Chemicals In Personal Care Products May Trigger Early Puberty

Over the past few decades, doctors have observed that many girls are entering puberty at younger ages than they used to. This shift toward younger puberty timing is concerning because it has been linked to a greater likelihood of psychological stress, excess weight gain, diabetes, cardiovascular conditions, and breast cancer later in life. And while genetics certainly play a role, this rapid shift suggests that environmental factors may also be involved. A 2024 study published in Endocrinology by researchers at the National Institute of Environmental Health Sciences (NIEHS) explored this issue, inquiring into whether certain everyday chemicals could interfere with the brain signals that normally control when puberty begins.

Puberty is triggered by a carefully timed process in the brain involving two key receptors: the kisspeptin receptor and the gonadotropin-releasing hormone (GnRH) receptor. These receptors help “switch on” the reproductive system at the appropriate age. The researchers wanted to know whether environmental chemicals could accidentally flip this switch too early.

To investigate this question, the team screened nearly 10,000 chemicals commonly found in medications, consumer products, and the environment. Using human cells engineered to carry these receptors, they looked for substances that could activate them. They then conducted follow-up experiments in human brain cells, mouse cells, and zebrafish to see whether these chemicals triggered biological changes linked to puberty.

The study identified several concerning compounds. One was a fragrance ingredient called musk ambrette, which activated the kisspeptin receptor and increased signals associated with the start of puberty in lab models. Musk ambrette has been used in some perfumes and personal care products and is known from earlier studies to potentially cross the blood-brain barrier, meaning it has the ability to enter the brain. Due to potential health risks, musk ambrette is restricted under Canadian and European regulations, and it has lost its “generally recognized as safe” (GRAS) status in the United States. Nonetheless, it remains commercially available in some consumer products.

Other chemicals, similar in structure to certain nerve-stimulating drugs, were identified and seen to activate the GnRH receptor, switching on genes involved in reproductive hormone release.

Importantly, the researchers emphasize that these findings do not prove that these chemicals cause early puberty in children. The work was done in laboratory models, not in people. However, the results raise red flags and highlight the need for further research on how everyday chemical exposures may affect developing bodies.

The study also demonstrates a novel, faster method for testing large numbers of environmental chemicals for potential health effects. Until more is known, the authors suggest that parents may want to be cautious about children’s exposure to unregulated personal care products, especially those containing fragrances.