From the Perspective of a Nearly 25 years Licensed Beauty Professional and a Former U.S. Territory Director in Professional Beauty

I spent over 15 years behind the chair as a stylist.
I also spent more than a decade running the U.S. territory of an international hair color company, overseeing education, product use, and professional standards across the country.

I wore nail polish.
I performed manicures and pedicures.
I worked hands-on with professional beauty products nearly every day.

At no point during the past 25 years of professional immersion did anyone explain that a single manicure could measurably increase a hormone-disrupting chemical in the body within hours.

That information came later — from the science.

The Study Every Beauty Professional Should Know

In a peer-reviewed human study of 26 women, researchers evaluated exposure to triphenyl phosphate (TPHP), a chemical commonly used in nail polish.

After one manicure, levels of DPHP (TPHP’s primary metabolite) were found to increase up to seven-fold in urine within 10–14 hours.

The most important finding:

This exposure did not occur through inhalation.
It occurred through direct absorption via the nail plate, nail bed, and surrounding skin.

Ventilation does not address this pathway.

PMID: 26485058

What Is TPHP, Exactly?

Triphenyl phosphate (TPHP) is added to many nail products to:

• Improve flexibility

• Reduce cracking and chipping

• Enhance shine and wear time

Chemically, it belongs to a class known as organophosphate esters — compounds that have been widely studied for their ability to interact with hormone signaling pathways.

Once absorbed, TPHP is metabolized into DPHP, which is what researchers measure to assess internal exposure.

How Common Is Exposure?

According to CDC biomonitoring data from NHANES (2011–2020):

• DPHP is detected in over 97% of Americans

This confirms that exposure is widespread, even outside salon environments.

PMID: 30396558

Occupational Exposure: Salon Professionals Are Different

Multiple studies show that nail salon workers experience substantially higher exposure levels:

• Urinary DPHP concentrations measured at up to four times higher than the general population

This matters because frequency and repetition increase cumulative endocrine burden.

PMID: 28437481

What the Mechanistic Science Shows

In laboratory and cellular models, TPHP has been shown to:

• Mimic estrogen signaling

• Inhibit androgen (testosterone) activity

• Alter thyroid hormone pathways

• Activate PPAR-γ, a receptor involved in fat storage and metabolic regulation

These findings explain how exposure could influence hormone-regulated systems. They do not claim certainty — they explain biological plausibility.

PMID: 30396558

Human Associations Linked to Higher Exposure

Human observational studies associate higher exposure to organophosphate esters (including TPHP/DPHP) with:

• Increased risk of pregnancy loss

• Reduced embryo quality in IVF contexts

• Altered sperm morphology

• Lower testosterone levels

• Reduced fertility outcomes in both sexes

These are associations, not guarantees — but they are consistent across multiple studies.

PMID: 39320888
PMID: 40200288

The Labeling Gap in Beauty Products

One of the most difficult truths for professionals to accept:

Even products marketed as “non-toxic,” “clean,” or “10-free” may still contain:

• TPHP

• Closely related organophosphate substitutes

• Plasticizers with similar endocrine activity

This occurs because:

• Full ingredient disclosure is often not required

• Functional additives may fall under fragrance or proprietary blends

• Marketing claims are not the same as toxicological testing

Who May Want to Pay Closer Attention

Based on current evidence, increased caution may be warranted for:

• Daily nail polish users

• Nail salon workers and educators

• Individuals planning to conceive

• Those managing hormone or thyroid conditions

This is about awareness, not alarm.

Why I’m Sharing This

I share this as someone who:

• Worked hands-on in beauty for 15 years

• Led a professional hair color territory at a national level for over a decade

• Trusted the systems that trained us

No one told us to consider nail polish as a hormone exposure pathway.

Now the data exists.

One Question to Leave You With

You do not need to overhaul your life to reduce exposure.

What is one swap you’ve made — or are considering — to reduce toxin exposure in your daily routine?

Sources (PubMed)

• PMID: 26485058
• PMID: 28437481
• PMID: 30396558
• PMID: 39320888
• PMID: 40200288