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Medical Is leaving the shampoo in your hair for a long time dangerous

  1. Aug 21, 2010 #1
    Is leaving the shampoo in your hair for a long time dangerous? Wouldn't that give the scalp more time to absorb the active chemicals in the shampoo? And is it really impostant to rinse off your shampooed head thoroughly to wash away all the shampoo?

    Is using a separate conditioner better than shampoo plus conditioner mix?

    Please help me with the above queries. Thanks.
  2. jcsd
  3. Aug 21, 2010 #2


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    What do you mean by "a long time"?
  4. Aug 21, 2010 #3
    Meant was a longer period of time than specified, say half an hour instead of three minutes.
  5. Aug 21, 2010 #4


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    Most shampoos contain sodium lauryl sulfate, which can be a skin irritant. It is a major component in engine de-greasers, car wash detergents, etc, because it is so good at removing oils and greases. I'd say that it is prudent to lather up once and rinse thoroughly to avoid drying out your scalp and hair.

    If I had hair that was so dry the a conditioner was required, I would certainly find a separate conditioner so that it could be applied *after* the shampoo was thoroughly rinsed out.
  6. Aug 21, 2010 #5


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    The main ingredient in most shampoos is ammonium lauryl sulfate. It is an irritant but that http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2230.1988.tb00641.x/abstract" [Broken]. The other components in the formulation can also cause or ameliorate irritation.

    If the shampoo is medicated, other stuff might happen but I don't think 30 minutes would cause any serious injury. Shampoos are usually formulated to be very gentle so they don't burn your eyes.
    Last edited by a moderator: May 4, 2017
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