Are sulfates good or bad? What do they do to natural hair? Does sulphate-free shampoo make hair greasy?
Sulfates are the most controversial ingredients in haircare, but most of us don't know why we hate them so much.
Think you know all there is to know about these ingredients? Well here's the whole truth about sulfates.
Why sulfates became one of the most hated ingredients
Once upon a time, almost everyone washed their hair with shampoos powered by small, but potent cleansers. These frothy soap replacements were easy to rinse from the hair, produced tons of lather and left hair squeaky clean. They were nicknamed "sulfates" by formulators, but pretty much no one else had ever heard of them.
Sulfates are often blamed for dryness in curly hair. Image by the Collab.
Until 2001, the year sulfates were officially designated Public Enemy No. 1. The alarm was raised by an influential curly hairstylist who had just dropped her first book. In it, she blamed sulfates for the frizz and dryness that many people with curly hair struggle with. And little by little, natural hair sites and beauty magazines started turning on the ingredients they had been using for years.
By the 2010s, strange words like "no poo", "co-wash" and "CG-friendly" had crossed into mainstream beauty speak. Soon nearly everyone was asking, "Is that sulfate-free?" at the hair shop - whether they knew what sulfates were or not.
So what is sulfate?
First off, 'sulfate' isn't a single ingredient. When an ingredient has sulfate in its name, it means part of that molecule contains a little group composed of a sulphur atom joined to 4 oxygen atoms. Lots and lots of very different ingredients have sulfate groups - everything from natural minerals used to make plaster, to dyes, to magnesium sulphate aka Epsom salts - which by the way, can be very good for your scalp.
On natural hair, sodium laureth sulfate is a more moderate sulfate cleanser. Image by Edgar181.
But the sulfates people are usually talking about when it comes to hair are the kind that clean your hair; the anionic surfactants. These ingredients are molecules with a water-loving head and an oil-loving tail. Their superpower is that they can make two ingredients that usually hate each other - water and oil - join together. Sulfates use this superpower to work as cleansers, the most popular type in shampoos.
Is sulfate bad for hair?
Not all 'sulfate' ingredients have any effect on your hair at all. Sodium sulfate is used in cosmetics to thicken the product itself, without actually acting on your strands. Others, like magnesium sulfate, are rarely included in haircare, but tend to show up in products with an emphasis on scalp care.
So even if you're going 'sulfate free', don't panic if you see the word sulfate on an ingredients list right after 'sodium' or 'magnesium'. It's not what people are talking about when they say 'sulfate shampoo'.
What they are talking about are these ingredients:
sodium lauryl sulfate
sodium laureth sulfate
ammonium lauryl sulfate
ammonium laureth sulfate
These are the main four cleansing agents, called sulfates for short, which have become so controversial in recent years. So are they bad? Some sulfates are good to your hair, some are somewhere in the middle, and some can be pretty bad for hair. How can you tell them apart? We'll get to that in a minute.
What does sulfate do to natural hair?
The main thing sulfates do to natural hair is cleanse it. The problem is, sometimes, they do this job a little too well. When sulfate concentration is too high in a shampoo formula, it can remove more from your hair than just the dirt, product buildup and grease you want it to remove.
At high concentrations, sulfates can strip your hair of its bound lipids - oils that are naturally stuck to your cuticle, and whose job is to sit tight on the surface and protect it. Over time, this leaves your hair dried out, brittle, frizzy and rough.
Scarily, the most overzealous sulphates actually create little holes in your strands, as they go deep to remove oil, leaving hair weaker and more porous. The sulphates that do this are the smaller, harsher sulfates, the ones with lauryl in their name - like sodium lauryl sulfate and ammonium lauryl sulfate.
Avoid using sodium lauryl sulfate on your natural hair. Image by Lucas Lenzi.
But not all sulfates do this. Laureth sulfates are chemically modified to be milder. The same goes for the lesser known myreth sulfates which are also bigger, way too large to penetrate the strand, and so way gentler, too.
If you're planning on using a sulphate shampoo, formulas that say sodium laureth sulfate, sodium myreth sulfate or ammonium laureth sulfate on the label should be able to cleanse your hair without completely stripping it.
What's the difference between sulfates and sulphates?
Nothing! Chemically, they're exactly the same. Sulphate is simply the 'British' (Or Jamaican or Canadian or Australian...) spelling, while sulfate is the way it's spelled in the US. We've used both interchangeably in this article.
What's the best sulfate shampoo for natural hair?
The best sulfate shampoo for natural hair will contain a laureth sulfate or myreth sulphate, whether that's sodium laureth sulfate, sodium myreth sulfate or ammonium laureth sulfate.
The best sulfate shampoos contain laureth or myreth sulfate, as used in La Aplanadora Shampoo.
Avoid lauryl sulphates if you don't want to overcleanse or create minute cracks in your cuticle surface. While you might be able to get away with using them occasionally in a well-formulated shampoo, they shouldn't be part of your regular natural hair regimen unless you have seriously robust hair.
A good sulfate shampoo won't be too concentrated, either. If it's well-formulated, the shampoo should be strong enough to remove stubborn residue, including product buildup, grease and pollution - but balanced, to avoid being too harsh on your hair.
One more thing; the ideal sulfate shampoo will also cleanse without leaving buildup. On low porosity hair in particular, which has the lowest tolerance for residue, it's best to avoid any shampoo that dumps a ton of unnecessary ingredients on your hair that you can't rinse away.
A residue-free cleanser will allow your conditioner the space it needs to work to maximum effect, instead of having to compete with bits of leftover shampoo. And most importantly, it means your scalp can breathe!
Shampoos we've tested that fit the ideal sulfate shampoo criteria include atrActiva AntiStress Shampoo, which recently won the Award For Best Clarifying Shampoo, and Capilo La Aplanadora Shampoo.
Both of these are deep cleansers, meaning they're suited for use as clarifying shampoos to remove weeks of buildup, or as a once weekly cleanser if you use a fair amount of product. A moderate cleanser for more frequent use is Silicon Mix Shampoo, which you can use multiple times a week without overcleansing.
Does sulfate-free shampoo makes hair greasy?
Since the backlash against sulfates began, sulfate-free formulas have become more popular. Unfortunately, some sulfate-free shampoos do leave hair feeling greasy. Sometimes, it's because they're based on milder cleansing agents which can struggle to remove greasy buildup already on the hair.
And because these cleansing agents are so mild, they might have to be used at a higher concentration, which can be drying to the hair and scalp - causing your scalp to overcompensate by producing more oil.
Sulfate-free shampoos can leave hair greasy as they contain weaker cleansers. Image by Barbara Asboth.
The last reason why sulfate-free cleansers can leave your hair greasy might be disturbing for anyone avoiding sulfates because of their rep as harsh cleansers: Some sulfate-free shampoos contain cleansing agents that are actually harsher than most sulfates.
To mask their effect, manufacturers often include a lot of conditioning ingredients in the formula so you can't actually feel that your hair is drying out. These ingredients can build up on your hair, leaving it feeling greasy instead.
That said, there are sulfate-free shampoos, for example, Halka Baba de Caracol Sulfate Free Shampoo, which don't do any of the above. Good sulfate-free shampoos will clean hair well without overloading it with grease or overcleansing it, but in practice, it's very tricky for formulators to get the balance right, which is why it's so hard to find a good sulfate-free shampoo.
Are sulfates safe for your health?
There are studies out there which link sulfates to skin cell damage. However, these tend to be based on sulfates used at higher concentrations, and leaving the ingredient on your skin, which you wouldn't ordinarily do with shampoo.
The safety of every ingredient is "dose-dependent" and even sulfate-free cleansers and conditioning agents have maximum levels above which they should not be used in products for safety reasons.
Finally, like any other ingredient, some people can be allergic to sulfates. If you are, definitely don't use them.
Are there naturals who use sulfate shampoo?
Despite the widespread fear of sulfates in the natural community, there are tons of naturals who use sulfate shampoo. Some of them are recent re-converts to sulfate shampoos, like Jonell Sequira, others, like NappyFu - who has a really informative video on the topic - never left.
There are a couple of major reasons why they do. Since people with natural hair tend to use a lot more styling butters, oils and custard or pudding-type stylers, they tend to need better buildup removal than people with other hair types. The ingredients in these products can be hard to remove with co-washes, hair teas, or sulfate-free shampoos.
The rich butters used by many naturals can be hard to remove with co-washes, clays and sulfate-free shampoos. Image by Crishna Simmons.
Can you use sulfates on low porosity hair?
You can definitely use sulphate shampoos on low porosity hair. Sulphates are great at removing the type of debris that other cleansers leave behind. They'll pick up a lot of the product residue these alternatives miss, as well as more of the usual stuff like dirt, sweat, sebum and pollutants.
When you have natural low porosity hair - especially 4C hair, which tends to have super low porosity - this level of effective cleansing has especially high value.
Why? The surface of low porosity hair is less absorbent and more prone to buildup, so shampoos that don't effectively remove surface residue can actually block the effects of conditioners, interfere with styling, and affect the way hair feels. Since they're so good at this step, sulfates can eliminate this problem, making low porosity hair easier to condition, moisturise and handle.
Sulfates: One thing you should never do
Warning: sulfates are potent cleansers. Skipping conditioner afterwards, even if the sulfate shampoo you used says "2-in-1" or "moisturising" on the label, is a no-no. Following sulfate shampoos up with a good conditioner is a must if you don't want your hair to dry out.
And since they clean the surface so well, treatments - especially moisture treatments - usually work better after using a sulfate shampoo than other cleansers, so there's no excuse to skip conditioner, ever.