Walking into Safeway, a Paly junior, who asked her name not be used because of the sensitivity of the topic, strides down the menstrual products aisle with her mother and sister. While she blankly stares at all the products, her mom and sister quickly begin grabbing different-sized pads and tampons from the shelves and placing them into the cart. Once home, they start explaining to her what she is experiencing and what the pads and other products are for.

“As my sister had already gone through her first period, I had already been able to observe some of what I would come to experience when I got it and had some level of preparedness,” the junior said. “But when it finally did happen, I was very thankful for them as they walked me through everything I needed to know, from what size of pads to get to the symptoms that would come with it.”

Girls, as well as transgender and nonbinary individuals who menstruate, often experience irregular or early periods. In recent years, there has been a noticeable increase in“precocious puberty,” where girls start puberty before the age of eight.

In fact, the average age of the first menstrual cycle, called menarche, is much earlier than in previous generations, with the average age of puberty decreasing by three months per decade over the past 45 years according to a study by PubMed Central. Also, 10 to 15% of girls enter puberty at age seven or younger.

Dr. Faezeh M. Ghaffari, a gynecologist at Kaiser Permanente, said the onset of puberty occurs a few years before a person’s first period, but environmental factors can cause menarche much earlier in some people.

“So many of my friends’ little sisters have been getting their periods earlier than we did while still having to deal with not being prepared, as many schools have not yet adjusted sex education courses yet,” Ghaffari said. “I also feel many don’t know what is happening to them and why it is happening, as we learn in biology that there is a biological timeline that should normally be followed during the beginning of puberty.”

Ghaffari said multiple biological factors can determine the age at which puberty starts for girls, with many being interconnected such as pubic hair growth, increase in height and the addition of fat storage. However, the first factor to consider, he said, is a girl’s environment and what they were exposed to as an embryo, which can determine which hormone will be most prevalent during puberty.

“While they’re still inside their mother, they’re exposed to different environments, and their body may be exposed from those gonads (from their mother) to different hormones,” Ghaffari said. “The pituitary gland, which is also in the brain, starts releasing stimulating hormones called LH and FSH.”

Ghaffari also said many girls today experience premature menstruation primarily because of obesity and its impact on bone structure, as well as earlier production of LH and FSH.

 “Having excess body fat in prepubertal age can result in skeletal maturation before we reach our maximum heights,” Ghaffari said. “The long bones have plates at the end of them that are responsible for growing, and as long as those bone plates are immature, we continue to grow taller. (But) having excess fat as a young girl can expedite the bone plate closing off earlier and (start) the whole process of puberty at a younger age.”

Beyond excess body fat, Ghaffari said chronic stress is a factor in determining when menarche will be reached.

“If our body perceives that we’re in danger, or we’re under stress (and) we’re not able to protect ourselves, the last thing it wants to do is for us to get pregnant,” Ghaffari said. “Sometimes when you’ve already been through menarche, and you’ve had periods, but you go through a very stressful period, like a chronic disease or even long travel that completely throws you off your cycle, you may miss your periods for some time because your body protects you from ovulation.”

For a Paly sophomore, who didn’t want her name used because of the sensitivity surrounding the topic of puberty and menstruation, menarche struck earlier than expected, leading to feelings of being unprepared and confused by the sudden changes.

“It all happened so quickly,” the sophomore said. “I was one of the first in my grade to get it and did not know what to expect. I did not know exactly what to buy or what symptoms I would have. “I began becoming more moody and often felt isolated from others because they had not yet experienced what I had and had little to no idea about what I was going through.”

According to Ghaffari, many young girls also reach menarche earlier than in previous decades for the opposite reason — in modern society, there is less overall stress as we live longer, have extended times of peace, effective medicine and stable economies.

Although many young girls can complete regular exercise, stick to a healthy diet and minimize stress to try and mitigate precocious puberty, these actions are a small factor in determining the early onset of menarche compared to genetics.

The anonymous junior said rather than focusing on how to prevent “precocious puberty,” people should focus on what can be done to help mitigate the effects of the menstrual cycle and destigmatize it.

“Menstruation is a topic that needs to be more normalized to talk about to men and women alike so women and men are both comfortable when situations arise regarding periods,” the junior said. “And, as girls are getting their periods earlier, it needs to be talked about earlier. (We) don’t want young girls to believe something is wrong with them or isolate themselves as they can’t relate with others about it.”