Kirkland Signature

Professional Salon Formula Moisture Conditioner

• 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 for dry skin at higher concentrations up to 20-40%
• High-glycerin moisturizers are awesome for treating severely dry skin

Propanediol is a natural alternative for the often used and often bad-mouthed propylene glycol. It's produced sustainably from corn sugar and it's Ecocert approved. 

It's quite a multi-tasker: can be used to improve skin moisturization, as a solvent, to boost preservative efficacy or to influence the sensory properties of the end formula. 

In itself, it's an antistatic (stops your hair from flying around because of electricity), hair conditioning and softening ingredient used mainly in haircare products. 

Coupled with Cetearyl Alcohol, they form an easy to handle, super stable emulsifier duo that has exceptional spreadability and gives a pleasant final touch to the products. 

We don't have description for this ingredient yet.

Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.

As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity. 

Expand to read more

A  clear, colorless and odorless, highly volatile (meaning it does not absorb into the skin but evaporates from it) liquid that's used as an emollient. It gives a nice non-oily light skin feel and it can improve the slip of the formula without leaving a tacky residue behind.

It's also popular in make-up products as its volatility makes mascaras and foundations last longer. If that would not be enough, it's also an excellent solvent, and it's a regular not only on the ingredients lists of make-ups but also on makeup removers.  

A light, velvety, unique skin feel liquid that is a good solvent and also makes the skin feel nice and smooth (aka emollient). It's often used in makeup products mixed with silicones to give shine and slip to the product. It's also great for cleansing dirt and oil from the skin as well as for taking off make-up.

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. 

Expand to read more

Exactly what it sounds: nice smelling stuff put into cosmetic products so that the end product also smells nice. Fragrance in the US and parfum in the EU is a generic term on the ingredient list that is made up of 30 to 50 chemicals on average (but it can have as much as 200 components!). 

If you are someone who likes to know what you put on your face then fragrance is not your best friend - there's no way to know what’s really in it.  

Expand to read more

A nice little helper ingredient that can thicken up cosmetic products and create beautiful gel formulas. It's derived from cellulose, the major component of the cell wall of green plants. It is compatible with most co-ingredients and gives a very good slip to the formulas. 

It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.

It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic. 

Expand to read more

It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol. 

The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.

A super common, waxy, white, solid stuff that helps water and oil to mix together, gives body to creams and leaves the skin feeling soft and smooth.

Chemically speaking, it is the attachment of a glycerin molecule to the fatty acid called stearic acid. It can be produced from most vegetable oils (in oils three fatty acid molecules are attached to glycerin instead of just one like here) in a pretty simple, "green" process that is similar to soap making. It's readily biodegradable.

Expand to read more

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

A modified dimethicone-type silicone molecule that also contains amino-groups. Having amino-groups means that Amodimethicone also has Nitrogen in its molecule that likes to have a positive charge. Positively charged (or quaternised) molecules are substantive to skin and hair as those are negatively charged surfaces and are excellent film formers. Amodiemthcone is no exception and it is especially recommended for hair-care products for its long-lasting hair conditioning benefits.

We don't have description for this ingredient yet.

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.

We don't have description for this ingredient yet.

A water-soluble, colorless, odorless humectant liquid that makes your skin nice and smooth (aka emollient) and gives a dry, non-tacky skin feel. It also has great instant and some longer-lasting moisturizing effect and works in synergy with fellow moisturizer, sorbitol. 

Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes.

It is typically used in tiny amounts, around 0.1% or less.

Unless you live under a rock you must have heard about shea butter. It's probably the most hyped up natural butter in skincare today. It comes from the seeds of African Shea or Karite Trees and used as a magic moisturizer and emollient.

But it's not only a simple emollient, it regenerates and soothes the skin, protects it from external factors (such as UV rays or wind) and is also rich in antioxidants (among others vitamin A, E, F, quercetin and epigallocatechin gallate). If you are looking for rich emollient benefits + more, shea is hard to beat. 

An amino acid-based emulsifier that helps water and oil to mix and stay that way. It is considered as natural, environmentally friendly, and hypoallergenic. 

Jojoba-derived emollient wax esters (fatty acid + fatty alcohol) that make your skin feel nice and smooth. Chemically speaking, pure jojoba oil is also a wax ester (read our shiny explanation here), however, the ingredients called jojoba esters on the ingredient lists are made from jojoba oil and/or hydrogenated jojoba oil via interesterification. 

They have multiple versions with variable fatty acid chain length and the ingredient can have a liquid, a creamy, a soft or firm paste, or even a hard wax consistency. The common thing between all versions is, that unlike most normal triglyceride oils, jojoba esters have superior stability, provide non-greasy emolliency and are readily absorbed into the skin. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

The acid found in vinegar. Can be a skin irritant and drying in larger amounts but in tiny amounts, it's used to set the pH of the cosmetic formula. Has also some disinfecting properties.

It's a nice glycerin-based humectant and emollient that gives skin a smooth and luxurious feel.

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.  

Expand to read more

We don't have description for this ingredient yet.

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.

Expand to read more

Sunflower does not need a big intro as you probably use it in the kitchen as cooking oil, or you munch on the seeds as a healthy snack or you adore its big, beautiful yellow flower during the summer - or you do all of these and probably even more. And by even more  we mean putting it all over your face as sunflower oil is one of the most commonly used plant oils in skincare.

It’s a real oldie: expressed directly from the seeds, the oil is used not for hundreds but thousands of years. According to The National Sunflower Association, there is evidence that both the plant and its oil were used by American Indians in the area of Arizona and New Mexico about 3000 BC. Do the math: it's more than 5000 years – definitely an oldie.

Expand to read more

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate is an antioxidant molecule used in small amounts (less than 0.8%) to help products stay nice longer. More specifically, it is great at preventing discoloration or other types of oxidative degradation. It is a trendy alternative to often bad-mouthed synthetic antioxidant and stabilizer, BHT. 

A type of lipid that's the major (about 75%) component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient.

It has a water-loving head with two water-hating tails and this structure gives the molecule emulsifying properties. It is also often used to create liposomes, small spheres surrounded by phospholipid bi-layer designed to carry some active ingredient and help its absorption.

When it comes to cosmetic oils and hype, argan oil is for sure leading the way. Dubbed as the "liquid gold of Morocco", we have to admit we have some trouble determining why this oil enjoys such a special miracle status. Not that it's not good, it is good, even great but reading the research about argan and a bunch of other plant oils we just do not see the big, unique differentiating factor (though that might be our fault not reading enough, obvs.)

So, argan oil comes from the kernel of the argan fruit that comes from the argan tree that grows only in Morocco. The tree is slow growing and getting the oil is a hard job. The traditional process is that the ripe argan fruits fall from the tree, then goats eat them up and poop out the seeds. The seeds are collected and smashed with a stone to get the kernels inside. This part is the hard one as the seeds have extremely hard shells. Once the kernels are obtained, the oil is pressed out from them (the kernels contain about 50% oil).

Expand to read more

The oil coming from the pulp of one of the most nutritious fruits in the world, the avocado. It's loaded with the nourishing and moisturizing fatty acid, oleic (70%) and contains some others including palmitic (10%) and linoleic acid (8%). It also contains a bunch of minerals and vitamins A, E and D. 

Avocado oil has extraordinary skin penetration abilities and can nourish different skin layers. It's a very rich, highly moisturizing emollient oil that makes the skin smooth and nourished. Thanks to its vitamin E content it also has some antioxidant properties. As a high-oleic plant oil, it is recommended for dry skin. 

• Works best between a concentration of 5-20%
• Boosts the skin’s own collagen production
• Fades pigmentation and brown spots
• If used under sunscreen it boosts its UV protection
• Extremely unstable and oxidizes very easily in presence of light or air
• Stable in solutions with water only if pH is less than 3.5 or in waterless formulations
• Vit E + C work in synergy and provide superb photoprotection
• Ferulic acid doubles the photoprotection effect of Vit C+E and helps to stabilize Vit C
• Potent Vit. C serums might cause a slight tingling on sensitive skin

It’s the most commonly used version of pure vitamin E in cosmetics. You can read all about the pure form here. This one is the so-called esterified version. 

According to famous dermatologist, Leslie Baumann while tocopheryl acetate is more stable and has a longer shelf life, it’s also more poorly absorbed by the skin and may not have the same awesome photoprotective effects as pure Vit E. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

• Primary fat-soluble antioxidant in our skin
• Significant photoprotection against UVB rays
• Vit C + Vit E work in synergy and provide great photoprotection
• Has emollient properties
• Easy to formulate, stable and relatively inexpensive

An easy-to-formulate, commonly used, nice to have ingredient that’s also called pro-vitamin B5. As you might guess from the “pro” part, it’s a precursor to vitamin B5 (whose fancy name is pantothenic acid). 

Its main job in skincare products is to moisturise the skin. It’s a humectant meaning that it can help the skin to attract water and then hold onto it. There is also research showing that panthenol can help our skin to produce more lovely lipids that are important for a strong and healthy skin barrier. 

Expand to read more

The emollient plant oil coming from the passion fruit. It is a high-linoleic acid oil (about 70% LA and 15% oleic acid), that makes your skin feel nice and smooth and supports a healthy skin barrier. As a high-LA oil, it is suitable for all skin types including acne-prone.

The emollient plant oil coming from the soybean. It is considered to be a nice, cost-effective base oil with moisturizing properties. As for its fatty acid profile, it contains 48-59% barrier-repairing linoleic acid, 17-30% nourishing oleic acid and also some (4.5-11%) potentially anti-inflammatory linolenic acid. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

The extract coming from the juice containing leaves of the Aloe vera plant. It's usually a hydroglycolic extract (though  oil extract for the lipid parts also exists) that has similar moisturizing, emollient and anti-inflammatory properties as the juice itself. We have written some more about aloe here.

• Green tea is one of the most researched natural ingredients
• The active parts are called polyphenols, or more precisely catechins (EGCG being the most abundant and most active catechin)
• There can be huge quality differences between green tea extracts. The good ones contain 50-90% catechins (and often make the product brown and give it a distinctive smell)
• Green tea is proven to be a great antioxidant, UV protectant, anti-inflammatory, anticarcinogenic and antimicrobial
• Because of these awesome properties green tea is a great choice for anti-aging and also for skin diseases including rosacea, acne and atopic dermatitis

Cucumber is a nice, non-irritating plant extract that’s known for it’s soothing and emollient properties. It’s not something new to put it on our face: even Cleopatra used it to “preserve her skin”.

It’s commonly believed that cucumber is the answer to puffy eyes, but there is no research confirming this. What research does confirm is that it contains amino acids and organic acids that’s helpful for the skin’s acid mantle. There is also an enzyme (called shikimate dehydrigenase) in the pulp that’s shown to have anti-inflammatory properties.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Simply alcohol refers to ethanol and it's a pretty controversial ingredient. It has many instant benefits: it's a great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial. No wonder it's popular in toners and oily skin formulas. 

The downside is that it can be very drying if it's in the first few ingredients on an ingredient list. 

Expand to read more

We wholeheartedly support the rise of seedless grapes as fruit snacks, but when it comes to skincare, we are big fans of the seeds.

They contain the majority of the skin goodies that -  similar to green tea - are mostly polyphenols (but not the same ones as in tea). The most abundant ones in grape are called proanthocyanidins, and 60-70% of them are found in the seeds (it's also often abbreviated as GSP - grape seed proanthocyanidins). In general, the darker the fruit, the more GSPs and other flavonoids it contains.

Expand to read more

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). 

A very common ingredient that can be found in all cell membranes. In cosmetics it's quite the multi-tasker: it's an emollient and water-binding ingredient but it's also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes. 

We don't have description for this ingredient yet.