Why is Puberty Occurring Earlier Than in the Past?

The average age of puberty has been steadily decreasing since the 1970s, starting at younger ages than ever before. Studies in countries around the world have shown that the average age of puberty for girls has consistently dropped by about three months per decade over the last five decades. A similar but less aggressive pattern has also been observed in boys. 

Though the exact cause of this trend is still unknown, multiple risk factors have been identified. Obesity, stress, and, more recently, the impact of the COVID-19 pandemic have all been connected to early puberty and the rise in CPP cases. Still, exposure to these risk factors doesn’t necessarily mean a child will get CPP. If your child has experienced these risk factors, you haven’t done anything wrong, and treatment and support are available.


Studies have linked obesity to increased chances of CPP, particularly among girls. One of these studies focused on leptin, a hormone produced by insulin and fat cells. Leptin interacts with the part of the brain that controls appetite, and researchers discovered that it also impacts how the brain regulates growth and sexual maturation. 

It’s important to note that obesity does not cause CPP. Though it is believed that a high BMI is a possible contributing factor to early puberty, it is not a guarantee. Many children who are not obese still develop CPP, and many who are considered overweight do not. 


While the US blamed obesity for the rise in CPP cases, other countries were seeing a similar increase but with no discernible difference in the BMI of their children through the years. An alternate theory emerged, suggesting that exposure to endocrine-disrupting chemicals may be contributing to early puberty. Endocrine disruptors can affect the behavior of hormones and are found in all kinds of everyday products, making it difficult (if not impossible) to avoid them. Many scientists are skeptical of this theory due to a lack of data; currently, there is not enough evidence to show a clear connection between endocrine-disrupting chemicals and CPP.


There is also evidence that adversity and stress are connected to early onset puberty. A joint study between the University of Pennsylvania and the Children’s Hospital of Philadelphia has linked childhood poverty, conflict, and trauma to cases of accelerated puberty and brain maturation. So, in addition to the external physical changes a child’s body may experience during puberty, their research also showed abnormal brain development. Untreated CPP can also contribute to a child’s stress, as demonstrated by a 2017 study that showed a significant reduction in stress levels after undergoing CPP treatment.

Just remember, stress and trauma are not necessarily the result of an unhappy home life. Children are exposed to many different situations that are out of your control. These experiences don’t change the fact that you’re an amazing parent.


Since the start of the pandemic, CPP cases have risen worldwide. A rare condition, CPP only affects about one in 5,000 – 10,000 children, which is why this spike in cases is so significant. 

Indirect causes of this surge may include the stress, grief, and lifestyle changes accompanying the pandemic. One early study suggests that a combination of lockdown-induced environmental factors contributed to this increase, including higher BMI and increased use of electronics due to a more sedentary lifestyle. 

The added stress from the pandemic may be another factor—not just the psychological toll of lockdown but coping with grief after losing loved ones. With families confined to their homes, it’s also possible that parents have been spending (a lot) more time with their children, giving them the opportunity to notice early puberty symptoms. Ultimately, the pandemic has uniquely combined several known lifestyle and environmental risk factors for CPP, possibly leading to more cases.

Despite all of this research, there is still no clear, single indicator connected to the progressively earlier onset of puberty. Puberty is occurring earlier, but that is not necessarily the same as CPP, which typically begins before age eight. If your child is or has been diagnosed with CPP, there are many paths forward. Remember that it’s not your fault; it’s the result of a complex combination of factors that scientists have yet to fully understand. Focus on your child and caring for them (and yourself).

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