Put on a coat of lipstick, and most of it will eventually disappear.

Some rubs onto a glass. Some lands on a napkin. Some wears away.

And some of it may be swallowed.

That simple fact led researchers at the University of California, Berkeley to ask an intriguing question:

What exactly is inside the lip products people use every day?

In a study published in Environmental Health Perspectives, researchers tested 32 lipsticks and lip glosses for nine different metals.¹

Across the products, they detected all nine.

Several of these metals can be toxic at sufficient exposure.

And because lipstick is applied directly to the lips—again and again, sometimes for decades—this raises an obvious question:

Why should we accept unnecessary exposure to toxic metals in a product we may swallow?

There is an important scientific distinction to make here.

Finding a hazardous substance does not automatically prove that a particular exposure will cause harm. The concentration matters. The amount absorbed matters. The route of exposure matters.

But the opposite mistake can be just as serious.

Not proven harmful does not mean proven safe.

When potentially toxic substances are found in products we repeatedly put on our bodies, uncertainty should not automatically be interpreted in favor of continued exposure.

If the exposure is unnecessary and safer alternatives can be found, precaution offers another path:

reduce the exposure while scientists continue investigating.

WHAT SCIENTISTS FOUND INSIDE 32 LIP PRODUCTS

The investigation began with young women in Oakland, California.

Researchers asked members of a youth program to record the lipsticks and lip glosses they and their sisters were actually using. The researchers then purchased 32 of those products from stores.

There were eight lipsticks and 24 lip glosses from seven companies, ranging in price from $5.59 to $24.¹

Back in the laboratory, the researchers chemically broke down the products and analyzed them using an instrument capable of detecting and measuring individual elements.

They searched for nine metals:

• Aluminum
• Cadmium
• Cobalt
• Chromium
• Copper
• Manganese
• Nickel
• Lead
• Titanium

Across the 32 products, every one of those metals was detected in at least some samples.¹

Manganese, titanium and aluminum were detected in every product tested.

Lead was detected in 24 of the 32 products.

But the concentrations varied greatly from one product to another.

HAZARD IS NOT THE SAME AS RISK

Imagine that a laboratory discovers a potentially toxic substance in a glass of water.

Does its presence alone tell you whether drinking the water will hurt you?

No.

You need to know how much is there.

A substance capable of causing harm at a high dose may pose a very different risk at a tiny exposure.

This is one of the most important principles in toxicology:

Hazard and risk are not the same thing.

A hazard is something capable of causing harm under some circumstances.

Risk asks:

How likely is that harm at the exposure people actually receive?

That is why the Berkeley researchers went beyond simply asking whether metals were present.

They estimated how much of those metals people might actually ingest through normal lip-product use.¹

But there is another principle we should never forget:

Uncertainty is not the same as safety.

Knowing that hazard does not automatically equal risk protects us from unnecessary fear.

Knowing that uncertainty does not equal safety protects us from unnecessary exposure.

Both ideas matter.

HOW MUCH LIPSTICK DO PEOPLE USE?

The researchers used previous cosmetic-use data to estimate two levels of exposure.

Average lip-product use was about 24 milligrams per day.

For people at the high end of use—the 95th percentile—the estimate was 87 milligrams per day.¹

Then they made a conservative assumption:

They assumed that all of the lip product applied was eventually ingested.

Using the concentration of each metal measured in the laboratory, they calculated how much of each element a person could consume every day.

Those estimates could then be compared with health-based intake values.¹

This is where the investigation became considerably more concerning.

FOUR METALS STOOD OUT

Based on the researchers’ calculations, four metals deserved particular attention:

• Aluminum
• Cadmium
• Chromium
• Manganese

At average product use, estimated intake from some products exceeded 20% of the acceptable daily intake values the researchers derived for these metals.¹

Chromium stood out most strongly.

At average use, 10 of the 32 products produced estimated chromium intakes exceeding the researchers’ derived acceptable daily intake.¹

At the high-use estimate, some calculated exposures became larger still. The researchers reported estimated intakes exceeding their comparison values for aluminum in 3% of products, chromium in 68% and manganese in 22%.¹

Those are not results that should simply be waved away because the study did not demonstrate disease.

It could not demonstrate disease.

This was an exposure study. Researchers measured metals and estimated intake. They did not follow thousands of lipstick users for decades and compare their health with people who did not use those products.

So the absence of demonstrated illness in this study is not evidence that chronic exposure is harmless.

What the researchers did demonstrate is important enough:

Some lip products contained potentially toxic metals at concentrations that produced concerning exposure estimates under the researchers’ model.

That is a legitimate reason to want less exposure.

WHAT ABOUT LEAD?

Lead has probably received more attention in lipstick than any other metal.

And the Berkeley researchers did find it.

Lead was detected in 75% of the products. The average concentration was approximately 0.36 parts per million, while the highest measured concentration was 1.32 parts per million.¹

But lead was not the metal that stood out most strongly in this particular exposure analysis.

The researchers’ estimated lead intake remained below 20% of their derived acceptable daily intake at both average and high product use.¹

That distinction matters if we want to understand the study accurately.

But it does not make lead something we should want in lipstick.

WHY DOES LEAD STILL MATTER?

Lead is a well-established toxic metal, and reducing unnecessary exposure remains an important public-health goal.²

Our exposure also does not necessarily come from one source.

We encounter substances through food, water, air, dust, consumer products and other parts of our environment.

That means the question is not merely:

Is the amount in this one product enough to poison me?

There is another useful question:

If this exposure is unnecessary, why accept more of it than we have to?

That is particularly reasonable for a substance such as lead, where minimizing avoidable exposure is already a public-health objective.

THE FDA TESTED HUNDREDS MORE COSMETICS

The Berkeley investigation contained only 32 products.

The U.S. Food and Drug Administration later assembled a much larger body of testing data on lead in cosmetics.

Across its surveys, FDA obtained results for 685 cosmetic lip products and externally applied cosmetics sold on the U.S. market.^2,3

In the cosmetic lip products it analyzed, FDA reports lead concentrations ranging from below the detection limit to about 7 parts per million.²

Across all of the cosmetic lip products and externally applied cosmetics in its surveys, more than 99% contained less than 10 parts per million of lead.²

FDA has issued draft guidance recommending a maximum of 10 parts per million of lead as an impurity in cosmetic lip products and externally applied cosmetics.³

This is a recommended maximum—not permission to deliberately add lead to lipstick, and not a legally binding concentration limit.

Lead can enter cosmetics as an impurity because it occurs naturally in the environment and can be present in some raw materials, including mineral ingredients and pigments.

FDA concluded from its exposure assessment that lead at 10 parts per million in cosmetic lip products would not pose a health risk, while encouraging manufacturers to achieve lower levels whenever feasible.³

That provides important perspective on the concentrations found in the Berkeley study.

But regulatory guidance and personal precaution answer slightly different questions.

A regulator must decide what level of contamination it considers acceptable across an enormous market.

An individual can ask something simpler:

What exposure do I want for myself when I have a choice?

A recommended maximum should therefore not become a target.

If manufacturers can reliably produce lip products containing lower levels of unwanted toxic metals, lower is the direction worth pursuing.

WHAT ABOUT TITANIUM?

The original 2013 version of this article described titanium found in the products as a carcinogen.

That statement needs an important correction.

The effects of a substance can depend not only on what it is, but also on its chemical form, dose and route of exposure.

The cancer concern surrounding titanium dioxide has centered particularly on inhalation of particles into the lungs.

That is not equivalent to showing that titanium detected in lipstick causes cancer when the product is used normally.

And there is an additional distinction: the Berkeley researchers measured elemental titanium. That measurement alone does not establish the precise chemical form in which all of that titanium existed.

This is exactly where a precautionary approach must remain scientific.

Precaution does not mean assuming every uncertain substance causes harm.

It means accurately describing what we know, admitting what we do not know and deciding how much unnecessary uncertainty we are willing to accept.

SO SHOULD YOU BE CONCERNED?

We think these findings give consumers a legitimate reason to be concerned—and to act cautiously.

The study did not prove that conventional lipstick causes cancer, neurological disease or heavy-metal poisoning.

We should not claim that it did.

What it found is concerning enough without exaggeration.

Researchers detected nine metals across 32 ordinary lip products. Several can be toxic at sufficient exposure. And for aluminum, cadmium, chromium and manganese, estimated exposures from some products became substantial enough to attract particular attention from the researchers.¹

Meanwhile, the study did not establish the long-term safety of repeatedly using these products for years or decades.

That leaves us with uncertainty.

There are two ways to respond to it.

We can continue exposing ourselves and wait until science provides much stronger evidence that something is harmful.

Or, when the exposure is unnecessary and alternatives are available, we can reduce it while we wait for stronger evidence that it is safe.

We favor the second approach.

For an informed consumer, that means seeking lip products with credible independent testing for toxic metals and favoring products with the lowest reliably measured levels.

It does not mean that a product marketed as “natural,” “clean” or “non-toxic” is automatically safer. Those words alone tell us almost nothing about its actual metal content.

Testing does.

And because trace contamination can sometimes be unavoidable, demanding a literal concentration of zero is not always scientifically meaningful. The practical objective is to drive unnecessary exposure as low as reasonably achievable.

The burden should not be on consumers to prove that decades of exposure will hurt them before deciding they would rather avoid it.

When the exposure is unnecessary, potentially harmful and scientifically uncertain, precaution is a rational choice.

THE RULES HAVE CHANGED TOO

The regulatory landscape surrounding cosmetics in the United States has also changed substantially since this study appeared.

In 2022, Congress passed the Modernization of Cosmetics Regulation Act, known as MoCRA.

The law significantly expanded FDA’s authority over cosmetics.⁴

Among other provisions, companies responsible for cosmetic products must maintain records supporting adequate safety substantiation, while the law introduced requirements involving facility registration, product listing and serious adverse-event reporting.⁴

FDA also gained additional authorities, including access to certain records and mandatory recall authority under specified circumstances.⁴

These are meaningful improvements.

But regulation does not eliminate the need for scientific curiosity—or informed consumer choice.

Better testing and greater transparency can allow consumers to compare products and reward manufacturers that minimize unnecessary contamination.

WHAT A TUBE OF LIPSTICK CAN TEACH US ABOUT SCIENCE

There is something remarkable about this story.

A tube of lipstick may look simple.

Yet modern instruments can take a tiny sample of it, break it apart and reveal elements present at concentrations measured in parts per million.

We have become extraordinarily good at discovering what the world around us is made of.

But that power creates a new challenge.

Detection is not understanding.

Finding a substance is the beginning of an investigation—not the end.

To understand what a discovery means, scientists must follow the trail from presence, to concentration, to exposure, to absorption, to biological effect.

That protects us from becoming frightened every time an instrument detects a hazardous substance.

But good science must protect us from the opposite mistake too.

The absence of proof of harm is not proof of safety.

Science rarely hands humanity perfect knowledge before we have to make decisions.

We make choices while evidence is accumulating.

Sometimes waiting is reasonable.

But when an exposure is unnecessary, potentially harmful and reasonably avoidable, waiting for people to become sick before reducing it is not the only rational response.

We can ask for better evidence.

We can ask manufacturers for better testing.

We can choose products with lower measured contamination.

And we can change our minds as new evidence arrives.

That is not fear.

That is precaution guided by evidence.

And the lesson extends far beyond lipstick—to the food we eat, the water we drink, the air we breathe and the thousands of substances modern humans encounter throughout their lives.

Our instruments can now reveal parts of the world that previous generations could barely have imagined measuring.

The next challenge is deciding what to do with that knowledge.

Perhaps the wisest rule is also one of the simplest:

Follow the evidence as far as it goes. Never claim more than it proves. But when an unnecessary exposure could harm us and important uncertainty remains, we do not have to volunteer to be the experiment.

REFERENCES

1. Liu S, Hammond SK, Rojas-Cheatham A. Concentrations and potential health risks of metals in lip products. Environmental Health Perspectives. 2013;121(6):705–710. doi:10.1289/ehp.1205518.
2. U.S. Food and Drug Administration. Lead in Cosmetics.
3. U.S. Food and Drug Administration. Supporting Document for Recommended Maximum Lead Level in Cosmetic Lip Products and Externally Applied Cosmetics; and Draft Guidance for Industry: Lead in Cosmetic Lip Products and Externally Applied Cosmetics: Recommended Maximum Level.
4. U.S. Food and Drug Administration. Modernization of Cosmetics Regulation Act of 2022 (MoCRA).