Skin health
Why Your Research into Skincare Products Should Be More Than Skin-Deep
Estimated reading time: 8 minutes
Podcast version
An expectation for instant results with minimal effort has permeated almost every aspect of life, including the look of our skin.
Our largest organ acts as a natural barrier that protects us from toxins, harmful bacteria and even the cold. Yet many people appear willing to risk harming it to enhance their appearance, sometimes by using cheaper, potentially dangerous DIY treatments.
So, how can we benefit from skincare products safely without compromising the achievement of meaningful results?, what are the best ways to get plant-derived, effective ingredients into the skin itself, and what’s the best way to layer products? Read on to find out.
Skin Absorption vs Skin Penetration: What’s the Difference?
To understand the nuances of these 2 similar-sounding terms, it helps to picture a cross-section of the skin and its 3 layers.
On top, you’ll find the waterproof barrier, known as the epidermis. The stratum corneum is its outermost covering. It consists of layers of dead skin cells overlapping like tiles on a roof and glued together mainly by fatty acids.
The dermis is the central layer of the skin. Collagen, elastin, connective tissue, hair follicles, blood vessels and sweat glands all reside here.
The bottom layer of the skin is the hypodermis, made up of fat and connective tissue.
In cosmetics, skin absorption is a term used when something, typically a targeted chemical, makes its way into and between the skin’s cells and remains there. It can also refer to a chemical getting as far as the bloodstream from the skin’s surface.
Skin penetration refers to the depth of the journey an ingredient makes through the stratum corneum and into the lower layers of the skin.
You might see skin absorption as being “skin penetration plus” or “skin penetration with purpose.”
Perhaps confusingly, recently there’s been more online chatter than usual about links between skin absorption and the bloodstream. This has largely been down to unfounded scare stories which we’ll discuss later.
How Ingredients Get Into the Skin
There are 3 potential pathways for the epidermal penetration of active compounds.
The first is penetration through the sebaceous and/or sweat glands and the hair follicle.
The accepted view is that because hair follicles and glands make up such a small proportion of the skin’s total area for permeation, their significance in epidermal permeation is typically small.
Intercellular penetration allows ingredients to get through the “glue” between the cells of the stratum corneum.
Intracellular permeation takes place through the functionally dead, dense cells of the outer layer of skin, the Stratum Corneum. Only very small molecules can absorb into the skin in this way.
How Easy Is It for Ingredients to Penetrate or Get Absorbed?
The simple answer is, “probably a little harder than you’d think,” perhaps not so much of a surprise given that one of the functions of the skin is as a protector. There are some determining factors that are always at play.
Some parts of the body such as the face, particularly around the eyes, have thinner layers of skin than others, theoretically making absorption and penetration easier. The condition of the skin matters too. One reason to exfoliate is to manually get rid of dead skin in an effort to help speed up the journey of ingredients deeper into its layers.
The molecular structure of an ingredient matters as well. The barrier function of skin, mainly attributed to the stratum corneum, only allows small molecules to pass through. There are some ingredients that have molecules which, although too big to penetrate the skin, may still perform a useful skincare function on the skin’s surface.
Oil-soluble ingredients, can pass through the lipid-rich intercellular spaces in the stratum corneum more easily, allowing them to penetrate deeper into the epidermis and, in some cases, even reach the dermis.
On the other hand, water-soluble ingredients face more challenges when it comes to penetrating the skin barrier. However, certain smaller water-soluble molecules, such as hyaluronic acid or some peptides, can penetrate to a limited extent due to their unique properties and interactions with the skin. We use hyaluronic acid in our Fruits & Seeds Eye Cream and our Hemp & Algae Face Cream.
Skincare Products Get Absorbed Into the Bloodstream: True or False?
The journey through the skin’s layers and into the bloodstream for a humble molecule would turn the stomach of the most seasoned adventurer.
The process is not as simple as, say, putting something with a tiny molecular structure on your skin and waiting for it to penetrate through to the bloodstream. It takes years of testing and research to develop transdermal products.
Even the skin’s outer layer can have 15 or so layers of cells to bypass or cut through. It would take unbelievably large doses and months and months of constant application for many of the strongest ingredients to enter the bloodstream through the skin.
So, while some kinds of skincare products might get into the bloodstream, it’s nigh on impossible for most to.
The way chemicals react in the body depends not just on the chemical itself. Our sex, diet, age, genetic background, previous exposures, and diet all affect the way the body manages chemicals and their potential effects, adverse or otherwise.
“Experts Have a Skinful of the 60 per cent Myth”
There’s a now-famous tale perpetuated online that suggests 60 per cent of what we apply on the skin will get into the bloodstream. It’s reassuring that internet search results display a mass of biologists and chemists willing to dismiss the claim due to a total lack of evidence.
If the process were that easy, scientists wouldn’t have spent years developing patches to deliver compounds like nicotine or hormones like oestrogen into the bloodstream. Formulated in a different way to skincare cosmetics, the patches allow for the slow release of specific chemicals over relatively long periods of time.
The Risk of Chemicals in Sunscreen Products
Within the last few years, the U.S. Food and Drug Administration (FDA), carried out several studies that found traces of sunscreen skincare chemicals in the blood of participants – the US government considers sunscreens over-the-counter medications, whereas in the UK/EU they are classified as personal care products or cosmetics.
The studies concluded that absorption does not equal risk. The bottom line is that we simply do not know enough yet about any potential long-term effects and further research is ongoing to better understand the potential implications of long-term exposure and cumulative effects.
Ingredients such as zinc oxide and titanium dioxide, have minimal systemic absorption. They sit on the surface of the skin and deflect UV rays. This type of sunscreen, also called physical sunscreen.
We’ve dedicated an entire blog post to sunscreens and you can find it here.
Which Ingredients Help in the Absorption and Penetration Processes?
You’ll often see water as the primary INCI (International Nomenclature Cosmetic Ingredient) listed on a product’s ingredients. INCI is the systematic name used internationally to identify cosmetic ingredients. These ingredients then get listed on packaging in descending order of weight.
Water can act as the key soluble carrier to get ingredients into the skin. When combined with other substances it has a better chance of penetrating further. For example, mixing water with oil using an emulsifier has long been one of the most common ways to improve skin penetration.
There are, however, many enhancers known to facilitate skin penetration. These include: alcohols, surfactants (used in cleansers), organogels, emulsion and microemulsions, gels and liposomes.
Liposomes are tiny spherical structures or vesicles made up of lipids, which are similar to the natural fats found in our skin and contain inside a specific active ingredient. When applied to the skin, the liposomal structure helps to protect the active ingredient and facilitate its absorption into the deeper layers of the skin. The liposomes can fuse with the skin’s cell membranes, allowing the ingredient inside the liposome to be released and taken up by the skin cells. We use liposomal hemp extract in our Hemp & Algae Face Cream.
In the UK and EU, certain groups of substances, such as colourants, preservatives and UV filters, including those that are nanomaterials, require authorisation before use in cosmetic products. The perceived danger is that they may get absorbed into the bloodstream more easily.
There are plenty of plant-derived versions of enhancers that both penetrate the skin more efficiently and have beneficial skincare properties too. You’ll find these in plants, nuts, sugars, berries and leaves. Here are some examples we use:
Glycerin is a humectant that draws water to the skin. It has excellent emollient and water-retaining properties. It boosts skin elasticity too and it has bee found to have some mild penetration-enhancing properties. The one we use is palm-free.
Licorice extract (Glycyrrhiza glabra): Licorice extract contains active components like glycyrrhizin and glabridin, which have demonstrated penetration-enhancing effects. They can facilitate the delivery of other active ingredients into the skin.
Rosemary Leaf Extract: Rosemary extract has been investigated for its ability to enhance the penetration of various active compounds. It contains components like rosmarinic acid and carnosic acid, which exhibit penetration-enhancing properties.
Quillaja Saponaria (Soapbark) Wood Extract: Contains natural surfactants called saponins. Saponins have the ability to disrupt the stratum corneum, the outermost layer of the skin, and increase its permeability. This disruption allows for improved absorption of other active ingredients that are present in the formulation.
The Best Way to Layer Facial Skincare Products
If you use several facial skincare products, you are likely to find that they penetrate better if you use them in the right order. Less is more, so if you find you’re using more than a handful of products on each occasion, then you should take a step back and reassess.
An exfoliant once or twice a week is going to help get rid of dead skin on the epidermis and that is going to help enhance penetration into the skin.
On a daily basis, after using a mild cleanser morning and evening, a general rule of thumb is then to go by the order of your products’ consistencies, using the thinnest, most lightweight first.
This is where the first ingredient of an INCI list is helpful. Given that the list starts with the one that takes up the most weight, you’ll know that if water is the predominant ingredient it would be a good choice of skincare product to use first. You would then follow that up with serums and then more oil-rich products.
Waterless products, such as our Triple Algae Glow Restoring Oil, are designed to create a protective layer on the skin’s surface. They can help to seal in moisture and prevent water loss from the skin. If applied before water-containing products, they create a barrier that can impede the absorption and effectiveness of the water-containing products.
By applying water-containing products first, you allow them to penetrate and nourish the skin, and then follow up with waterless products to lock in the moisture and provide additional protection. This layering technique allows for optimal absorption and benefits from both types of products.
It’s important to point out that our Papaya & Bakuchiol Gel Serum has a very low water content so should be applied after any water-based serums or creams – so after our Fruits & Seeds Eye Cream and our Hemp & Algae Face Cream if you use them too. Remember to gently massage each product until fully absorbed before moving to the next step.
Always Check the Ingredients of Your Skincare Products
We’ve gone to great lengths to choose all our ingredients and to explain their origin and benefits for the skin.
On each product page, you’ll find a short explanation by clicking on each ingredient without you even having to leave the page itself.
You can also find a dedicated page on our website with all our ingredients. Try it out and discover more about the properties of the botanical ingredients we use in our vegan skincare range.
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Sources and further reading:
https://www.bbc.co.uk/news/uk-65273991
https://biomeddermatol.biomedcentral.com/articles/10.1186/s41702-020-0058-7
https://www.sciencedirect.com/science/article/pii/S1226845316301282
https://www.bbc.com/future/article/20220512-the-chemicals-that-linger-for-decades-in-your-blood
https://www.fda.gov/news-events/fda-voices/shedding-more-light-sunscreen-absorption
https://www.betterhealth.vic.gov.au/health/healthyliving/How-drugs-affect-your-body
https://www.gov.uk/guidance/making-cosmetic-products-available-to-consumers-in-great-britain
Rawlings, A. V., & Lombard, K. J. (2012). A review on the extensive skin benefits of glycerine. Journal of the European Academy of Dermatology and Venereology, 26(7), 863-869.
Guo, S., et al. (2018). Glycerol monolaurate-loaded liposomes as a drug delivery system for transdermal delivery: The effect of liposomal size. International Journal of Pharmaceutics, 536(1), 112-119.
Kim AV, Shelepova EA, Evseenko VI, Dushkin AV, Medvedev NN, Polyakov NE. Mechanism of the enhancing effect of glycyrrhizin on nifedipine penetration through a lipid membrane. J Mol Liq. 2021 Dec 15;344:117759.
Jafar Akbari, Majid Saeedi, Davood Farzin, Katayoun Morteza-Semnani
& Zahra Esmaili (2015) Transdermal absorption enhancing effect of the essential oil of Rosmarinus officinalis on percutaneous absorption of Na diclofenac from topical gel, Pharmaceutical Biology, 53:10, 1442-144
Moghimipour, E., et al. (2012). Rosmarinus officinalis L. as a penetration enhancer in transdermal drug delivery system. Research in Pharmaceutical Sciences, 7(5), S967