"Stay away from them at all costs," a famous celebrity hairstylist once warned me, while another tutted when I told him about the great (but obviously sulphur-laden) shampoo I'd been using for years: "I mean, it's completely stripping your hair."
I was obviously washing my hair all wrong and both incidents made me completely reevaluate those quick five minutes in the shower. Buying any old shampoo on the high street would no longer cut it. Instead, I was advised to shop my shampoo in-salon or on specialist websites, paying special attention to the ingredients list on the back, because if everyone was bashing sulphates – from hairstylists to shampoo brands – they had to be really bad, right?
Not long ago, though, I ran out of the trusty sulphate-free shampoo I'd been relying on to keep my hair soft, healthy and glossy. Rifling through my bathroom cupboard for a quick substitute, I picked up any old shampoo, but as it lathered, panic set in. As I skimmed the ingredients, bubbles streaming into my eyes, the words 'sodium lauryl sulphate' jumped out at me, but it was too late. I just had to get on with it.
I had rinsed, blowdried and styled as normal when I suddenly realised that my hair had never felt cleaner. Like a second-rate shampoo-ad model, I ran my fingers through my new, super soft, lighter-than-light lengths all day and continued to use the shampoo until the very last drop. It had to be the sulphates – but how?
"Sulphates are detergents that are very beneficial in products within the hairdressing industry," says Sophie Ruggiero, Wella education expert. "They are an active ingredient, which makes shampoo foam and they really work to clean the hair's surface as well as the scalp."
"If your hair feels quite heavy then it’s important to carry out a deep cleanse," hairstylist Paul Edmonds explains further. "Sometimes hair feels cleaner and lighter if you use a product that harnesses sulphates occasionally. They work best on thicker hair types, as they allow it to become more manageable and lightweight.”
But why are we all so wary of them?
"They tend to have a bad reputation," Sophie adds, mainly for drying out hair and zapping colour. Those with sensitive or excessively dry skin may also find that sulphur increases irritation when not rinsed off properly, and in that case, investing in a sulphur-free shampoo might be a better option.
"But the amount that is used in a shampoo is actually very minimal," Sophie continues. "Most shampoos are packed with conditioning and caring agents which ensure the client gets the cleansing they require from shampoo, plus nourished hair." These substances are what Paul refers to as "buffers".
Take TRESemmé's Botanique Nourish & Replenish Shampoo, £4.99. It cleanses brilliantly from root to tip and enlists coconut oil and coconut milk to hydrate parched strands from the inside out, while Paul Mitchell's Tea Tree Special Shampoo, £16.75, gently dislodges everything from product build-up to flakes, and leaves both scalp and strands feeling fresh, not frazzled.
In short, the key to using sulphates for great hair is balance. If you're a hair product junkie (guilty) and love to slather on serums, oils and styling cremes, then washing your hair with them twice a month works a treat to remove build-up, not to mention dead skin cells, oil and grime. "Deep-cleansing the hair a couple of times a month is ample, depending on your hair type," seconds Paul. Those with finer hair might not want to use them as often.
So when should you definitely not?
"Regular use of sulphates don't work well with keratin treatments as they contribute to the breaking down of the chemicals within said treatment," explains Mark Woolley, celebrity hairdresser and founder of Electric Hairdressing. "In short, this can undo the effects of the treatment, so I would always recommend following any services with the recommended aftercare routine – you can still remove just as much dirt and excess oil from the hair with a sulphate-free shampoo. Overall, though, I’d say that sulphates are safe to use and they can provide good results, but over time can be damaging to treated hair," Mark adds.
But believe it or not, the same might not apply to coloured hair.
"There is a lack of scientific proof that sulphates are bad for coloured hair," says Sophie. "The key to prolonging colour and reducing colour fade is using products that are designed to lock the colour in, give protection (including products that block UV), and add both moisture and protein to keep it in tip top condition. The better your hair condition, the better your colour will be."
Not too scary now, are they?