Next time you’re stocking up on your beauty essentials, it might be time to do some serious research on the ingredients in your bottle of nail polish. A new report published by Marie Claire has pointed to ingredients in your nail polish interfering with hormones… which could lead to weight gain. Researchers at Duke University and the Environmental Working Group examined the effects of adding triphenyl phosphate (or TPHP) to the beauty solution. TPHP, which is used to make polishes more flexible and durable, is also used to make plastic. But researchers have found that the substance can interfere with hormones with tests on animals linking the ingredient to reproductive and developmental problems. In humans, scientists claim the ingredient could lead to weight gain and are now researching the effects more intensely. Publishing the results in the journal Environment International, the team tested the urine of 26 participants before and after they painted their nails, despite the polishes having just 1 percent TPHP in its bottle. The results pointed to 24 of the participants having elevated levels of the chemical in their body within two to six hours, while every single participant had increased levels by nearly seven times within 10-14 hours. The chemical (which is present in more clear polishes than coloured ones), was found in 49 percent of the 3,000 polishes collected by researchers. The Environment Working Group has now launched a petition asking nail polish producers to remove TPHP from its products.