The Truth About How Skincare Ingredients Get Absorbed Into the Skin
Despite what you may have heard, you can't fix split ends, and antiperspirants don't cause cancer. In Myth Busters, we debunk common beauty misconceptions and set the record straight.
Myths about beauty and skincare are inevitable. Some of these rumors are harmless—like shaving makes our hair grow back faster, which, spoiler alert, it doesn't. However, when lies about beauty products impacting our health get thrown around, we need to take them seriously and investigate whether they're true or not. Now, there's a popular myth going around Instagram, Reddit, and popular blogs that suggest that 60% of your skincare ingredients get absorbed into your bloodstream. That's a very scary statistic when you think about everything that's in your skincare products.
Licensed esthetician and famous skincare TikToker Charlotte Palermino said it best when she explained that if this were true, we'd all be heavily intoxicated from hand sanitizer, as most formulas include 60% alcohol at the minimum. Jokes aside, though, the truth is that the skin's primary function is to protect us, so the notion that a large portion of our skincare ingredients gets absorbed into our blood simply isn't true. There are some exceptions, but we'll get into that later.
To help us set the record straight, we tapped two cosmetic chemists to learn more about how the skin functions, how it absorbs skincare products, and the truth about whether it can get into our bloodstream.
How does the skin function?
To understand why this myth isn't true, we need to know how the skin works. Our skin is our largest and heaviest organ, and it has multiple functions. It consists of several different layers, and each one plays a particular role in protecting the body, explains Shuting Hu, P.h.D., a cosmetic chemist and founder of Acaderma. "The outermost layer of your skin, called the epidermis, works as a barrier, and it consists of strong skin cells called corneocytes," she says. She further explains that this layer of your skin is crucial to your overall health as it defends your body from any environmental threats while maintaining moisture and hydration by protecting the water in your body.
The second layer is known as the dermis, which is made of elastic collagen fibers. The purpose of this layer is to protect the deeper layers of skin and facilitate thermoregulation—the process of keeping your body at a constant temperature. The deepest layer of skin is the subcutaneous layer or hypodermis, and it's mostly fat and connective tissue that protect your bones and joints.
How does the skin absorb skincare products?
The way your skin absorbs skincare ingredients depends on many factors, including the type of ingredient used. "Biologically, the skin's outermost part is a phospholipid bi-layer (aka made of oils)," explains Krupa Koestline, clean cosmetic chemist and founder of KKT Consultant. Since oil and water don't mix, she says, "oil-soluble products and emulsions have an easier time penetrating than water-based ingredients."
Molecular size also plays a role. "Ingredients with a larger molecular size tend to stay on top of the skin while the smaller molecules can penetrate deeper," says Koestline. Ingredients such as vitamin C, vitamin E, vitamin B3, and hyaluronic acid all have relatively small molecular structures, says Dr. Hu. Similarly, certain oils tend to absorb easier while waxy substances sit on top of the skin.
Another factor to consider is where on the body you're applying your skincare. The thickness of the skin varies on different parts of your body, so its permeability will differ. Think about it: The skin on your face feels very different than the skin on your elbows. To understand more about how this works, here's a table from the book Percutaneous Absorption, which shows how hydrocortisone and two pesticides passed through skin in different locations on the body.
Despite all of the different contributors that can impact how the skin absorbs ingredients, Koestline explains that the skin is not a sponge. It doesn't just absorb everything because it has a small molecular size, or is applied on a more permeable area. "For transdermal absorption to occur, it's a complicated process," she says. "It's not as easy to just put something on your skin for it to penetrate, it takes a lot of testing, research, and development to develop transdermal drugs and cosmetics."
So, does skincare get into our bloodstream?
As with all things in science and skincare, there is no simple yes or no answer. Is it possible for skincare to get absorbed into your bloodstream? Yes. Is it likely—let alone a 60% chance? No.
The main function of the skin is to keep the bad things out, plus, skincare products are designed to be applied topically, so they don't even reach the deepest layers of our skin, writes Michelle Wong, a blogger, chemistry Ph.D. graduate, and Australia-based science educator who started the website Lab Muffin, which breaks down the science of beauty in simple terms.
For your skincare to absorb into the bloodstream, it would need to undergo several processes and layers of the body, explains Dr. Hu. "After it passes multiple layers of the skin, including the dead surface skin cells, which acts as a barrier, the ingredient has to get past your metabolic functions before it can reach the bloodstream," she says. "If 60% of skincare ingredients were absorbed by the bloodstream, I'd be rubbing salad and iron on my skin every day."
So, what about transdermal medications and patches, such as nicotine patches? These are formulated differently than skincare cosmetics, so it's possible for an ingredient to reach the bloodstream from topical application, explains Dr. Hu. However, studies show that 10 to 95% of the drug remains on the surface of the skin with the transdermal drug products currently on the market. So, the amount of ingredients getting absorbed into the skin isn't excessive or harmful.
"There's a lot of fear-mongering and misinformation about the dangers of skincare absorption," says Dr. Hu. "It takes a high dose and years of consistent administration for the most intense ingredients, like steroid hydrocortisone, to enter the bloodstream through the skin." Skincare cosmetics, like the serums, cleansers, you apply on your skin aren't formulated in the same way, meaning it's very unlikely for it to get into the bloodstream.
Koestline says our skin is our biggest defense weapon. "It's designed to keep things out of our body and out of our bloodstream. It's very difficult for skincare products applied topically to make it pass the several layers of skin."
Ultimately, Dr. Hu says you can assume that your skincare products are being properly absorbed into the skin when applied correctly because that's what they are designed to do. So, you can carry on with your 10-step skincare routine and multi-masking—rest assured that it's not going anywhere except your skin.