Article by: Perry Romanowski

There was an interesting discussion on LinkedIn about whether Magnesium Laureth Sulfate was more gentle than Sodium Laureth Sulfate.  It’s a pretty good question and I’m not really sure about the answer.  Here is what my experience has been. SLES surfactant

Sodium and Ammonium

When I formulated at Alberto Culver we used SLS and SLES in our shampoos.  At the time about half of all the top selling shampoos used SLS/SLES.  The other half used ALS/ALES (ammonium lauryl sulfate / ammonium laureth sulfate).  This included brands like Suave, Finesse, and Salon Selectives.  What it really boiled down to was that P&G, who had many of the top shampoos, used SLS/SLES and Helene Curtis, who eventually became Unilever and had many other top shampoos, used ALS/ALES.  Since I worked on the VO5 brand we typically compared our performance to Suave which was similarly positioned.  This was convenient because they used ALS/ALES and we used SLS/SLES.

In all the testing I did there wasn’t much difference in performance.  We were not able to demonstrate any customer preference of the shampoos in home use tests and we couldn’t find any foaming or combing differences in lab tests.  As far as my testing went, I couldn’t tell a difference between the counterion used in the surfactant.    So, at least in my experience, there really is no noticeable performance difference between an ammonium based surfactant and a sodium based one.

As far as irritation goes, the CIR concluded that while both have the potential to be irritating to skin, they can be formulated to be non-irritating.

I would be curious if anyone could direct me to research that shows differently.

Other counterions

In the discussion the original question was about Magnesium Laureth Sulfate.  This isn’t an ingredient I’ve ever used.  It was commonly believed by responders in the thread that MLES is less irritating to the skin than SLES.  However, according to this research ( Paye, Zocchi, Broze XXVII Jornadas Anuales CED Barcelona, Spain, June 1998, pagg.449-456) there is no difference in skin irritation when tested in-vivo on human subjects.

So, I can’t think of any good reason to choose one of these types of surfactants over the other except when it comes to questions of supply and pricing.  The reason we used SLS/SLES was not because it was superior to ALS/ALES.  It was only because we were able to get a better price break on the sodium surfactant.  I suspect that the reason Helene Curtis used ALS was because they got a better price on the ammonium surfactant.

Sometimes that is all it takes to choose one raw material over another.

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5 comments

  1. EM

    Many manufacturers provide information regarding magnesium LES as less irritant compared to SLES or ALES. I don’t think the information they provide is fake. The research you mentioned is very obscure IMO, they don’t give any information about the invivo study, at last I couldn’t find anything.
    It is not always about prices when choosing surfactants, or fillers in solid formulation, it is about substance compatibility, formulation, time, manufacturing, accessibility etc. The price of surfactants is dirt cheap (we are talking about less less 1-3 eur/usd per kg) which translates into almost nothing in the final product. API or active ingredients are usually those which increase the price of the shampoo (and packaging). So choosing a surfactant only because of price and not consider every other factor is not a smart move.
    Why would you use SLS or ALS in a shampoo? Wasn’t SLES or ALES enough as the main surfactant?

    1. Perry Romanowski

      For many formulators, SLES and ALES do not foam well enough.

      1. EM

        In that case an addition of other co-surfactants is what is needed, something like CAPB, disodium laureth sulfate etc, SLS and ALS are too aggressive for scalp and hair.

  2. Randy Schueller

    I agree that there’s little to no consumer detectable performance difference based on the cation. However, we did find that in certain shampoo systems we could achieve better low temperature clarity with ALS vs SLS. The SLS systems would become hazy while the ALS systems stayed crystal clear. The hypothesis for this was related to how the different counter ions affected the way the surfactant molecules packed together. We were even granted a patent for this novel discovery. (BTW, the manufacturing team claimed that the ALS was MUCH more corrosive to their stainless steel tanks and we eventually had to move away from ALS.)

    1. Perry Romanowski

      That’s right, I recall the corrosive issue. Now that you mention it, I also recall that ALS patent thing. Thanks for reminding me. I’m pretty sure there are probably some differences but probably no consumer perceptible ones.

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