At FutureDerm, I am frequently asked about the penetration and absorption of skin care ingredients.
We all know, for instance, that ingredients like Vaseline (petroleum jelly) lay atop the skin and do not penetrate the skin at all. We also know that ingredients like rubbing alcohol (isopropyl alcohol) drink completely into the skin within seconds after application.
So what gives? How do we know the other ingredients are penetrating the skin? Is this even a good thing?
Here, we will take a look at how skin care ingredient penetration works, what it means for your skin care, and how you can use this knowledge to get the most out of your products.
How Skin Care Ingredient Penetration Works
When you apply a serum, lotion, or cream, it encounters the uppermost layer of skin, which is called the stratum corneum. Depending on the size and chemical properties of the ingredients, three different things can happen:
Possibility #1: Small and Permeable: Absorbed by Skin Cells
If the ingredients in your product are small and permeable, they will be uptaken by skin cells and processed. After a period of time, the ingredients will be secreted out of the skin cells and will enter the circulation. This includes ingredients like L-ascorbic acid (vitamin C), tocopherol acetate (vitamin E), and retinol (vitamin A).
Possibility #2: Large and Non-Permeable: Goes Between Skin Cells
If the ingredients in your product are too large to be uptaken by skin cells, they will move between the skin cells for a period of time. After a while, these ingredients will also enter the circulation and be excreted from the body. These include peptide ingredients like Matrixyl 3000, which have been shown to work at a space between skin cells known as the dermo-epidermal junction (DEJ) (Cosmetics & Toiletries).[Read more: What Exactly is the 500 Daltons Rule?]
Possibility #3: Large and Non-Permeable: Is Temporarily Absorbed by Glands
If the ingredients in your product are not absorbed by your skin cells, they may also be temporarily absorbed by some glands in a process known as ”appendageal absorption”. In this process, there are “reservoir effects” in which substances may be stored within the glands for absorption over time before being released into the bloodstream. This includes ingredients like aluminum, which is the reason for some of the controversy surrounding aluminum-containing deodorants.
Is Skin Care Penetration a Good Thing?
There is a lot of controversy surrounding skin care and persons being concerned about ingredients entering their bloodstream.
On the one hand, I find this controversy to be unfounded. Consider your body for a moment to be a collection of trillions of cells, enriched by fluid. Let’s pretend the goal is to keep these cells healthy – rich in nutrients and free from toxins.[Read more: Do You Really Need a Skin Care Penetration Enhancer?]
Many of us subject our bodies to toxic substances every day. The greatest of these is not what you think; it’s actually sugar. That’s right, sugar. Like just about anything else, it can be lethal in high doses. At the time of this writing, the average American has 156 pounds of sugar per year (MedicineNet) –that’s an astonishing 770% of what is recommended for the average adult woman, a truly toxic dose. Sugar is toxic to our bodies, and yet we are literally bathing our cells in it everyday, resulting in insulin spikes and obesity, heart disease, kidney disease, and diabetes (American Journal of Clinical Nutrition).
Yet, rather than do the difficult thing and change our lifestyle, we choose instead to pinpoint our chronic health issues on a source that is out of our hands, like “big companies” and “toxic ingredients.” That leads us to controversies that are of a much, much smaller scale of importance to our health, like parabens. Truth of the matter is that natural, healthy fruits and vegetables like blueberries, carrots, and passion fruit contain parabens that are directly absorbed into the bloodstream after ingestion, sometimes at substantially higher doses than the 0.25% upper limit found in cosmetics. But I digress.[Read more: Tomatoes, Lemon, Olive Oil, and More: Are They Food, Skin Care Ingredients, or Both?]
On the other hand, as a woman who plans to have children, I understand that we all want to do the right thing for ourselves and our families. Just because we eat toxic doses of sugar doesn’t mean that we also want to be poisoning ourselves through our skin care. There have been truly astonishing skin care ingredients in years past that have made me shake my head at the industry.[Read more: Should You Be Able to Pronounce Your Skin Care Ingredients?]
Personally, I believe that the vast majority of ingredients in contemporary skin care are safe. I do not say this because I am a blogger who writes largely about skin care and cosmetics; if I thought they were not safe, I would write about something else. (For instance, I’m not a dessert blogger, because I strongly believe that too much sugar is toxic.)
I think there is more benefit to be had from improving the absorption of trace amounts of key ingredients in the skin, like vitamin C or vitamin E, than from preventing skin care or other beauty products from being absorbed into the skin. For instance, at a pH level of 3.5 or lower, vitamin C as L-ascorbic acid has been found to have greater efficacy than when at other pH levels, simply because it penetrates more deeply into the skin cells .
How to Increase the Penetration of Desired Ingredients Into Your Skin
There’s a beautiful equation for this:
This brings a tear to my nerdy eye. (If you’re not into science or math, you may just be crying. Bear with me for a moment.)
You can increase any of the above variables (except R) for greater interaction of molecules, and, ultimately, improved absorption into your skin.
- P = Increase the pressure. This is why saunas, with their high humidity levels, are so effective at getting skin care to work.
- V = Increase the volume. In this case, this essentially means you can increase the area to which the skin care product is applied. I wouldn’t gain weight just to have more skin to apply more product. Next…
- n = Increase the amount of product you apply, the frequency with which you apply it, or the concentration of active ingredients in the product.
- T = Increase the temperature. Your basal body temperature is elevated at night, so it’s a great time to apply skin care creams. Also another reason why spa owners and aestheticians love saunas so much – they help the skin cells really drink up the ingredients!
Certain ingredients (such a amino acids) naturally penetrate the skin more easily and efficiently. The amino acid tyrosine, for instance, has been proven to penetrate the skin and to enhance the penetration of other ingredients used in conjunction with it. It is available in the AminoGenesis skin care line, including the CORE4 Collection (AminoGenesis.com).
As for me, I don’t have a sauna at home or in the office, but periodically I will steam my face before applying a concentrated serum or moisturizer (increasing P, pressure, and T, temperature). I will also use concentrated serums and moisturizers, and reapply as often as my skin can tolerate — usually twice per day (increasing n). Lastly, I always make sure I have on a thick layer (n) of serum or moisturizer before bed, when my basal body temperature is the highest (T).[Read more: How Much Does pH Matter in Skin Care?]
When using body lotion, I always apply a thick layer (increasing n) to damp skin immediately after a bath or shower. I also use 100% cotton pajamas, which don’t stick to the lotion and as a result maximizes the amount applied to my skin. I also reapply before bed, when my basal body temperature is higher (T).
Skin care ingredients are either absorbed into your skin cells before passing through; pass around and then through; or are absorbed into glands before being excreted out of the body. Though there has been a lot of controversy surrounding the absorption of skin care ingredients, I think it is beneficial for your skin to increase your absorption of certain ingredients that are proven to be safe and beneficial in independent studies, like vitamin C and vitamin E. I personally recommend doing this with use of a personal steamer once or twice a week, using products with a high concentration of proven ingredients, and always applying products before bed.
What are your thoughts on this post? I’d love to know – Let me know In Comments! Let’s chat!
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