Many of us use hair care products every day, but do we know what’s truly in them? Examine the products in your bathroom, and you’ll usually find a line or two about what they specifically do not contain in their formulas. These “free from” lists tend to be universal, implying that such ingredients are probably always bad for your hair. Not so, says Prudvi Kaka, chief scientific officer of Deciem – the company behind skincare brand The Ordinary. She says: “One must take into account the concentration of use, the total formulation, the pre-existing behaviour of the hair and the specific hair concerns that need to be addressed.” In a market where brands recognise consumers want something “natural”, some companies forgo certain ingredients without investigating why they should be avoided. There are undoubtedly some ingredients that you should avoid at all costs – but are all those “bad-for-you” ingredients actually harmful, or are some of them reasonably placed in certain formulas? We take a look at some we’re told to avoid and others that are prized. Keratin Keratin is a nourishing ingredient known for being a hair superhero . Some brands have developed entire lines around it – but too much of it can harm your hair. If your hair is naturally parched or feels damaged, it may benefit from an extra shot of keratin. In some cases, though, it can cause quite the opposite effect. Keratin is a strengthener, so by using too much of it, you may be overbuilding your hair fibres’ structural integrity. When that’s done to something as thin as a hair strand, it becomes stiff and breakable, and will splinter even more quickly than if you’d left it in a debilitating condition. Sulphates Sulphates have a terrible reputation, and a lot of marketing goes into the list of negative consequences you may experience if your hair products feature them. Sulphates are a common chemical found in everyday products such as cleaners and detergents. They create a lathering, foaming effect, dissolve oils and leave surfaces feeling squeaky clean. In an interview with beauty platform Byrdie.com, Dr Orit Markowitz – a board-certified dermatologist and founder of aesthetic clinic OptiSkin – explains that sulphates’ bad reputation began in the 1990s, “when information began circulating that they can cause cancer, and the bad press continues today as more consumers lean toward natural beauty”. There’s no scientific evidence that shows the potential cancer-causing effects of sulphates in hair or skincare formulas. What sulphates can cause is dehydration and irritation, as they have the power to strip your hair of its natural oils, leaving it dry and crunchy. If you struggle with sensitive skin, they may trigger inflammation too. Ultimately, how safe sulphates are depend on how they’re formulated and on their concentration levels. “With the correct formulation techniques, cleansers containing sulphates, or any derivatives, can be created to produce a very effective product with mild, gentle cleansing,” says Kaka. As an example, The Ordinary recently launched the Sulphate 4% Cleanser for Body and Hair. The formula features a milder sulphate that, at a four per cent concentration, cleanses without irritation due to its low concentration. Parabens In simple terms, parabens are used as preservatives to stop mould and bacteria from growing in your products. They are most typically used in shampoos and conditioners. So where’s the catch? When used in high concentrations, they can play havoc with your endocrine system (which produces and releases hormones), which could lead to irritation or the worsening of skin conditions such as eczema and rosacea – some studies even suggest a link to breast cancer. Scientists have not been able to corroborate why or how parabens in beauty products could lead to such extreme outcomes, so while it can’t be said for sure that they cause cancer, it can’t be said for sure that they don’t either. Experts believe the amount of parabens in most beauty products is not a risk factor, but if you would rather be safe than sorry, there are plenty of parabens-free formulations of almost everything. Silicones The beauty industry can’t seem to decide if they love or hate silicones, which are found in almost every hair product because of their power to mitigate frizz , protect against heat and increase gloss. Silicones became a “bad” ingredient when plastic surgeons in the early ’90s claimed a link between silicone injections and breast implants and a variety of immune system diseases. Katy Freinn, a cosmetics developer and researcher at Fairleigh Dickinson University in the US state of New Jersey, explains that once an ingredient is tied to some sort of adverse side effect, “it tends to become a threat for everything, so people start wondering if it’ll be safe for them to have it be part of their products”. In the long run, experts agree there is no evidence that silicones have any health-related side effects. Superficially, though, they can build up and make your hair look dry. On top of that, silicones may leave a residue on your scalp and hair, which can weigh it down, clog your follicles – and even lead to hair loss.