ARE 2-IN-1 SHAMPOOS A GOOD IDEA? I was asked by a beauty journalist this morning if I thought 2-in-1 Shampoos are a good idea? If anyone is interested this… was my answer: I would not recommend anyone use 2-in-1 shampoos because they are not nearly as effective at improving the condition of your hair as a separate shampoo and conditioner.
Let me explain why. A 2-in-1 shampoo is a shampoo – not a conditioner. It is a shampoo with some conditioning agents added (which a good shampoo should have anyway), but in a 2-in-1 they are used at a higher level and may be of a different kind. For example, a silicone called Dimethicone is commonly used in 2-in-1 shampoos because it adheres to the hair putting a coating on it which improves the hair’s feel and gives it a degree of protection, but it is poor at increasing the moisture content of the hair and improving the structure, elasticity and tensile strength of the hair which is what you should expect from a good quality, separate conditioner.
Warning – the science bit!
Using a separate shampoo and conditioner is very much better for the hair because a typical shampoo has a negative electrical charge (anionic). Because the electrical charge of hair is either neutral or also negative it means there is no natural attraction between a shampoo and the hair, so the shampoo goes onto the hair mixes with the oils and dirt and is easily rinsed away. In contrast to this a conditioner has a positive electrical charge (cationic) meaning that there is a natural attraction between it and the hair, so the conditioner is attracted to the hair and a certain quantity of it adheres to the hair after the bulk is rinsed off.
The important differences between this action and those of a silicone coating are that the conditioner can penetrate into the hair and, very importantly, have positive effects in the cortex (the internal fibres of the hair), whereas silicones are simply dumped on the surface of the hair. In fact so much silicone can be deposited on the hair it can feel more like a nylon wig than human hair. This is because as hairs pass over neighboring hairs what you feel is actually silicone ‘gliding’ over silicone, rather than hair-over-hair. A conditioner on the other hand, only adheres to the hair where it is needed. This is because as the hair becomes drier and damaged its negative electrical charge increases, so where hair is in good condition it has no, or very little, electrical charge so the conditioner (with a positive charge) is not attracted to it. But where the hair is dry and damaged its negative electrical charge is strong so the positively charged conditioner is attracted to those regions, and thus has a conditioning effect where it’s most needed.
Hairdressers Finally, some hairdressers complain that colours or other chemical processes sometimes don’t take properly when a 2-in-1 shampoo has been used prior to the client visiting the salon. This can be because the silicone is creating such an effective waterproof barrier that water based materials used in chemical processing simply cannot penetrate the outer region of the hair (the cuticle) to reach the internal fibres (the cortex) where permanent colour changes take place. So for the sake of your hair – and your hairdresser’s sanity – don’t use a 2-in-1 shampoo prior to a visit to the salon, or better still, not at all.