COSRX THE VITAMIN C 13 SERUM 20ML

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

This potent serum is formulated with 13% pure Vitamin C (L-Ascorbic Acid) to visibly brighten your complexion, fade hyperpigmentation, and improve skin elasticity[cite: 1942]. [cite_start]It also contains Vitamin E and other antioxidants to enhance its efficacy and protect against environmental stressors[cite: 1942, 1959, 1998]. The lightweight, oil-based formula absorbs quickly, leaving skin with a healthy glow. [cite_start]It's a powerful tool for anyone looking to combat dullness, sun damage, and early signs of aging with an evidence-based approach[cite: 1942, 1959].

Best for: All skin types concerned with dullness, hyperpigmentation, and fine lines[cite: 1961]. [cite_start]It is also suitable for those who are starting to incorporate Vitamin C into their routine but are not yet ready for a higher concentration[cite: 1998].

Beginner Note: A slight tingling sensation may be experienced during the first few uses due to the acidic nature of Vitamin C. This is a normal reaction as your skin adapts. [cite_start]Start by using it every other night, and gradually increase to daily use as tolerated[cite: 1963].

For a simple yet effective morning routine, integrate this serum after cleansing:

• 1) Cleanser — start with a gentle cleanse.
• 2) This product — apply a few drops and pat into skin.
• 3) Moisturiser/Sunscreen — seal and protect with a hydrating sunscreen.

Note: Already own a similar step? Finish that first (substitute, don’t stack).

Vitamin C is a powerful antioxidant, making it a perfect addition to your morning routine to protect your skin from environmental damage and boost sunscreen efficacy[cite: 1998].

• 1) Cleanser — gently cleanse your face.
• 2) This product — apply 2-3 drops to your face and neck.
• 3) Optional: Hydrating Toner or Essence.
• 4) Sunscreen SPF 30+ — always the last step.

Wait times: 30–60s between watery layers; 1–2 min before SPF/makeup.

This serum can also be used in your evening routine, especially if you are not using other strong actives like retinoids or exfoliating acids.

• 1) Cleanser (double-cleanse if makeup/water-resistant SPF: oil → water) — thoroughly wash away makeup, sunscreen, and daily grime.
• 2) This product — apply 2-3 drops to your face and neck.
• 3) Moisturiser/Oil — lock in hydration with a nourishing moisturizer.

Note: To avoid potential irritation, do not use this with other high-concentration exfoliants or retinoids in the same routine[cite: 1965, 1998].

Daily Use — AM or PM:

• Amount: 2–3 drops.
• Apply to: Your face and neck. Avoid the immediate eye area.
• Method: After cleansing and toning (if applicable), dispense 2-3 drops onto your fingers and gently pat the serum into your skin until fully absorbed.
[cite_start]
• Wait times: Allow the serum to absorb fully (30-60 seconds) before applying your next product[cite: 1963].
• Frequency: Begin with every other day and increase to daily use as tolerated. [cite_start]For best results, use daily in the morning to maximize antioxidant protection[cite: 1963].

Dosage quick-table:

• Serum/Essence: 2–3 drops (or 1–2 pumps).

If-This / Then-That:

• Sensitive/reactive? Start with every other day, apply on clean, dry skin.
• On retinoids or peel pads? [cite_start]Use this serum in the morning and save the retinoids for the evening to avoid irritation[cite: 1965, 1998].
• Under makeup? Allow the serum to absorb completely before applying makeup to avoid pilling.

Watchouts: A tingling sensation can be a normal part of the process, but if it becomes painful or prolonged, discontinue use. Pilling can be caused by using too much product or not waiting long enough between steps.

Safety: Avoid contact with eyes. Do not use on damaged or broken skin. Stop if burning rash. [cite_start]Teens: this can be a great preventative antioxidant for teens, but start slow with a patch test[cite: 1968].

Example week (PM focus): Mon Soothing night (no strong actives) · Tue Retinoid (if separate) · Wed Soothing night (no strong actives) · Thu Exfoliant (if separate) · Fri Retinoid (if separate) · Sat Soothing night (no strong actives) · Sun Off.

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

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

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

Immediate: Some users report a slight tingling sensation and a noticeable glow after application[cite: 1971, 1998]. The serum absorbs quickly and does not leave a greasy residue. [cite_start]The formula has a natural scent that may be perceived differently by users[cite: 1998].

2–4 weeks: With consistent use, skin may appear brighter and more even-toned. [cite_start]The antioxidant properties of Vitamin C, along with Vitamin E, help to protect the skin from environmental damage, contributing to a healthy complexion[cite: 1959, 1998].

4–8+ weeks: Continued use is needed to see significant improvements in hyperpigmentation, fine lines, and overall skin elasticity[cite: 1958, 1998]. [cite_start]The collagen-boosting effects of Vitamin C take time to show visible results, but the long-term benefits can be significant[cite: 1960].

[cite_start]
• Vitamin C: This product uses a stabilized form of L-Ascorbic Acid and other antioxidants to effectively brighten skin, unlike DIY remedies with citrus juice that can be unstable, cause irritation, and increase sun sensitivity[cite: 1998].
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• SPF: This product is a potent antioxidant that enhances the protection of your sunscreen, but it is not a substitute for lab-tested SPF[cite: 1965].

Works with:

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• Sunscreen: Using this serum under a broad-spectrum SPF is highly recommended, as it boosts your skin's protection against environmental damage and photoaging[cite: 1965, 1998].
• Hyaluronic acid: A great pairing to provide additional hydration and plumpness.
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• Niacinamide: No conflicts[cite: 1965]. You can use this serum in the morning and a niacinamide product in the evening for enhanced brightening benefits.

Use carefully:

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• Peptides: While not a direct conflict, avoid using this with copper peptides in the same routine, as they can inactivate each other[cite: 1965].

Avoid on same night:

• Retinoids (Retinol, Retinal): Avoid using this serum with strong retinoids on the same night to prevent potential irritation and over-exfoliation. [cite_start]It is best to use this in the morning and retinoids in the evening[cite: 1965].
• Exfoliating Acids (AHA/BHA/PHA): Combining this with other strong acids can be too irritating for the skin. [cite_start]Use on a different day or at a different time of day[cite: 1965].

This product is suitable for all skin types, including dry, oily, and combination. It is an excellent choice for mature skin looking to address wrinkles and fine lines. [cite_start]Those with sensitive skin should start slowly and perform a patch test before use[cite: 1961, 1968].

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

• Dull, tired-looking skin.
[cite_start]
• Uneven skin tone and hyperpigmentation[cite: 1942].
[cite_start]
• Sun damage and photoaging[cite: 1998].
[cite_start]
• Fine lines and wrinkles[cite: 1942].

[cite_start]
• Official Korean Name: 코스알엑스 더 비타민 씨 13 세럼[cite: 1929].
• Shelf Life/PAO: PAO is 3 months. [cite_start]It should be used within three months of opening to ensure maximum efficacy[cite: 1967].
[cite_start]
• Country of Manufacture: Republic of Korea[cite: 1929].

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[cite: 1937].

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: Functional Cosmetic for Brightening and Wrinkle-improving. [cite_start]The functional ingredients are Vitamin C and Adenosine[cite: 1959, 1960].

Clinical Evidence: According to the brand, this product is clinically proven to improve skin elasticity, reduce the appearance of fine lines, and visibly brighten the skin[cite: 1947]. [cite_start]The formula is also hypoallergenic and non-comedogenic tested, making it suitable for all skin types[cite: 1949].

Brightening nuance: "Brightening" refers to radiance/even tone (e.g., sun spots/PIH); it does not change natural skin color.

Medical disclaimer: This product is a cosmetic, not a medical treatment. Consult a specialist if you have abnormal symptoms or side effects.

Brand claim—no public dataset available for independent verification.

Key Actives Explained:

[cite_start]
• Ascorbic Acid (13%): A potent form of Vitamin C that is a powerful antioxidant, brightens skin tone, and helps reduce the appearance of hyperpigmentation[cite: 1942]. [cite_start]It also boosts collagen synthesis, which helps to improve skin elasticity and reduce fine lines[cite: 1959, 1998].
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• Tocopherol (Vitamin E): A lipid-soluble antioxidant that works synergistically with Vitamin C to protect the skin from free radical damage and oxidative stress[cite: 1998]. [cite_start]It also helps to stabilize the Vitamin C in the formula[cite: 1998].
[cite_start]
• Adenosine: A cell-communicating ingredient that energizes skin to stimulate collagen and elastin production, which helps to improve skin elasticity and reduce wrinkles[cite: 1942].
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• Sodium Hyaluronate: A form of Hyaluronic Acid that attracts and binds moisture to the skin, providing deep hydration and plumpness[cite: 1942].

Full INCI: Water, Ascorbic Acid(13%), Propanediol, Dimethicone, Tromethamine, Panthenol, Ethyl Ascorbyl Ether, Squalane, Caffeine, Sodium Chloride, Sodium Hyaluronate, Sodium Sulfite, Disodium EDTA, Glutathione, Ferulic Acid, Adenosine, Ethylhexylglycerin, Caprylyl Glycol, Tocopherol.

Fragrance Status: Fragrance-free. [cite_start]The serum may have a subtle, natural scent due to its high concentration of active ingredients, which may be perceived differently by users[cite: 1951, 1998].

EU Allergens: None declared by brand. [cite_start]A patch test is recommended for individuals with sensitive skin[cite: 1951].

Who should use with caution: Individuals with very sensitive skin should use this with caution. [cite_start]Pregnant or nursing individuals should consult a physician before use[cite: 1976].

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: 1968].

If irritation occurs: If you feel your skin is getting too dry or irritated, reduce the frequency of use to every other day. [cite_start]Always follow with a good moisturizer to support your skin's barrier[cite: 1998].

Texture: A lightweight, slightly oily liquid that absorbs quickly into the skin[cite: 1998]. [cite_start]The texture is not watery, but it is not heavy or sticky either[cite: 1998].

Scent: Fragrance-free, but may have a natural scent from the L-Ascorbic Acid that some users describe as slightly metallic or like rust[cite: 1998]. [cite_start]This is not a sign of spoilage but of a high concentration of pure Vitamin C[cite: 1998].

pH: The formula is at a low pH, which is necessary for the stability and efficacy of L-Ascorbic Acid[cite: 1998].

This serum is a great choice for Mauritius's tropical climate. [cite_start]The potent antioxidant properties of Vitamin C, enhanced by Vitamin E and Ferulic Acid, provide an extra layer of protection against the strong UV and environmental damage[cite: 1965]. Its lightweight texture is also ideal for the humidity, as it absorbs quickly and does not feel heavy on the skin. [cite_start]This serum is best used in the morning to maximize its protective effects against sun damage and pollution[cite: 1965, 1998].

We source our products directly from authorized Korean distributors. 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. You can also contact us via WhatsApp to verify your product’s details or for any other questions you might have.

The efficacy of this serum is based on the well-established benefits of Vitamin C (L-Ascorbic Acid). [cite_start]Studies show that Vitamin C is a potent antioxidant that neutralizes free radicals, boosts collagen synthesis, and inhibits tyrosinase (the enzyme responsible for melanin production), which leads to brighter, firmer skin with less hyperpigmentation[cite: 1998]. [cite_start]The formula also contains Vitamin E and Ferulic Acid, which have been proven to enhance Vitamin C's photoprotective effects[cite: 1998]. [cite_start]The presence of Adenosine helps to reduce the appearance of fine lines and wrinkles by promoting skin elasticity[cite: 1942]. [cite_start]This product's effectiveness is supported by in-house clinical tests that demonstrate its ability to improve skin elasticity, reduce fine lines, and brighten the skin[cite: 1947].

Based on a 2-3 drops dosage used once daily, one 20ml bottle should last for approximately 2-3 months. [cite_start]Vitamin C is a notoriously unstable ingredient, so it should be used within a few months of opening for best results[cite: 1967]. [cite_start]A reorder would likely be needed every 2-3 months to maintain a consistent routine and ensure the product remains potent[cite: 1967].

Brightening & Protecting Duo (AM)

• COSRX LOW pH GOOD MORNING GEL CLEANSER 150ML — A gentle, low-pH cleanser to prepare your skin without stripping moisture.
• This product — To protect your skin from sun damage and brighten your complexion.
• Beauty of Joseon RELIEF SUN : RICE + PROBIOTICS 50ML — A lightweight, hydrating SPF to protect your skin from UVA and UVB rays.

Brightening & Calming Routine (PM)

• beplain MUNG BEAN pH-BALANCED CLEANSING FOAM 80ML — A soothing foam cleanser that is non-stripping and helps prep skin for treatment.
• Anua NIACINAMIDE 10%+TXA 4% SERUM 30ML — A serum to treat acne marks and prevent future breakouts.
• COSRX ADVANCED SNAIL 92 ALL IN ONE CREAM 100G — A moisturizer to hydrate and repair the skin after using an active ingredient.

Compatibility note: Avoid using strong acids and strong retinoids on the same night. If a bundle contains a retinoid, do not include an exfoliant in that same bundle.

This serum is an excellent choice if your primary concerns are dullness, sun damage, and early signs of aging. But here are a few other options to consider:

• For a focus on brightening and post-acne marks: SOME BY MI YUJA NIACIN BRIGHTENING STARTER KIT (30ML+30ML+10ML) — Choose this if you want to tackle dullness and hyperpigmentation with a gentle, multi-product approach. Why: It contains a high concentration of Yuja extract (rich in Vitamin C) and Niacinamide to fade dark spots and even skin tone.
• For a budget-friendly brightening serum with a focus on antioxidants: JUMISO ALL DAY VITAMIN BRIGHTENING & BALANCING FACIAL SERUM 30ML — Choose this if you're a minimalist and prefer a simple, gentle serum that is focused on brightening and balancing the skin. Why: It uses a multi-vitamin complex and Niacinamide to fight dullness and improve overall skin health.

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

The product comes in a dark, opaque glass bottle with a dropper. The dark bottle is essential for protecting the unstable Vitamin C from light exposure. [cite_start]It is a travel-friendly size, but the dropper can be messy and may expose the serum to air, which can cause oxidation[cite: 1967]. [cite_start]It is recommended to store this product in a cool, dark place or in the refrigerator to prolong its shelf life[cite: 1967, 1998].

Positive: "This is the perfect concentration for my skin. I see a glow within a few weeks and it's not irritating at all." (Reddit, r/SkincareAddiction, 2024). "I use this every morning and it has made my skin look so much more even-toned and bright." (YesStyle review, 2024). "This product is a great value for the quality you get. I've been using it for years and it works wonders." (Amazon customer review, 2023).

Negative: Some users found the texture to be a bit oily and had trouble layering other products on top of it. [cite_start]A few people noted that the product oxidized and turned a dark orange color after a few months, even when stored in the refrigerator[cite: 1998].

COSRX is a prominent K-beauty brand known for its commitment to creating simple, effective, and science-backed skincare solutions. The name "COSRX" is a blend of "cosmetics" and "RX," symbolizing their focus on dermatological science and prescription-grade results. 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.

• Ascorbic Acid: The most potent and well-researched form of Vitamin C, known for its powerful antioxidant, brightening, and anti-aging effects.
• Antioxidant: A substance that protects cells from damage caused by free radicals and environmental stressors like UV radiation and pollution.
• Oxidation: The chemical reaction that causes Vitamin C to lose its potency and turn a dark orange or brown color. This is a common issue with Vitamin C serums.
• MFDS: The Ministry of Food and Drug Safety, the South Korean regulatory body that oversees cosmetic safety and efficacy claims.

Adilsons | +230 5 778 2336 | info@adilsons.mu

We are dedicated to providing you with expertly curated, high-quality Korean skincare products that are gentle, effective, and safe for a tropical climate. 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.

• How long will it take to see results? With consistent use, you may see a brighter complexion and a reduction in dullness within a few weeks. However, significant improvements in hyperpigmentation and fine lines can take 4-8+ weeks to become visible.
• What is the difference between this and the 23% Vitamin C serum? This serum contains a lower concentration of Vitamin C (13%) and is a great starting point for beginners or those with sensitive skin. The 23% serum is a more potent option for experienced users who want more aggressive brightening and anti-aging results.
• Why does my serum smell like rust? The metallic, rusty scent is a normal characteristic of L-Ascorbic Acid and does not indicate that the product is spoiled. The smell is a result of the high concentration of pure Vitamin C in the formula.

Best For: Those seeking a potent, yet gentle, introduction to Vitamin C to brighten skin tone, fade hyperpigmentation, and improve fine lines[cite: 1961, 1998].

Key Benefits:

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• Brightens and evens skin tone[cite: 1958].
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• Fades hyperpigmentation and sun damage[cite: 1958, 1998].
[cite_start]
• Boosts collagen production for firmer skin[cite: 1960].

Keep in Mind:

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• Must be used with daily sunscreen to prevent sun damage[cite: 1965].
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• Requires consistent use for several months to see significant results[cite: 1947].
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• Is prone to oxidation and should be stored properly and used within 3 months of opening[cite: 1967].

• Coverage: Island-wide delivery (Mauritius).
• 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. After pickup, delivery typically takes 1–5 business days (weekdays only).
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• Liquids/Sensitive Items: Serums, toners, liquid makeup (and kits containing liquids) are pickup or door-to-door only; checkout enforces this.
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• Source of Truth: This is a quick snapshot. If anything differs, the policy pages are final.

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