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Shampoo Surfactants
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Hi! I'm new here but I'm definitely not new to the beauty brains website - I absolutely love it! I am now completely obsessed.
I have a question about surfactants used in shampoos. I've done a little bit of research on them and understand that there are anionic, cationic, nonionic and amphoteric surfactants. From what I understand (please correct me if i'm wrong) shampoos mostly use anionic surfactants like sodium laureth/lauryl sulfate or ammonium laureth sulfate or magnesium laureth sulfate to clean the hair.... now here comes my question and it's been bugging me for ages... which anionic surfactants are the most harsh on hair and which ones are the mildest? Is ammonium laureth sulfate harsher on hair (and more foamy) than sodium laureth sulfate or magnesium laureth sulfate? Which are the most gentle surfactants to use in shampoo?
Also, i noticed that some shampoos use more than one type of surfactant.. does this mean they're harsher on hair?
I'd really appreciate ANY help i can get on this because the internet hasn't been as helpful on this topic as i thought it might be. -
Ah, this is a bit of a complicated question.
First, there really haven't been any published studies comparing all surfactants but generally the most "harsh" surfactants are Ammonium Lauryl Sulfate (ALS) and Sodium Lauryl Sulfate (SLS). Surfactants denoted by the term "laureth" like SLES & ALES are slightly less harsh than ALS & SLS. In fact, surfactant suppliers always compare the harshness of their new products to SLS.
The most gentle surfactants to use are nonionics.
The part of mixing surfactants is where things get more complicated. You could use a harsh surfactant like SLS but then use a secondary surfactant to reduce irritation & harshness. So, a crafty cosmetic chemist could even make gentle shampoo that uses SLS. Harshness depends on these three things.
1. Type of surfactant
2. Concentrations used
3. Mixture of secondary ingredients to off-set harshness
Hope that helps. -
Wow! A response from the Left Brain herself! Thanks Left Brain!
I never knew that by adding other milder surfactants to the harsher surfactants in the shampoo it can actually off-set harshness. That explains a lot! Brilliant.
And about the "laureth" part - thanks for the heads up.
So that explains why that whilst the ingredients of Pantene Pro V shampoo contains Ammonium Lauryl Sulfate as a second ingredient, the fact that it contains Ammonium laureth sulfate as a third means that it's not as harsh as a shampoo with only ammonium laurly sulfate as a surfactant.
So does that mean that a shampoo like Kerastase Bain Satin with the ingredients list below is slightly more mild than Pantene Pro V for example?? I ask this because i notice that it only contains sodium laureth sulfate as a surfactant (unless of course disodium cocoamphodiacetate is also a surfactant, is it an amphoteric one possibly?).
I'm just dying to know which shampoos are going to be more gentle on my hair without me having to buy baby shampoo or shampoos that advertise themselves as "SLS and SLES free". Could you help me with this?
Thanks for all your help.
ps. i forgot to list the ingredients for Kerastase Bain Satin Shampoo. Here it is...
water, sodium laureth sulfate, disodium
cocoamphodiacetate, sodium chloride, cocamide mipa, glycol disterate,
polyquaternium 10, hexylene glycol, disodium ricinoleamido
mea-sulfosuccinate, tartaric acid, sodium methylparben, dmdm
hydantoin, carbomer, methylparben, fragrance/ parfum
Is there anywhere I can find a list of all the anionic surfactants used in shampoos put in order of harshness? -
Based strictly on the ingredient lists, the Kerastase shampoo would be more gentle than the Pantene Pro V. Of course, without seeing the actual formulas (amounts) and method of production, I can't really know for certain. But I'm about 90% sure the Kerastase will be more gentle.
You are correct that disodium cocoamphodiacetate is a detergent. It's actually an amphoteric surfactant (SLS is an anionic one) that is much less irritating. The reason it is not used as the only detergent is because it wouldn't foam nearly as well and it would make the formula much more expensive.
Unfortunately, there is no simple list of anionic surfactants in order of harshness. Again, it depends a bit on the formula.
But the most harsh are ALS & SLS. Slightly less harsh are SLES & ALES. In general, formulas that don't have these ingredients or are not listed high on the ingredient list will be less irritating and likely more gentle.
If I find a good list like the one you've asked about, I'll write it up here.
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Thanks Left Brain! I really appreciate all your help on this.
I was looking up some of the Alterna shampoos and was investigating their "Sulfate free" claims. When looking at the ingredients for Alterna Caviar Anti-Ageing Moisture Shampoo, I spotted that their first two surfactants were Sodium Cocoyl Isethionate and Sodium Lauryl Sulfoacetate. I know that the Sulfosuccinates are generally milder than the sulfates but I was wondering whether the above two ingredients are considerably milder than SLS or SLES? Are they too amphoteric or are they non ionic?
Is it really worth paying quite a bit for these Alterna products when I can wash my hair with a gentle conditioner with not that many silicones in it? I've used the schwarzkopf smoothie yoghurt aloe vera conditioner to clean my hair before. It works surprisingly well but I have to leave it in for a long time at the roots.
ps. here is the ingredients list for Alterna Caviar Anti-Ageing Moistue Shampoo
http://www.skinstore.co.uk/Alterna-Caviar-Anti-Ageing-Moisture-Shampoo
thanks for all your help!
Also, is Cocamidopropyl Betaine a zwitterionic surfactant? Are zwitterionic surfactants milder than other surfactants? I noticed that a lot of shampoos seem to use it... i previously thought that it was like a conditioning agent or something that served as an anti-static agent in hair conditioners. I read somewhere that it's now starting to replace Cocamide DEA in shampoos - is this a good thing? Why is this happening?
sorry for all the questions! -
The two ingredients you listed are likely milder than SLS but that doesn't mean the shampoo will be milder. You can create a mild shampoo using SLS and a more harsh one using Sodium Cocyl Isoethionate. It all depends on what else is in the formula. The only way you can really tell is to use each shampoo and see how it behaves on your hair.
No, it's not worth paying a lot for a shampoo. There is very little difference between most. If you use a conditioner (as you should) the shampoo doesn't matter at all.
Yes, Coco Betaine is zwitterionic and can become a cationic surfactant at some pH levels and an anionic surfactant at others. -
Thank you for all your help on this Left Brain - I really appreciate it!
I love reading about this! This website has really helped me become more product aware.
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