You may have seen the BBC2 programme 'Trust me, I'm a doctor' broadcast on 22 July in which the value of skin and hair cleansing and the safety of one of the widely used cosmetic ingredients was questioned. The presenter also questioned the value of applying a moisturiser to the skin. In case you are concerned about what the programme was saying, we'd like to put the record straight.
The ingredient, sodium lauryl sulphate or SLS, is widely used in shampoos, hand and body washes because it is safe and effective for cleaning the skin and hair. We know that at high concentrations or if left in contact with the skin, it will cause irritation. The presenter demonstrated this when he left SLS on his skin for three weeks. But that is not how we use shampoos, hand and body washes. We rinse them off in order to clean the skin and hair and common experience shows this does not cause a problem for the overwhelming majority of people.
Moisturising the skin is a valuable aid to keeping the skin in good condition and avoiding dryness, roughness and a feeling of tightness. Most people know that from practical experience. Although the measurements taken by the presenter showed no difference in the rate at which moisturised and untreated skin lost water, that measure alone cannot show the softness, lack of dryness and improved suppleness that moisturisers impart to the skin and which users know about from their daily experience.
Some moisturisers do contain SLS but the levels are far lower than are used in shampoos and cleansers and are there simply to ensure the cream or lotion does not split (break down). At these low levels, SLS does not irritate the skin even when left in contact. If this were the case, it would simply not be used.
People who suffer from eczema and other skin conditions know they have to be careful about what they apply to their skin and we agree with Professor Richard Guy when he says if you have such a condition you may be better to avoid SLS, but he also clearly said SLS was not a problem for normal skin.