concentrations of actives and minimalist formulations to cater to acne-prone and sensitive skin[cite: 1252].

[cite_start]
• Niacinamide: A multifunctional vitamin (B3) that regulates sebum production, reduces inflammation, strengthens the skin barrier, and fades hyperpigmentation[cite: 1392, 1386].
[cite_start]
• Hyperpigmentation: A common condition where patches of skin become darker in color than the surrounding skin, often due to an overproduction of melanin[cite: 1384, 1559].
[cite_start]
• Post-acne hyperpigmentation (PIH): Dark spots that are left behind after an acne lesion has healed[cite: 1384, 1559].
• MFDS: The Ministry of Food and Drug Safety, the South Korean regulatory body that oversees cosmetic safety and efficacy claims.

Adilsons | [cite_start]+230 5 778 2336 | info@adilsons.mu [cite: 1955]

We are dedicated to providing you with expertly curated, high-quality Korean skincare products that are gentle, effective, and safe for a tropical climate. [cite_start]Our promise is to offer 100% authentic products sourced directly from authorized distributors, with a focus on education and mindful consumption to help you achieve your skincare goals[cite: 1955].

[cite_start]
• Is this serum too strong for my skin? This serum has a high concentration of niacinamide (15%), which may cause flushing or irritation in some individuals with very sensitive skin[cite: 1392]. [cite_start]It is best to start with a lower frequency and perform a patch test before using[cite: 1560].
• Can I use this with other actives? Yes. [cite_start]Niacinamide is a versatile ingredient that works well with most other actives, such as retinoids and peptides[cite: 1392]. [cite_start]However, it is best to separate it from pure L-ascorbic acid to avoid any potential efficacy issues[cite: 1392].
• Does this serum help with acne? Yes. [cite_start]Niacinamide can help with acne by regulating sebum production, reducing inflammation, and fading post-acne marks[cite: 1386, 1392].

Best For: Individuals with oily, combination, or acne-prone skin who are looking for a potent solution to control sebum, minimize pores, and fade post-acne marks[cite: 1392].

Key Benefits:

[cite_start]
• Reduces excess oil and shine[cite: 1386, 1392].
[cite_start]
• Fades post-acne hyperpigmentation and dullness[cite: 1392].
[cite_start]
• Strengthens the skin barrier and improves texture[cite: 1392].

Keep in Mind:

[cite_start]
• High concentration (15%) may be too potent for some sensitive skin types, and may cause flushing[cite: 1392].
[cite_start]
• May not work as a standalone treatment for severe cystic acne[cite: 1533].

[cite_start]
• Coverage: Island-wide delivery (Mauritius)[cite: 1956].
• Processing & Timing: Orders process in 1–2 business days; usually ready by Day 3 for pickup by our delivery partners/regional team. Partner collection can take up to 1 week. [cite_start]After pickup, delivery typically takes 1–5 business days (weekdays only)[cite: 1956].
[cite_start]
• Express: May be available by region; request on WhatsApp: +230 5 778 2336[cite: 1956].
[cite_start]
• Liquids/Sensitive Items: Serums, toners, liquid makeup (and kits containing liquids) are pickup or door-to-door only; checkout enforces this[cite: 1956].
[cite_start]
• Scheduling: Deliveries run by region on set schedules; we’ll contact you the evening before[cite: 1956].
[cite_start]
• Pickup: Citadelle Mall pickup available[cite: 1956].
[cite_start]
• Returns: No change-of-mind exchanges[cite: 1956].
• Refunds (Summary): For defective/damaged on receipt (report within 48h), wrong item, or manufacturing defect within 6 months. Refunds via bank transfer (7–10 business days); card refunds may incur a 5% processor fee (fee not charged for defects/order errors). [cite_start]Opened skincare/personal-care items are non-returnable (except if damaged on delivery)[cite: 1956].
• Source of Truth: This is a quick snapshot. [cite_start]If anything differs, the policy pages are final[cite: 1956].

Policy Links:

• Refunds & [cite_start]Returns: https://adilsons.mu/policies/refund-policy [cite: 1956]
[cite_start]
• Shipping: https://adilsons.mu/policies/shipping-policy [cite: 1956]