There are a high proportion of men who are concerned about the potential for male hair loss and if they start to notice more strands falling out of their head than usual or a noticeable clump, they start to look at potential causes, and one that commonly gets blamed is shampoo.
The reason is often mere correlation; because you often touch your hair the most when washing it, you naturally notice more of the 50 to 100 hairs most people lose a day as part of our natural hair cycle and because the shampoo bottle is the closest potential culprit can start pointing the figure.
However, is there any truth to the idea that shampooing or conditioning your hair frequently can contribute to hair loss? Not necessarily.
Just washing your hair will dislodge hair strands that have already come loose, as will combing, brushing your hair or tussling it, but these actions on their own did not cause your hair loss, which can be the result of a variety of different causes from genetics to stress.
However, with that said, there are a lot of ingredients in most of the shampoos we can buy, and some of them can potentially cause hair loss, although currently there is very little research that confirms this to be the case at the levels you are likely to experience them in the shower.
Sulphate cleansing agents such as sodium lauryl sulphate, are irritants that can upset our skin and cause redness at high doses. At the same time, this can also cause irritation to the hair follicles, which can result in broken strands, which sometimes merely resembles hair loss and sometimes can be its cause.
As well as this, the formaldehyde preservative often used in many products at low levels has been connected to hair loss but is found at such low doses in shampoo that it only affects people who work regularly in salons and hairdressers.
Ultimately there is very little evidence to suggest that either affects hair loss outside of anecdotes, although for other reasons it can be worth avoiding them.