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Kosas Chemistry Deodorant Bo-Fighting Aha Serum Serene Clean

Chemistry Deodorant Bo-Fighting Aha Serum Serene Clean

Your pits need an aha moment. This is a stain-free serum deodorant with a unique blend of ahas for the ultimate bo-fighting treatment. Bonus points: soothes skin, visibly brightens, and helps with ingrown hairs. No aluminum. No baking soda. Only pit-nourishing ingredients allowed.
Uploaded by: amk on

Kosas Chemistry Deodorant Bo-Fighting Aha Serum Serene Clean
Ingredients explained

Also-called: Water | What-it-does: solvent

Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product. 

It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water. 

Also-called: Aloe Vera | What-it-does: soothing, moisturizer/humectant

Aloe Vera is one of today’s magic plants. It does have some very nice properties indeed, though famous dermatologist Leslie Baumann warns us in her book that most of the evidence is anecdotal and the plant might be a bit overhyped.

What research does confirm about Aloe is that it’s a great moisturizer and has several anti-inflammatory (among others contains salicylates, polysaccharides, magnesium lactate and C-glucosyl chromone) as well as some antibacterial components. It also helps wound healing and skin regeneration in general. All in all definitely a goodie. 

Glycerin - superstar
Also-called: Glycerol | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
  • A natural moisturizer that’s also in our skin
  • A super common, safe, effective and cheap molecule used for more than 50 years
  • Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
  • Effective from as low as 3% with even more benefits at higher concentrations up to 20-40% (around 10% is a good usability-effectiveness sweet spot)
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

Mandelic Acid - goodie
  • Mandelic acid is an AHA that comes from bitter almond
  • It can gently lift off dead surface skin cells and make the skin more smooth and even
  • It has antibacterial properties
  • It’s promising against acne and post inflammatory hyperpigmentation
  • It’s light sensitive, so choose a product with opaque packaging
Read all the geeky details about Mandelic Acid here >>

What-it-does: emollient, emulsifying

We don't have description for this ingredient yet.

Also-called: lye | What-it-does: buffering

The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right. 

For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.  

What-it-does: deodorant

We don't have description for this ingredient yet.

Lactic Acid - superstar
  • It’s the second most researched AHA after glycolic acid
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It also has amazing skin hydrating properties
  • In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
Read all the geeky details about Lactic Acid here >>

Also-called: Syn-Coll | What-it-does: cell-communicating ingredient

A tripeptide (three amino acids attached to each other: Lys-Val-Lys) that's claimed to protect and boost collagen and improve skin texture.

The manufacturer did an in-vivo (made on real people) study with 45 volunteers and found that used twice daily for 84 days 1% and 2.5% Syn-Coll reduces the appearance of wrinkles by 7 and 12% respectively. In another study (also by the manufacturer) with 33 female Chinese volunteers, 77% of the participants felt that Syn-Coll visibly improved the firmness and elasticity of the skin after 4 weeks. What's more, 60% of the participants also noticed a reduction in the look of the pore size also after 4 weeks of treatment. 

  • It’s naturally in our skin and behaves there like a sponge
  • It can bind up to 1000 times its own weight in water
  • It is a big molecule from repeated subunits (polymer) so different molecular weight versions exist (unfortunately there is no way to determine MW from INCI list only)
  • High-molecular-weight-HA (>500 kDa) is an excellent surface hydrator, skin protectant and can act as an osmotic pump helping water-soluble actives to penetrate deeper into the skin
  • Low-molecular-weight-HA (< 500 kDa) can hydrate the skin somewhat deeper though it is still a big molecule and works mainly in the epidermis (outer layer of the skin)
  • Low-molecular-weight-HA might also help the skin to repair itself by increasing its self-defense (~ 200kDa used in the study)
  • Ultra-low-molecular-weight-HA (<50kDa) is a controversial ingredient and might work as a pro-inflammatory signal molecule
Read all the geeky details about Hyaluronic Acid here >>

What-it-does: buffering

Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA. 

So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh. 

What-it-does: buffering, exfoliant

We don't have description for this ingredient yet.

It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range. 

Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415). 

What-it-does: preservative

It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It’s not a strong one and doesn’t really work against bacteria, but more against mold and yeast. To do that it has to break down to its active form, sorbic acid. For that to happen, there has to be water in the product and the right pH value (pH 3-4). 

But even if everything is right, it’s not enough on its own. If you see potassium sorbate you should see some other preservative next to it too.

What-it-does: preservative

A helper ingredient that helps to make the products stay nice longer, aka preservative. It works mainly against fungi. 

It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.

Also-called: Ylang Ylang Essential Oil | What-it-does: perfuming

Sweet, exotic and floral, it’ no surprise that Ylang Ylang is a popular essential oil. It is coming from the yellow, fragrant flowers of the Cananga tree native to tropical Asia and, similar to other essential oils, it is a chemically complex mixture with several pros and cons. 

Unfortunately, these are a bit tricky to pin down as the composition varies largely depending on where it is sourced, how the oil is extracted and the grade of it that is used in the product, but we’ll do our best!

Also-called: Bitter Orange Flower Oil, Neroli Oil

The essential oil coming from the flowers of bitter orange (which is the sister of the sweet orange we all know and eat). It contains several fragrance components including linalool (around 30%) and limonene (around 10%) and has a lovely sweet smell

As it's an essential oil with lots of fragrant components, be careful with it if your skin is sensitive.  

Also-called: Pink Grapefruit Peel Oil | What-it-does: perfuming

The essential oil coming from the peel of the pink grapefruit. In general, the main component of citrus peel oils is limonene (around 90% for grapefruit peel), a super common fragrant ingredient that makes everything smell nice (but counts as a frequent skin sensitizer). Similar to other essential oils, grapefruit peel has also antibacterial and antifungal acitivity

Other than that, citrus peels contain the problematic compounds called furanocoumarins that make them (mildly) phototoxic. So be careful with grapefruit peel oil, especially if it's in a product for daytime use.  

Also-called: Jojoba Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0-2

Jojoba is a drought resistant evergreen shrub native to South-western North America. It's known and grown for jojoba oil, the golden yellow liquid coming from the seeds (about 50% of the weight of the seeds will be oil).  

At first glance, it seems like your average emollient plant oil: it looks like an oil and it's nourishing and moisturizing to the skin but if we dig a bit deeper, it turns out that jojoba oil is really special and unique: technically - or rather chemically - it's not an oil but a wax ester (and calling it an oil is kind of sloppy). 

A common fragrance ingredient that has a faint sweet balsamic smell. It can also be a solvent and can fight against microbes and insects very well.

It's one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. Best to avoid if your skin is sensitive.

Limonene - icky
What-it-does: perfuming, solvent, deodorant

A super common and cheap fragrance ingredient. It's in many plants, e.g. rosemary, eucalyptus, lavender, lemongrass, peppermint and it's the main component (about 50-90%) of the peel oil of citrus fruits.

It does smell nice but the problem is that it oxidizes on air exposure and the resulting stuff is not good for the skin. Oxidized limonene can cause allergic contact dermatitis and counts as a frequent skin sensitizer

Linalool - icky
What-it-does: perfuming, deodorant

Linalool is a super common fragrance ingredient. It’s kind of everywhere - both in plants and in cosmetic products. It’s part of 200 natural oils including lavender, ylang-ylang, bergamot, jasmine, geranium and it can be found in 90-95% of prestige perfumes on the market. 

The problem with linalool is, that just like limonene it oxidises on air exposure and becomes allergenic. That’s why a product containing linalool that has been opened for several months is more likely to be allergenic than a fresh one.

You may also want to take a look at...

what‑it‑does solvent
Normal (well kind of - it's purified and deionized) water. Usually the main solvent in cosmetic products. [more]
what‑it‑does soothing | moisturizer/humectant
The famous aloe vera. A great moisturizer and anti-inflammatory ingredient that also helps wound healing and skin regeneration. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
A real oldie but a goodie. Great natural moisturizer and skin-identical ingredient that plays an important role in skin hydration and general skin health. [more]
what‑it‑does exfoliant | antimicrobial/antibacterial
An AHA that comes from bitter almond. Its exfoliation action is slower but also safer than glycolic acid. It's also antibacterial and is a promising ingredient against acne and post inflammatory hyperpigmentation. [more]
what‑it‑does emollient | emulsifying
what‑it‑does buffering
Lye - A solid white stuff that’s very alkaline and used in small amount to adjust the pH of the product.  [more]
what‑it‑does exfoliant | moisturizer/humectant | buffering
A superstar AHA that not only exfoliates skin but is also a very good moisturizer. In higher concentration (10% and up) it can even improve skin firmness, thickness, and wrinkles. [more]
what‑it‑does cell-communicating ingredient
Syn-Coll - An anti-aging tripeptide that's claimed to protect and boost collagen and improve skin texture. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
A famous natural moisturizing factor that can bind up to 1000 times its own weight in water. Works as an excellent surface hydrator in skincare. [more]
what‑it‑does buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [more]
what‑it‑does buffering | exfoliant
what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]
what‑it‑does perfuming
Sweet, exotic and floral, it’ no surprise that Ylang Ylang is a popular essential oil. It is coming from the yellow, fragrant flowers of the Cananga tree native to tropical Asia and, similar to other essential oils, it is a chemically complex mixture with several pros and cons. Unfortunately, these are a bit tricky to pin down as the composition varies largely depending on where it is so [more]
The essential oil coming from the flowers of bitter orange. Contains fragrant components that give it a nice sweet smell. [more]
what‑it‑does perfuming
The essential oil coming from the peel of the pink grapefruit. Its main component is limonene, a super common fragrant ingredient that makes everything smell nice. [more]
what‑it‑does emollient
irritancy, com. 0, 0-2
Jojoba oil - a wax ester (chemically not a real oil), that's very similar to human sebum. It's uniquely excellent at helping the skin with its protective barrier and helping it to stay moisturized. [more]
what‑it‑does solvent | perfuming | antimicrobial/antibacterial
A common fragrance ingredient that has a faint sweet balsamic smell. It can also be a solvent and can fight against microbes and insects very well. One of the “EU 26 fragrances” that has to be labelled separately because of allergen potential.
what‑it‑does perfuming | solvent
A super common fragrance ingredient found naturally in many plants including citrus peel oils, rosemary or lavender. It autoxidizes on air exposure and counts as a common skin sensitizer. [more]
what‑it‑does perfuming
A super common fragrance ingredient that can be found among others in lavender, ylang-ylang, bergamot or jasmine. The downside of it is that it oxidises on air exposure and might become allergenic. [more]