Cos De Baha Serum Products in Bangladesh

Cos De Baha is a Korean skincare label built almost entirely around single-active serums, each named for what is in it rather than for what it promises.

Most of the range is filed under Serums & Ampoules. The sections below group it by active, and explain the two-letter codes that make the names hard to tell apart.

Azelaic Acid

• Cos De BAHA AZ Azelaic Acid 10 Serum 30ml — looked up far more than anything else in the range.
• Cos De BAHA A5 Azelaic Acid 5 Serum and Cos De BAHA AZ15 Azelaic Acid 15% MSM Serum
• Cos De BAHA AC Azelaic Acid Hinokitiol Clear Skin Serum 30ml and Cos De BAHA AZ20 Azelaic Acid MSM Cica Facial Cream 50ml

Most of the demand that reaches this brand is for azelaic acid, and the range carries it across a spread of strengths in both a serum and a cream.

The number in the name is the strength

A5 is the gentlest of them and the numbers climb from there. Starting at the top of the range because it sounds more effective is the usual mistake, and it tends to end in irritation and a product left unused.

Skin that has not met azelaic acid before does better starting low and building up, which is also how it is used in clinical practice.

It suits skin that reacts to other actives

Azelaic acid is generally better tolerated than the stronger exfoliating acids and is one of the few options usually considered acceptable in pregnancy. That is a question for a doctor rather than for a product page, but it is why it comes up.

Expect stinging in the first days, and expect it to settle. Expect several weeks before any change in pigmentation is visible.

What the Two-Letter Codes Mean

Every product here is named with a short code before the ingredient — AZ, AN, TN, RS, VM, S2. The code is how the brand distinguishes formulas that would otherwise have near-identical names, and it is what people end up searching.

Read the code as an abbreviation of the actives

AN is arbutin with niacinamide, TN is tranexamic acid with niacinamide, TT is tranexamic acid on its own, S2 and S4 are salicylic acid at two strengths, and RS and RT are the two retinol formulas. The pattern holds across the range once you see it.

Where a first letter recurs, the products usually share an active and differ in what is paired with it or in strength.

Check the code before ordering, not the front of the bottle

The bottles look alike and the codes are small. Two serums a shelf apart can be the same active at very different strengths, which matters a great deal if one is being repurchased.

Brightening and Pigmentation

• Cos De BAHA TN Serum with Tranexamic Acid Niacinamide and Cos De BAHA TT Tranexamic Acid 10 Serum
• Cos De BAHA AN Serum with Arbutin Niacinamide 30ml and Cos De BAHA AL A- Arbutin 5% Licorice Serum
• Cos De BAHA LS Lactic 12.5% Serum — under Brightening Serum.

What the ingredients genuinely do. Arbutin, tranexamic acid, niacinamide and licorice act on the pigment-making step in the skin. Used consistently, they can fade dark marks left by acne, patches of melasma and sun-induced pigmentation, and they can slow new marks forming.

What they do not do. They do not change the colour you were born with. Melanin is not a blemish and no serum alters the skin’s baseline tone; what these products act on is the excess pigment in a specific patch, not the skin overall.

What actually decides the result. Daily sunscreen, and months rather than weeks. Pigmentation is driven by ultraviolet exposure, so a serum used without sun protection is working against something stronger than itself. Melasma in particular recurs readily and is a condition to see a dermatologist about.

Pick one and give it time

Layering four pigmentation serums does not speed anything up, and it makes irritation likely and the cause of it impossible to identify. One product, used morning and night as directed, for a full season.

Photograph the area in the same light every few weeks. Gradual change is close to invisible in the mirror.

Hydroquinone Is a Course, Not a Routine

Cos De BAHA HB Hydroquinone Brightening Serum 30ml is the one product in this range that needs treating differently from the rest.

It is used for a defined period and then stopped

Hydroquinone is a medical skin-lightening agent, not a cosmetic ingredient, and it is regulated as such in many countries. It is prescribed in courses of limited length with breaks in between, and it is not something to keep in a routine indefinitely.

Prolonged continuous use is associated with ochronosis, a bluish-grey darkening of the treated skin that is difficult to reverse — the opposite of the intended effect.

See a dermatologist before starting it

The dose, the length of the course and whether it suits your skin at all are clinical questions. Avoid it in pregnancy and while breastfeeding, keep it off broken skin, and stop and seek advice if the area darkens or becomes persistently inflamed.

Sunscreen is not optional alongside it. Treated skin is more vulnerable to ultraviolet light, and without protection the course undoes itself.

Exfoliating Acids

• Cos De BAHA S2 Salicylic Acid BHA 2% Liquid and Cos De BAHA S4 Salicylic Acid BHA 4% Serum
• Cos De Baha G Glycolic Acid 10 AHA Serum

Under Acne Fighting Serum.

BHA and AHA are not the same job

Salicylic acid is oil-soluble, so it gets into the pore and suits congestion, blackheads and oily skin. Glycolic and lactic acid work on the surface and suit texture, dullness and shallow marks.

Twice a week to begin with

Acids are the group most often overused. Tightness, stinging on application and a shiny, fragile look are signs of a damaged barrier, not of progress.

Build the frequency up over weeks, and stop entirely for a while if the skin starts reacting to things that never bothered it before.

Retinol and Bakuchiol

• Cos De Baha RS Retinol 2.5 Serum 30ml and Cos De Baha RT Retinol Tranexamic Acid Cica Serum 30ml
• Cos De BAHA L2 Serum with Level 2 Bakuchiol 2% and Retinol 0.5% 30ml — under Retinol.

Night only, and not with an acid on the same evening

Retinol degrades in light and increases sun sensitivity, so it belongs in the evening routine. Stacking it with an exfoliating acid on the same night is the most common cause of the peeling that makes people give up.

Alternate the nights instead, and use a plain moisturiser on the nights in between.

Avoid retinol in pregnancy

Vitamin A derivatives are avoided in pregnancy and while trying to conceive. If you are unsure whether that includes a product you already own, take the bottle to a doctor rather than reading the front of it.

Bakuchiol is often chosen as a gentler alternative, though a formula that pairs it with a retinoid is not one — the name on the listing states what is in it.

Niacinamide, Peptides and Vitamin C

• Cos De BAHA (N) Niacinamide 10 Serum 30ml and Cos De BAHA GN Galactomyces 94 Serum
• Cos De BAHA P Peptide M.A Serum 30ml and Cos De BAHA NN NMN 10 EGF FGF Peptide Serum
• Cos De BAHA VM Vitamin C MSM Serum and Cos De BAHA VA Serum with Vitamin C 15% and Ascorbic Acid

Under Multi Functional Serum.

Vitamin C goes in the morning, under sunscreen

It works alongside sun protection rather than instead of it. Pure ascorbic acid also oxidises once opened — a serum that has turned deep orange or brown has degraded, and the colour is the only warning you get.

High-percentage vitamin C is not automatically better

Above a certain concentration the extra does little and the irritation rises. Skin that stings with a strong formula is usually better served by a lower one used every day than by a stronger one used occasionally.

Hyaluronic Acid, Ceramides and Creams

• Cos DE BAHA H Hyaluronic Acid Serum
• Cos De BAHA PC M.A. Peptide Cream — under Barrier Repair Cream.

Further hydrating serums and moisturisers sit under Cream & Moisturizer.

Apply hyaluronic acid to damp skin and seal it

It draws water, so on dry skin in dry air it can pull moisture out of the skin rather than into it. Apply to a face that is still damp and follow with a moisturiser.

The moisturiser is what holds everything else together

A routine built entirely from actives, with nothing to repair the barrier, is the pattern behind most irritation. A plain cream is not the exciting part of the shelf and it is the part that lets the rest be tolerated.

Introducing an Active

Patch test, and add one thing at a time

Try a small amount on the inner forearm or behind the ear for a few days before it goes on the face. Then introduce one new product, wait a fortnight, and only then consider another.

Starting three serums in one week means that if something reacts, there is no way to know which.

Combinations worth avoiding at first

Retinol with an exfoliating acid on the same night, two acids together, and a full pigmentation routine layered over either. None of these is forbidden, but none is where to begin.

If skin becomes red, tight or newly sensitive, stop everything except a plain moisturiser until it settles.

Sunscreen Decides the Result

This applies to every section above and it is the part most often skipped. Pigmentation is driven by ultraviolet exposure, exfoliating acids and retinol both increase sensitivity to it, and hydroquinone undoes itself without protection.

Daily, on every exposed area, reapplied through the day. Without it, a pigmentation routine is spending money to stand still.

Where Cos De Baha Sits on Arogga

This page collects one brand. The shelves collect one kind of product across brands, which is the comparison to make when a particular active is wanted and this range does not carry it.

Formulations and stock change, so the listing is the record for both.

About Cos De Baha

Cos De Baha is a Korean skincare brand whose range is built around single-active serums at stated concentrations, sold in plain packaging with the active named on the bottle. It is the approach that made the label recognisable outside Korea.

The range here is dominated by serums, with a smaller set of creams and moisturisers. Azelaic acid draws more interest than anything else, followed by the vitamin C and tranexamic acid formulas.

It is also written Cosmetique de Baha, and searched as Cos Debaha, Cos Baha and simply Baha. All of them are the same brand.

Frequently Asked Questions

1. What do the two letters in the product names mean?

They abbreviate the actives. AN is arbutin with niacinamide, TN is tranexamic acid with niacinamide, S2 and S4 are salicylic acid at two strengths, RS and RT are the two retinol formulas. Products sharing a first letter usually share an active and differ in strength or in what is paired with it.

2. Which azelaic acid strength should I start with?

The lowest. The number in the name is the strength, and skin that has not met azelaic acid before does better starting low and building up. Starting at the top because it sounds more effective usually ends in irritation and an unused bottle.

3. Will these serums lighten my skin tone?

No. They act on excess pigment in a specific patch — acne marks, melasma, sun-induced pigmentation — not on the skin’s baseline colour, which no serum changes. Results depend on daily sunscreen and on months rather than weeks.

4. Is hydroquinone safe to use long-term?

No, and it is not meant to be. It is a medical agent used in courses of limited length with breaks between them. Prolonged continuous use is associated with ochronosis, a bluish-grey darkening that is hard to reverse. See a dermatologist before starting it.

5. Can I use retinol and an exfoliating acid together?

Not on the same night, at least at first. It is the most common cause of the peeling that makes people abandon retinol. Alternate the nights and use a plain moisturiser in between. Retinol is also avoided in pregnancy and while trying to conceive.

6. Why does my hyaluronic acid serum make my skin feel tighter?

Because it draws water, and on dry skin in dry air it can pull moisture out rather than in. Put it on while the face is still damp and seal it with a moisturiser. That one step is usually the whole difference.

7. My vitamin C serum has turned orange. Can I still use it?

It has oxidised and is past its useful life. Pure ascorbic acid degrades once opened, and the colour change is the only warning you get. Keep it capped, out of sunlight, and use it within a reasonable time of opening.