|MadSci Network: General Biology|
Hi Sharon, The simple answer to your question is YES – different lotions leave different amounts of moisture trapped in the skin. A fuller explanation needs a bit of science and some big words so get ready! There are several types of moisturising chemical and they work in different ways. Some form a waterproof layer on top of the skin to trap the water already there, these are called emollients ( pronounced ee-mole-ee-ents ). Others try to get the skin to exfoliate ( pronounced ex-fole-ee-ate ) – that is, to shed the top layer of skin which is dry and replace it with a younger layer of skin which still contains moisture. The most common examples of these are the Alpha Hydroxy Acids ( AHAs ) and the Beta Hydroxy Acids ( BHAs ). Hydroxy is pronounced hi-drox-ee. Other moisturisers use little chemical ‘baggies’ called liposomes ( pronounced lie-po-sew-ms ) to carry water deep into the skin. Most moisturising lotions use a combination of the different types of chemical such as liposomes to carry water into the skin and an emolliant to stop it from evaporating. The Alpha and Beta Hydroxy Acids come in several strengths – you can buy lotions with 2 – 8% Hydroxy Acid over the counter. Stronger lotions with 12 – 15% Hydroxy Acid have to be prescribed by a doctor. The stronger lotions have been shown to be better at improving the condition of the skin. Different lotions will contain different moisturising chemicals at different strengths, so each lotion will trap different amounts of moisture within the skin. Here are some web sites with some more information. Most of these sites have a ‘CONTACT US’ or ‘E-MAIL US’ banner so you might ask the companies for information about their products. If some of the names are unfamiliar it is because I’m from England and the products may have different names in England and the USA. Dove can be found at http://www.dovespa.com/generic/articles/alpha.html Nivea can be found at http://www.nivea.com/cfdocs/nivea/top.cfm Oil of Olay can be found at http://www.olay.com/homebody.htm Information about the different types of moisturisers can be found at – http://www.biol.napier.ac.uk/bws/courses/projects/eczema/eczema/otem.htm This is a page about emollients. http://www.dermcon.com/ahafacts.htm This is a page about AHAs. http://beauty.about.com/msub9.htm This site contains links to other sites with information about AHAs, BHAs, exfoliants and a site called Ask Dr.Weil. Last but not least is a site which contains recipes for all kinds of cosmetics including moisturisers called Rachel’s Supply which can be found at http://www.seedman.com/Rachel/recipe/recipe.htm Hope this is of help. NIGE
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