04/13/2026
In a study of 26 women, levels of a nail polish chemical metabolite increased up to 7x in urine within 10–14 hours after application.
Not from breathing it in…
From direct absorption through the nail and surrounding skin.
That compound is triphenyl phosphate (TPHP).
It’s commonly used in nail products to improve flexibility and durability, but it also belongs to a class of chemicals known to interact with hormone pathways.
Here’s why this matters:
• DPHP (a metabolite of TPHP) is detected in over 97% of the U.S. population
• Nail salon workers show significantly higher levels (reported up to ~4x in some studies)
• Lab data shows TPHP can mimic estrogen and interfere with testosterone signaling
• It also interacts with thyroid hormones and pathways involved in fat storage
Human research is still developing, but higher exposure has been associated with:
• Changes in fertility-related markers in both men and women
• Poorer embryo quality in IVF settings
• Hormone shifts tied to reproductive health
Labels like “non-toxic” or “10-free” aren’t tightly regulated, and some products may still contain TPHP or similar substitutes.
This doesn’t mean you need to avoid everything.
But if this is something you use regularly, it may be worth being more intentional:
• Look for brands that clearly state TPHP-free
• Reduce frequency of use when it feels aligned
• Improve ventilation in home or salon settings
Small exposures, repeated over time, tend to matter more than one-off use.
What’s one product you’ve already swapped — or are you thinking about changing?
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