Cos De Baha Azelaic Acid 10% Serum 30ml

Values: 100% Genuine (Adilsons policy) · FA-Conditional (see Sensory section) · Fragrance-Free (confirmed via INCI) · Vegan-Friendly* / Cruelty-Free* (brand-stated).

Pros: multi-mechanism (acne, redness, and pigment) in one product, real 10% brand-stated concentration, reformulated to remove witch hazel/eucalyptus at customer request per the brand's own blog. Caveats: independent reviews are genuinely mixed — some report clear improvement, others report minimal rosacea change or unexpected breakouts; contains Polysorbate 20, a mild emulsifier some fungal-acne-prone users react to.

Classification: YELLOW — 14+ with guidance. A 10% acid-strength active is not appropriate for pre-teen skin, which does not yet need acne-scar or rosacea-targeted correction and has a less developed barrier. A teen with genuine, persistent acne can use this under adult/dermatologist guidance starting at low frequency; it is not a first skincare product for a beginner of any age.

Step 1 (When): start PM, 3x/week. Step 2 (How much): pea-size for the whole face. Step 3 (How): apply to clean, dry or slightly damp skin, wait 1-3 minutes before moisturizer.

Introduce this as the ONLY new product in your routine. Wait a full 14 days before adding anything else. This isolation window ensures you can identify whether any reaction is caused by this specific product.

1. Double cleanse if wearing SPF/makeup. 2. Toner (optional). 3. Azelaic Acid 10% Serum — pea-size, wait 1-3 minutes. 4. Moisturizer. In a 4-night skin-cycling protocol, this can occupy the Exfoliation/acne-control night, kept separate from retinol nights.

1. Cleanse. 2. Toner (optional). 3. Azelaic Acid 10% Serum (if tolerated AM). 4. Moisturizer. 5. Sunscreen SPF50+ PA++++ (mandatory — protects the PIH-fading progress and general skin health, even though azelaic acid itself is not strongly photosensitizing).

Technique: pat/press, do not rub — friction increases irritation on already-inflamed acne/rosacea skin. Skin state: dry or lightly damp. Wait time: 1-3 minutes before moisturizer. Hands deliver 100% of product; cotton pads absorb approximately 30-40% — use hands.

This is an encyclopedia map of all product types. You do not use all of these daily. You select modules based on your skin state.

Global rules: viscosity ladder thinnest to thickest, water-phase before oil-phase, exfoliating acids apply on dry or lightly damp skin, one active lane only per routine. If the routine pills, stings, or feels heavy, reduce layers, not increase.

AM Maximum Stack: 1. Rinse/gentle cleanse (optional). 2. pH-prep toner (optional). 3. Hydrating toner layers (optional). 4. Essence (optional). 5. Booster/soothing serum (optional). 6. Antioxidant lane (choose one, different from this product). 7. Pigment/acne-control lane — this product's role. 8. Hydration serum lane (optional). 9. Moisturizer. 10. Sunscreen SPF50+ PA++++ (non-negotiable).

PM Maximum Stack: 1. Micellar pre-cleanse (optional). 2. Oil cleanser if wearing SPF/makeup. 3. Water cleanser. 4. pH-prep toner (optional). 5. Soothing serum (optional). 6. Anchor product — this Azelaic Acid Serum, on its own night, not combined with a separate retinol or strong AHA/BHA. 7. Moisturizer. 8. Occlusive seal (optional). Do not layer retinoids with AHA/BHA/strong acids in the same night; keep one lane per night.

Lane strictness: Retinoid OR Exfoliation/Azelaic-acne lane OR Strong Vitamin C (LAA) per routine; barrier/hydration can always accompany.

Tier: light fluid, solubilized by Polysorbate 20. Layering rule: apply after cleansing/toner, before moisturizer, as the active step. Phase: water-phase with an emulsified acid fraction.

Rest days: at least 2-4 nights per week while building tolerance, more if any stinging persists. Overuse warning: exceeding your tolerance frequency does NOT speed results — it produces barrier damage and can worsen rosacea redness rather than calm it.

Purging vs. Reaction: real-world reviews for this exact product include a report of "unexpected breakouts after a few uses" that could reflect either purging or a true reaction. PURGING occurs in your usual breakout areas and resolves in 4-6 weeks. A REACTION — new-area breakouts, burning, swelling, or worsening rather than improving — means stop and follow the 72-Hour Barrier Reset below.

Prerequisites: your routine MUST already include a gentle cleanser and daily SPF before starting this. Without these, this product causes more harm than benefit.

Graduation ladder: if you are new to azelaic acid, COS DE BAHA Azelaic Acid 5% Serum is a real, in-stock, lower-strength starting point from the same brand before stepping up to this 10% version.

Barrier index gate: if your skin stings on moisturizer or shows visible flaking, repair first with SKIN1004 Centella Probio-Cica Enrich Cream before starting this.

Acne: mild antibacterial action plus normalized keratinization reduces clogged pores. Rosacea-related redness: anti-inflammatory action, though individual response varies per available reviews. PIH (dark marks): tyrosinase inhibition fades brown/tan post-acne marks. What it cannot do: it cannot fade red/pink PIE marks the same way it fades brown PIH, it cannot replace prescription treatment for moderate-severe rosacea, and it cannot physically shrink pores.

Sunscreen (mandatory AM): primary — Beauty of Joseon Relief Sun: Rice + Probiotics SPF50+; alternatives — SKIN1004 Centella Hyalu-Cica Water-Fit Sun Serum, Anua Heartleaf Silky Moisture SunCream, ROUND LAB Birch Juice Tone-Up Sunscreen.

Barrier-support moisturizer: primary — SKIN1004 Centella Probio-Cica Enrich Cream; alternatives — Dr.Althea 147 Barrier Cream, Beauty of Joseon Dynasty Cream, Anua Birch Moisture Boosting Cream.

Gentle cleanser: primary — SKIN1004 Centella Poremizing Deep Cleansing Foam; alternatives — Anua Heartleaf Quercetinol Pore Deep Cleansing Foam, SKIN1004 Centella Ampoule Foam, Beauty of Joseon Green Plum Refreshing Cleanser.

This is a conflict-solver for ACTIVE ingredients. If you run multiple actives, use these rules to avoid irritation, deactivation, and barrier damage.

Universal rules: run only one primary active lane per routine. If you break a rule, reduce frequency, split AM/PM, or alternate nights. If moisturizer stings or skin feels tight within 30 minutes of cleansing, pause all actives and run barrier-only for 3-7 days.

× Retinoids — not the same night; alternate nights or use skin cycling (Exfoliation/Azelaic night → Retinoid night → 2 Recovery nights).

× Other AHA/BHA (separate strong products) — avoid stacking two separate strong acids same night; alternate days instead.

× L-Ascorbic Acid (pure Vitamin C) — layering two low-pH actives increases irritation risk; classic split is AM Vitamin C / PM this Azelaic Acid Serum.

Scheduling templates: Template A (AM/PM Split) — AM Vitamin C + SPF, PM this Azelaic Serum. Template C (Alternate-Night) — Mon/Wed/Fri Azelaic Acid, Tue/Sat a separate retinol if tolerant, Thu/Sun Recovery.

Do not layer retinoids with AHA/BHA/azelaic acid in the same night; keep "one lane" per night.

Cycle awareness: pre-period (luteal phase) breakouts happen because progesterone causes the pore lining to physically swell, narrowing the opening and trapping sebum beneath (infundibular edema) — this azelaic acid serum can be maintained through this phase since its antibacterial and anti-clogging action is still relevant, though some users prefer to reduce frequency slightly if skin feels more reactive premenstrually.

Chronic stress elevates cortisol, which increases inflammatory acne and can worsen rosacea flushing. This serum's anti-inflammatory mechanism can help counter some of that effect, but it cannot address the underlying stress itself — sleep and stress management remain part of a complete approach to stress-linked breakouts.

MYTH: "Azelaic acid is unsafe during pregnancy like other acids." REALITY: azelaic acid is widely regarded by dermatologists as one of the pregnancy-compatible actives, unlike retinoids, high-dose salicylic acid, or hydroquinone — though anyone pregnant should still confirm with their own doctor.

MYTH: "If it doesn't sting, it's not working." REALITY: effective azelaic acid use should feel mild to no stinging after the first week or two — persistent burning is a sign to reduce frequency, not a sign of stronger results.

Mauritius tap water hardness varies by region; hard-water residue can compound irritation from this active — a pH-balancing toner before this serum is worth trying if stinging feels worse than expected.

Reformulation note: per the brand's own blog post, this AZ serum was updated to remove Witch Hazel and Eucalyptus Globulus Leaf (previously in the formula) at customer request, replacing them with green tea and other botanical extracts. This is a real, brand-confirmed reformulation.

Full INCI list: Aloe Barbadensis Leaf Extract, Propylene Glycol, Azelaic Acid, Polysorbate 20, 1,2-Hexanediol, Propanediol, Panthenol, Niacinamide, Sodium Hyaluronate, Camellia Sinensis Leaf Extract, Momordica Charantia Fruit Extract, Sambucus Nigra Flower Extract, Leontopodium Alpinum Extract. [--- Estimated 1% Line ---] Estimated after Sodium Hyaluronate — ingredients from Camellia Sinensis Leaf Extract onward are estimated (not brand-confirmed) to sit below 1%.

Preservative system: 1,2-Hexanediol (multifunctional preservative-booster/solvent).

Fragrance status: Fragrance-Free (no Parfum/Fragrance listed). Scent: likely faint/herbal from the green tea and other plant extracts. Intensity: estimated 1 out of 5. EU 26 allergen screen: none of the 26 named allergen molecules detected as standalone listings. Alcohol disclosure: Alcohol-Free (Propylene Glycol and Propanediol here are glycols, not drying alcohols).

Halal: *Self-assessed by Adilsons based on available INCI data. No ethanol, no porcine-derived ingredients, and no haram animal-derived ingredients detected in the declared list. This is NOT a formal Halal certification.

Vegan: *Self-assessed by Adilsons based on available INCI data. No animal-derived ingredients detected. This is NOT a formal vegan certification.

Cruelty-Free: *Brand-stated policy, not independently certified by Leaping Bunny, PETA, or equivalent audit.

Microplastic-Free: Yes.

MFDS Classification: not publicly confirmed. Clinical evidence: azelaic acid at 15-20% is an established prescription strength for acne and rosacea in some markets; this 10% cosmetic-grade version has real, well-documented ingredient-class evidence for acne, rosacea, and PIH, though this specific product's own trial data was not found. Evidence confidence: Medium-High for the ingredient class, Medium for this specific product's real-world results given the mixed independent reviews.

Fungal Acne Safety: FA-Conditional. Polysorbate 20 is a mild emulsifier some fungal-acne-prone users react to; azelaic acid itself is generally FA-safe.

Assessment: Low-Medium. Can pill if layered with a heavy silicone-based product the same routine — reduce layers or wait longer between steps.

Fresh appearance: clear to very pale. Storage: keep out of direct sun and away from prolonged heat above roughly 30°C. Spoilage signs: off smell, unexpected discoloration, or separation. When in doubt, discard.

Patch test: inner forearm for 24 hours, then behind the ear for 24 hours, then begin facial use at 2-3x/week. If adverse reaction: STOP ALL ACTIVES. For 72 hours, use ONLY gentle cleanser plus plain moisturizer plus mineral SPF — no acids, retinoids, Vitamin C, exfoliants, or essential oils. After 72 hours, reintroduce ONE product per 14 days. Emergency stop signals: hives, swelling, blistering, persistent burning, or breathing difficulty — seek emergency care.

1. Starting daily instead of building up from 2-3x/week. 2. Layering with another strong acid or retinol the same night. 3. Judging rosacea results too early — this varies more by individual than acne does. 4. Skipping SPF, undermining PIH-fading progress. 5. Assuming stinging means it's "working harder."

Volume: 30ml. Amount per use: pea-size (~0.4-0.5ml). Approximate uses per container: roughly 60-75 applications. Lifespan: at 3x/week use, approximately 5-6 months. Reorder roughly 2-3 weeks before you expect to run out.

This serum's job is multi-mechanism acne/redness/pigment support — it occupies the exfoliation/acne-control lane, never combined same-night with retinol or another strong acid. AM: cleanse → toner (optional) → Azelaic Acid Serum (if tolerated) → moisturizer → sunscreen. PM: cleanse → Azelaic Acid Serum → moisturizer.

If your skin is barrier-compromised right now: repair first before starting or resuming this. If you're new to azelaic acid: start with COS DE BAHA Azelaic Acid 5% Serum instead of this 10% version. If you have active acne AND dark spots: this single product addresses both, reducing the need to run two separate actives.

After purchasing, you will receive our skincare education email series covering this product in depth. The recommendations above are based on formulation synergy with this Azelaic Acid 10% Serum, not on margin or stock levels. If a pairing does not exist in our catalog, we say so. If you already own a product that fills the same role, use what you have first.

If 10% feels too strong or you're new to azelaic acid, COS DE BAHA Azelaic Acid 5% Serum is a real, in-stock, gentler alternative from the same brand.

Choose this 10% Serum over the 5% version if you need stronger acne/rosacea/PIH correction and have already established tolerance to azelaic acid.

Upgrade triggers: you've used the 5% version for 8+ weeks without irritation and want stronger results; your acne/PIH is more than mild. Do not upgrade yet if: your barrier is currently compromised; you are new to azelaic acid entirely; you experienced any irritation on the 5% version.

If you match 2 or more upgrade triggers above, this 10% version is worth choosing. If not, the 5% version is sufficient and safer. Consistency beats complexity.

A real strength ladder exists in this brand's catalog: COS DE BAHA Azelaic Acid 5% Serum (entry strength) → this 10% Serum (established tolerance) is the natural next step, generally after 8+ weeks of irritation-free use at 5%.

This product's PRIMARY function is: multi-mechanism acne, redness, and pigment support via azelaic acid. You do NOT need this if you already own another azelaic acid product, including the brand's own 5% version — finish that one first. Stacking assessment: No Benefit (same mechanism) if paired with another azelaic acid product; Significant Benefit if your current routine has no dedicated acne/rosacea/PIH-multi-pathway active.

This product is sourced through authorized Korean distributors — primarily Craver Co., Ltd (South Korea), alongside other verified distribution partners. Craver is a major Korean beauty distributor and the parent company of SKIN1004, handling authorized distribution for multiple K-beauty brands. All products are shipped directly to Mauritius via verified channels.

For comprehensive information about how we verify authenticity, our layered verification system, and how to check your product at home, visit our dedicated Authenticity and Trust page. Because a 5% version of this serum also exists, double-check the printed percentage on your box matches what you ordered.

Parent Company: JAINA Co., Ltd (CEO Junwon Lee). Founded: 2019. Headquarters: Suwon, South Korea. Manufacturing: contract manufacturing in South Korean laboratories the brand states are MFDS-certified.

COS DE BAHA positions itself as a value/high-potency actives brand, selling clearly-labeled single- and combo-active serums at accessible prices relative to prestige K-beauty actives brands. This azelaic acid serum sits alongside the brand's 5% version and its Salicylic Acid 4% Serum as its main acne-focused options.

Independent reviews for this exact product are mixed. One long-term (3-month) blog reviewer reported little change specifically for rosacea. Other reviewers praised it for visibly improving acne and fading post-acne dark spots, with one very-sensitive-skin user reporting no irritation, while another described occasional irritation and an oily feel, and one reported unexpected breakouts after a few uses (possibly purging, possibly a reaction — not distinguishable from the review text alone). These are presented as anecdotal accounts from iHerb reviews, an independent blog, and review aggregators rather than a single verified consensus.

Is azelaic acid safe during pregnancy? It is widely regarded by dermatologists as one of the pregnancy-compatible actives, but confirm with your own doctor before use.

Will this definitely help my rosacea? Independent reviews are mixed — some users see real improvement, others report minimal change. Individual response varies more for rosacea than for acne.

Can I use this with retinol? Not the same night — alternate nights or use the AM/PM split approach in the Conflict Solver section.

Why did the formula change? The brand's own blog confirms Witch Hazel and Eucalyptus were removed at customer request and replaced with green tea and other extracts.

Is 10% too strong for a beginner? Generally yes — start with the brand's 5% version first if you're new to azelaic acid.

Azelaic Acid

A naturally-occurring dicarboxylic acid used to treat acne, rosacea, and hyperpigmentation through several mechanisms at once.

Keratinization

The process of skin cell formation and shedding; azelaic acid helps normalize it to prevent clogged pores.

Infundibular edema

Pore-lining swelling caused by progesterone before menstruation, which traps sebum and can trigger breakouts.

PIH

Post-inflammatory hyperpigmentation — brown/tan marks from excess melanin.

Every product sold by Adilsons Beauty is 100% genuine, sourced through authorized Korean distribution channels. Full details on our verification system: Authenticity and Trust.

Our team is available to help you build a routine, troubleshoot reactions, and answer ingredient questions. WhatsApp: +230 5 778 2336.

For in-depth skincare education, visit our blog at adilsons.mu/blogs/k-beauty or subscribe to our email to get our guided education series delivered to your inbox.

Coverage: Island-wide delivery (Mauritius).

Processing and 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).

Express: May be available by region; request on WhatsApp: +230 5 778 2336.

Liquids/Sensitive Items: Serums, toners, liquid makeup (and kits containing liquids) are pickup or door-to-door only; checkout enforces this.

Scheduling: Deliveries run by region on set schedules; we will contact you the evening before.

Pickup: Citadelle Mall pickup available.

Returns: No change-of-mind exchanges.

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). Opened skincare/personal-care items are non-returnable (except if damaged on delivery).

Source of Truth: This is a quick snapshot. If anything differs, the policy pages are final.

Store Policies: For the most up-to-date information, please review our Shipping Policy and Refund Policy.

Best for: those with established acne, rosacea-related redness, or PIH who have already built tolerance to azelaic acid or are ready to start carefully. Key benefits: multi-mechanism action in one product, real brand-stated 10% concentration, dermatologist-regarded pregnancy compatibility. Keep in mind: independent reviews are genuinely mixed, especially for rosacea specifically; start low-frequency and never combine with retinol or another strong acid the same night.

Assessment: Consult Oncologist. While fragrance-free and retinoid-free, this is a 10% acid-strength active that may be too stimulating for treatment-sensitized skin without your care team's input. Consult your oncology care team before introducing any new active skincare products during treatment.

Quick scanner: Week 1-2 — introduce alone at 2-3 nights/week, monitor for excess stinging or breakouts. Week 3-4 — increase to daily if stable. Week 5+ — add one support product only if genuinely needed. If irritation occurs at any point, follow the 72-Hour Barrier Reset above.

This product must be introduced as the ONLY new product. Wait 14 days before adding anything else.