It's so good at what it does that olefin sulfonate actually cleanses better than the sulfate most commonly used in shampoos today, sodium laureth sulfate (SLES). But that's not a good thing.
Sodium laureth sulfate has all but replaced sodium lauryl sulfate in sulfate shampoos.
The 'eth' in its name is the clue; sodium laureth sulfate is chemically modified, 'ethoxylated' to be milder than the harsh sodium lauryl sulfate which sparked the whole sulfate backlash.
Olefin sulfonate is every bit as harsh as the original sodium lauryl sulfate.
The level of clean delivered by both olefin sulfonate and sodium lauryl sulfate is unnecessary for cleansing hair, even if you use tons of greasy oils and butters or hard-to-remove silicones like cyclopentasiloxane.
Sodium laureth sulfate is enough to get these out without completely stripping your hair. Sodium lauryl sulfate and olefin sulfonate, on the other hand, are so eager to remove oil and grease they burrow into your strands after them, leaving holes in your hair shaft.
And while all the added oils and fatty alcohols can stop your hair from feeling frazzled when you're using your olefin sulfonate-based shampoo, at a strand level, this ingredient can still do all the damage that sodium lauryl sulfate does, can since its molecules are around the same size.
Point blank: Just because a shampoo says sulfate-free doesn't mean that it's milder or gentler or better for your hair.
Are sulfate-free shampoos bad for your hair?
Keep this in mind: the only way to tell if a shampoo, sulfate-free or otherwise, is good for your hair is to look at the whole formulation. At the very least, that means a)making sure that key drying ingredients aren't there, so no sodium lauryl sulfate, ammonium lauryl sulfate, olefin sulfonate, or salt (sodium chloride) on the ingredients list, and then b) trying it out and seeing what it does to your hair.
Formulations work as a whole, and the exact amount of each ingredient is not stated on the ingredients list. So don't just rely on a lack of 'bad ingredients' on the back of the bottle. Trying it out will give you a feel for how concentrated or potent the shampoo actually is.
Sulfate-free shampoos are suited for which hair type?
Since many sulfate-free shampoos are based on gentle cleansing agents, they might not be enough to remove buildup for some people - especially people who tend to use a lot of product, or whose product options include styling butters and creams, which tend to leave difficult residues. Few sulfate-free cleansers can remove non-water soluble silicones, either.
Are sulfate-free shampoos expensive?
Sulfate-free shampoos can also work out to be expensive just for the fact that they are not as powerful. Often this means that people have to use a lot more shampoo to get the same results they would get with a sulfate shampoo.
But if you've found your ideal sulfate-free shampoo, and it takes your hair right to that equilibrium between cleansed and not stripped - it may well be worth it.
DHA Hair Care Experts
Afro Hair Show 2012
Dominican Hair Alliance
Dominican Hair Republic