There are SO many cleansers used in shampoos, how can you tell which ones are the mildest? Tune in this week as Randy and I teach you how to find a gentle shampoo.
Show notes
Beauty Science News
- New developments in sunscreen: first Cloud Guard, now Tattoo Guard.
- UV camera shows sun damage.
- Mineral sunscreens may be toxic to our oceans.
- 4 reasons beer based shampoos are just silly.
Question of the week: How do you choose a mild shampoo?
Alexandra asks…I have been trying to find more delicate shampoo because my hair is baby fine and prone to breakage. I know laureth is better than lauryl but is it the best? What about coconut based detergents in natural products. I’d love to be able to tell how harsh a shampoo is just from the list of ingredients.
What does mildness mean?
“Mild” can mean different things to different people.
- Does “mild” mean the product shouldn’t irritate skin? Then you will want classic gentle, ingredients.
- Or does “mild” mean it won’t sting your eyes? In that case you need something that’s not only gentle to skin but that’s proven to be non-stinging to eyes, as in baby shampoos.
- Or, as Alexandra asked, are you worried about fine hair which can break easily? Then you might need extra conditioning to provide mildness.
- She also might want a shampoo that lathers as quickly and thoroughly as possible so she doesn’t have to spend a lot of time scrubbing her hair to get it cleaned which can cause more breakage. In that case a shampoo which produces lather very quickly maybe important to her.
As you can see depending on what you’re looking for in a “mild” shampoo may determine what type of product we would recommend.
So why don’t cosmetic chemists just make one type of formula that suits all these goals. Why not make it high foaming AND fast foaming, AND mild to skin AND to eyes AND very conditioning – why not just put all that together into one product? The answer is – it’s a little more complicated than you might think.
Why chemists pick one surfactant over another
As in the case with most cosmetics, it’s a question of trade offs. Yes some ingredients are milder than others – but there are always multiple goals you’re trying to achieve when you make any formulation. If your goal is to produce the mildest formula period, then yes of course you should use the gentlest ingredients. But what if your goal is to also make the shampoo foam really well? The mildest ingredients don’t always foam well – so that’s a problem. And you’ll also have cost constraints which limit which ingredients you can use. If your goal is to produce the cheapest formula, then no. So as chemists it’s our job to do the best we can in balancing all these parameters to deliver a product that meets the goals. Here are a few of things we measure when we formulate a mild shampoo:
- Irritantcy
- Foam height
- Foam texture
- Flash foam (speed of foaming)
- Detergency – how well it cleans. A shampoo may be very gentle but if you have to wash your hair three times to remove styling residue the net result will be more damage to your hair.
- Processing considerations – we tend to think of the consumer is driving all the important product attributes however this is not necessarily the case. I think you would be surprised to find out how much the manufacturing side of a company how much input they have on what goes into a formula.
- Compatibility with other ingredients – strong anionics like sulfates don’t play well with conditioning agents. Sal acid needs low pH which some surfactants don’t like.
- Color
- Odor
- Purity – trace amounts of things can that mess up the formula like too much salt.
Natural considerations (sourcing/biodegradability etc)
So the point of all this is just to recognize that there is a lot more involved in picking a good surfactant beyond its mildness.
Lower cost cleansers that are more likely to irritate
These are the most commonly used surfactants because they clean well and they’re cheap. However, they are also more likely to irritate skin and strip hair.
- Sulfates (regular): Sodium lauryl sulfate, ammonium lauryl sulfate, TEA lauryl sulfate
Excellent foamers and degreasers. However sulfates do tend to bind to skin protein which means they don’t rinse very well. This can lead to irritation for some people. - Ether Sulfates (ethoxylated): Sodium laureth sulfate, Ammonium laureth sulfate, Sodium trideceth sulfate
Milder than regular sulfates but don’t foam as well. - Alpha Olefin Sulfonates: Sodium C12-14 Olefin Sulfonate, Sodium C14-16 Olefin Sulfonate
One of the most commonly used surfactants in the world (not just in shampoos) because they’re low priced, high foaming, all purpose surfactants. In terms of mildness they about the same as the ether sulfates.
Mildness boosters (can be added to lower cost cleansers to reduce irritation)
This is the list of ingredients that can make an SLS or SLES based shampoo much more tolerable because these can mitigate irritation. They can “plus up” a cheap surfactant to give you a milder product
- Amine oxides: Cocamidopropylamine oxide
These have excellent oily soil removal properties. Are used as foam boosters. They not only improve the amount of foam but also the quality of its structure. They have the bonus feature of providing some conditioning to hair that persists after rinsing. - Betaines: Cocamidopropyl betaine
Betaines are effective cleansers, they are also foam boosters and thickeners. They can also reduce irritation of other surfactants. Good value for the money. - Glutamates: Sodium lauroyl glutamate, sodium cocoyl glutamate
Made glutamic acid. Very mild but don’t lather very well. - Glycinates: Sodium cocoyl glycinate, potassium cocoyl glycinate.
Glycinates are made from the amino acid glycine. These are mild because they have good skin compatibility. (Not irritate like SLS). They even show some hair conditioning properties. However they’re not stable in hard water so unless you have soft water you probably want to stay away from formulas containing glycinates. - Sarcosinates: Sodium Lauroyl Sarcosinate
Sarcosinates are made from yet another amino acid called sarcosine which is also known an n-methyl glycine. Similar mildness and foaming profile. However, some people have gotten contact dermatitis from hand soaps using this stuff. - Sulfoacetates: Sodium lauryl sulfoacetate
Although it seems to be a “safer” alternative to sodium lauryl sulfate, it still does pose the risk of skin irritation. Additionally, it’s not an environmentally-friendly option, as it takes a long time to bio-degrade and does pollute aquatic ecosystems. - Sulfosuccinates: Disodium laureth sulfosuccinate, CocamidMEA Sulfosuccinate
This mildness booster gives high foam but it doesn’t do much to build viscosity. It is mild but has some restrictions around pH so this is another one that you can’t use in sal acid systems. - Sultaines: Cocamidopropyl hydroxysultaine, lauramidopropyl hydroxysultaine
Give great foam at low pH and can improve the mildness of harsher detergent systems. Also good for dispersing lime soap so if you have some bath rub ring, it will help with that whereas some surfactants will just make the problem worse. - Taurates: Sodium methyl cocoyl taurate
Another amino acid based surfactant, this one based n-methyltaurine.
Higher cost/proven to be most mild
These are the premium cleansers that are the most mild and which are typically used in the most expensive products.
- Amphoacetates (Amphoterics):Sodium Cocoamphoacetate
At normal use levels amphoacetates are non-stinging to the eyes which is why they’re used in baby shampoos. While you may see this listed as the first surfactant, it’s typically not the only one. It still needs to be coupled with other surfactants to provide optimal performance. (for example, it doesn’t thicken easily.) Having said that, it does have good lather, it’s gentle, and it provides some conditioning to hair. It also biodegrades easily which is a bonus. - Glucosides: Decyl Glucoside
These are formally known as Alky Polyglucosides. While these are certainly synthetic materials they are often considered natural because the alkyl part can be made from coconut oil the glucoside part is typically corn derived. It’s non-ionic (one of the reasons it’s mild) – the more glucose units it contains, the milder it is. It also has pretty decent foam. It’s typically used with a betaine to thicken and boost lather. Benefit is that it’s completely free from any kind of ethoxylation which can lead to dioxane contamination. - Isethionates: Sodium cocoyl isethionate, Sodium lauroyl methyl isethionate
Our favorite mild surfactant – the isethionates. Multiple studies have shown them to be extremely mild to skin and it produces a really creamy lather. The “isethionate” part comes from isethionic acid which is a type of sulfonic acid – so this is related to the sulfonates we talked about earlier. It can be irritating to eyes at higher concentrations so you won’t see this used much in baby shampoos but other than that we consider it to be the gold standard for mild surfactants.
Four tips to pick a mild shampoo
- Avoid anything with “sulfate” and “sulfonate”
- Look for Isethionate or Glucoside as the first ingredient after water
- Look for Mildness boosters such as sulfosuccinates, sultaines, amphodiacetates
Look for conditioning ingredients like silicones, polyquaterniums, and “guar”
Finally keep in mind that fragrance can be irritating and that no matter how hard you look for a mild product that can be an issue that you can’t screen for by looking at the ingredients.
Buy your copy of It’s OK to Have Lead in Your Lipstick to learn more about:
- Clever lies that the beauty companies tell you.
- The straight scoop of which beauty myths are true and which are just urban legends.
- Which ingredients are really scary and which ones are just scaremongering by the media to incite an irrational fear of chemicals.
- How to tell the difference between the products that are really green and the ones that are just trying to get more of your hard earned money by labeling them “natural” or “organic.
Click here for all the The Beauty Brains podcasts.