This morning I was asked about Dimethicone and does it “Suffocate” the skin and trap bacteria? Also does it prevent the skin from sweating and hinder exfoliation?
The question comes because their clients found this site. The author states first of all that it is safe and that it has skin benefits especially for atopic dermatitis but then goes on to say in her opinion that she doesn’t think it is a good ingredient.
My first comment is what qualifications does she have? When you read something on the internet or your clients do they should be questioning is this a person of authority and do they really know what they are talking about? Also the article is not referenced properly either and the author does not cite where they got their information from. The article does not cite any references pertaining to the information as it is written. All they provide is a general reference list down the bottom, which does not help you validate the information.
In the article below are the listed reasons of why apparently Dimethicone is bad for your skin……We will address these in detail. My comments and responses to each of these allegations is in burgundy.
Why Dimethicone is Bad for Your Skin
That artificial coating on the outside of skin causes several issues:
1. It traps everything under it—including bacteria, sebum, and impurities—which could lead to increased breakouts and blackheads.
Dimethicone has been shown time and time again to be non-comedogenic. “Dimethicone is the ideal skin barrier enhancer because it is hypoallergenic, noncomedogenic, and nonacnegenic.”  It is also widely used in acne preparations for this exact reason. It actually helps acne lesions by facilitate healing and preventing scarring. So to state that it causes acne is false. Most often those who allege it causes breakouts are actually breaking out from something else in the formula, as it is not the Dimethicone.
As far as trapping everything again this is FALSE. Silicones and Dimethicone form a “vapour permeable” barrier. Now this is important. Despite MANY not realising this, yes our skin does breathe and yes it exchanges oxygen. The reason it is important because anything that is totally occlusive does damage the skin. Do not confuse the ability of it to slow down moisture loss as occlusion. What Dimethicone does is prevent moisture loss but allows the skin to breathe.
It functions as a non-greasy occlusive agent, putting a thin water-impermeable (not gas impermeable) film over damaged skin that exhibits increased transepidermal water loss. The film maximizes the environment for barrier repair, which is necessary for the healing of xerotic and dermatitis skin conditions. It also creates an artificial barrier until the skin can repair itself. Lastly, it increases skin smoothness by functioning as an emollient to fill in gaps where damaged corneocytes are missing from the stratum corneum.
2. The coating action actually prevents the skin from performing its normal activities—like sweating, temperature regulating, sloughing off dead skin cells, etc.
No proof of how they came to this conclusion is even out there.
3. Prolonged exposure to dimethicone can actually increase skin irritation, due to the coating property and because dimethicone is listed as a possible skin and eye irritant
This is another case of someone grabbing a MSDS and inferring that use in an industrial setting or 100% use can be inferred by cosmetic use. This is not correct. Again the opposite is true. Sunscreens are often coated with Dimethicone to prevent irritation to the skin. Those with Rosacea often have issues with sunscreens. The coating of the particles of Zinc Oxide and Titanium Dioxide reduce this potential for irritation and it is recommended for Rosacea for this reason. 
4. Those with sensitive or reactive skin are at risk of an allergic reaction to dimethicone
Again the opposite is true. It is actually one of the safest things to use on an allergic skin. It doesn’t sting and helps to heal the skin by forming an artificial vapour permeable barrier. It is the reason it is used for Atopic Dermatitis and Eczema.
5. I also believe that using these types of ingredients on your skin can actually exacerbate skin aging. Why? You’re inhibiting skin’s natural processes
No they don’t! They help heal the skin quicker. Studies have shown that silicones do NOT interfere with the skins ability to repair the skin barrier when used. They do not interact with the stratum corneum  The study investigated the use of four silicones (Dimethicone) and its interaction with the stratum corneum.
The results revealed that the investigated Silicones do not change either the micro-structure or the biphasic lamellar/inverse hexagonal structure of the skin. We concluded that Silicones will not cause any side-effects when topically applied. One of the reasons Albert Kligman endorsed silicones for use in repairing the skin barrier.
6. You’re creating a dependency on the coating product, disrupting the skin’s own hydrating processes, which in the end increases dryness, making fine lines and wrinkles more noticeable.
Short et al. showed that a moisturizer containing high amounts of glycerin and silicones increased maximum epidermal thickness, decreased epidermal melanin content, and altered protein expressions of keratins 6, 10, and 16, as assessed with immunohistochemistry after a 4-week treatment. Moreover, all these changes were accompanied by decreased TEWL. 
7. The coating properties may increase breakouts, particularly if you’re susceptible to acne, which will lead to scars and older-looking skin
Actually it decreases the risk of scars. Silicones increase the amount of TGFB-3. For those of you with knowledge you will realise that TGFB-3 occurs when there is scarless healing. So it is of so much benefit for acne skins.
Apart from improving the feel and long-lasting benefits of skin care products, silicones can also enhance the efficacy of other ingredients in the formulation. Studies carried out on sun care products have shown that the alkyl methicones can enhance the SPF of products containing either organic or inorganic sunscreens. A 2% addition level of stearyl dimethicone into an oil-in-water silicone containing 11% of organic sunscreens resulted in an in vivo SPF of 49.7, an SPF/UVB ratio of 4.5, thus demonstrating high efficiency . For inorganic sunscreens, a 100% increase in SPF was seen with an oil-in-water system containing 2 wt% cetyl dimethicone and a 75% increase in the SPF for a water-in-oil system containing C30-45 alkyl methicone 
There is so much misinformation spread in this industry and on the internet. We need to be vigilant about ensuring our education is up to date to position yourself as an expert. Consumers are getting more savvy and researching about the ingredients in their products, unfortunately there are many so called experts who cite wrong information. Also the question of their agenda needs to be considered as well. Anybody who is stating there is something wrong with an ingredient and then tries to sell you their own product has an agenda.
About the Author
Jacine Greenwood is an internationally recognised educator who is known within the industry for her up to date knowledge and her ability to deliver training in an easy to understand method.
Jacine holds 6 Diplomas and a Bachelor of Nursing and her knowledge is well respected by her peers. She is also a qualified Cosmetic Chemist. With over 19 years experience in the industry and a background of cosmetic formulation, Jacine has an immense knowledge of current trends in research and new developments in the industry.
Jacine has been continually educating herself in all aspects of skin function and cosmetic chemistry for the past 21 years. Jacine’s knowledge is current and has a vast knowledge of the active ingredients that are being released onto the market.
Draelos ZD1, Callender V, Young C, Dhawan SS.Cutis. The effect of vehicle formulation on acne medication tolerability. 2008 Oct;82(4):281-4.
Glombitza B, Muller-Goymann CC (2001) Investigation of interactions between silicones and stratum corneum lipids. Int J Cosmet Sci 23:25–34
Nichols K, Desai N, Lebwohl M. Effective sunscreen ingredients and cutaneous irritation in patients with rosacea. Cutis 1998; 61:344–346.
P. M. Elias, “Epilogue: fixing the barrier—theory and rational deployment,” in Skin Barrier, P. M. Elias and K. R. Feingold, Eds., pp. 591–600, Taylor & Francis, New York, NY, USA, 2006.
Short RW, Chan JL, Choi JM, Egbert BM, Rehmus WE, Kimball AB (2007) Effects of moisturization on epidermal homeostasis and differentiation. Clin Exp Dermatol 32(1):88–90, Epub 2006 Nov 27
Glombitza B and MuÈller-Goymann C. Investigation of interactions between silicones and stratum corneum lipids. International Journal of Cosmetic Science, 2001, 23, 25-34
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