Skincare and Cosmetics Myth Busting: 60% of products absorb into the bloodstream

The 60% Absorption Myth in Skincare

And why it refuses to die

Here we go again. Another one of my pet peeves...
I know, I have a few. But I genuinely care about spreading good information and the truth, and unfortunately there is a lot of bad information floating around the internet.

This is one I see constantly, and it bothers me for a very specific reason.

The myth

“The majority of ingredients in cosmetics absorb into the bloodstream.”

Most often, I see this paired with the claim that 60% of what you put on your skin ends up in your blood. I have even seen claims as high as 100%. That number is almost always stated confidently, rarely sourced, and frequently repeated.

It is also incredibly effective at scaring people.

Have you seen this number pushed by people or businesses?

It sounds terrifying, doesn’t it? And fear is a powerful marketing tool. This myth is most aggressively promoted by brands and influencers selling “natural” skincare, often at a premium price point.

Now here’s the part that surprises people.

I sell [mostly] natural skincare.

So why would I want to bust a myth that directly benefits my business?

Because I value the truth more than profits, and I am not willing to mislead people in order to sell products. Ever.

Your skin is not a sponge

Let’s start with the basics.

Our skin is not a passive, porous surface. It is a living, dynamic organ designed first and foremost to protect us. It has many layers, each with a specific function.

The outermost layer, the stratum corneum, is especially important. This layer is responsible for limiting what enters the body. It is incredibly effective at doing its job. The stratum corneum is composed of flattened, keratin-filled cells embedded in a dense lipid matrix made up of ceramides, cholesterol, and fatty acids. Together, these components form a tightly organized structure that severely limits what can pass through.

This is often described as a “brick and mortar” system. The skin cells act as the bricks, and the lipids act as the mortar sealing the gaps. Unlike a sponge, which is porous by design, this structure is compact, layered, and deliberately resistant to penetration.

The vast majority of what comes into contact with the skin, never makes it past this layer. 

If human skin absorbed 60% of everything it touched, we would not survive very long.

Just think about everything your skin comes into contact with in a single day! Water, soap, clothing dyes, environmental contaminants, household surfaces, plants, animals, ocean water, dust, and countless other substances.

If even half of that entered the bloodstream, every shower would leave us dangerously riddled with edema. A swim in the ocean would be catastrophic. Daily life would overwhelm the body almost immediately.

That does not happen because skin is not designed that way. Our skin is incredibly selective. 

Even whens substances do pass through the stratum corneum, they typically do so in small amounts and can be slowed down, altered and stopped entirely by deeper layers of the skin. Reaching systemic circulation requires passing many physiological check-points, not just crossing the very surface.

The body continuously works to reinforce this protective layer by shedding old cells, producing protective lipids, and repairing microscopic damage.

Absorption is not the default state of skin. Protection is.

So what does affect absorption?

Absorption through the skin is real, but it is highly limited and influenced by several important factors.

1. Molecule size
For an ingredient to move through the skin, its molecules must be small enough to pass between skin cells. Many cosmetic ingredients are simply too large to do this effectively.

2. Polarity
Skin is made of both water-loving and oil-loving components. An ingredient must have the correct balance of water and oil solubility to move through these layers. If it is too water-soluble or too oil-soluble, penetration is limited.

3. Skin condition and environment
Humidity, temperature, and the overall health of the skin barrier matter. Damaged or compromised skin allows more penetration than healthy, intact skin.

4. Skin type
Skin type plays a significant role. Dry skin often has a weaker barrier and may allow slightly more penetration. Oily skin typically has a stronger barrier, which can reduce penetration.

5. Location on the body
Not all skin absorbs at the same rate.

Skin thickness and barrier strength vary significantly across the body. Areas with thinner skin and higher blood flow allow greater penetration than areas with thicker, more keratinized skin.

For example, absorption tends to be higher on areas such as the face, scalp, underarms, and groin, and much lower on areas like the palms of the hands, soles of the feet, elbows, and knees.

This variation is one of the reasons broad claims about “how much absorbs” are misleading. An ingredient applied to the forearm behaves very differently than the same ingredient applied to the eyelid or the sole of the foot.

Regulation reflects these realities..

These differences in absorption are not theoretical. They are formally recognized and regulated.

One of the clearest examples of this is the International Fragrance Association (IFRA) standards. IFRA does not regulate fragrance ingredients with a single universal limit. Instead, it assigns different usage limits depending on where and how a product is applied.

IFRA divides cosmetic products into categories based on:

• The part of the body where the product is used

• Whether the product is leave-on or rinse-off

• Duration of contact with the skin

• Likelihood of occlusion or repeated exposure

For example, a fragrance ingredient may be allowed at a higher percentage in a rinse-off body wash than in a leave-on facial product. The same ingredient may have a much lower allowable concentration for products used on the lips, underarms, or intimate areas.

This tiered system exists precisely because absorption and sensitization risk vary by body location and use pattern. If skin absorbed ingredients uniformly across the body, these distinctions would be unnecessary.

IFRA standards also highlight another important point. Regulation focuses heavily on local skin exposure and sensitization, not systemic absorption. The concern in most cosmetic safety assessments is irritation, allergic response, and cumulative skin exposure, not widespread entry into the bloodstream.

This is yet another reason why claims like “60% of what you put on your skin is absorbed” do not hold up under scrutiny. The science, and the regulations built on that science, recognize that skin behaves very differently depending on context.

Even in areas with higher permeability, absorption into the bloodstream remains limited. Increased penetration does not automatically mean systemic exposure.

Even with all of these factors aligned, penetration is still limited.

Natural vs synthetic does not equal safe vs unsafe

Both natural and synthetic ingredients can penetrate the skin. What matters is which ingredient is being used, how much is being used, and how it is formulated.

Every cosmetic ingredient, regardless of origin, has established safety data and recommended usage levels. These guidelines exist for a reason. Ignoring them can cause irritation, sensitization, or long-term skin damage.

One of the biggest ironies in this conversation is essential oils.

Essential oils are natural, but they are also among the ingredients most capable of penetrating the skin. They are frequently used carelessly under the assumption that “natural” automatically means safe.

It does not.

Absorption vs penetration (this part matters)

These two terms are often used interchangeably, but they are not the same thing.

Penetration refers to an ingredient entering the upper layers of the skin. This is what a well-formulated cosmetic product aims to achieve. Active ingredients need to penetrate into the skin to be effective.

Absorption refers to an ingredient moving beyond the skin and into the bloodstream.

This article is focused primarily on absorption.

While some absorption does occur, research consistently shows that far less than 10% of cosmetic ingredients reach the bloodstream. Often it is much less than that.

This is also why transdermal medications represent only a small fraction of pharmaceutical delivery methods. Getting substances through intact skin and into systemic circulation is difficult by design.

The bottom line

The stratum corneum is a complex, intelligent, and highly effective barrier. It is our anatomical armor.

That does not mean topical products are risk-free. Reactions can and do occur within the layers of the skin, and those reactions are highly individual. Knowing your skin, paying attention to how it responds, and using products appropriately always matters.

But the claim that most cosmetic ingredients enter the bloodstream is simply not supported by science.

Fear may sell products, but it does not make something true.

References

1. Brisson, Paul. Percutaneous Absorption
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1947480/
2. https://onlinelibrary.wiley.com/doi/full/10.1002/anie.202107960
3. International Fragrance Association (IFRA)
   IFRA Standards and Categories
   https://ifrafragrance.org/safe-use/introduction-to-ifra-standards