The first few years of menstruation can be unpredictable. A period might arrive after three weeks, then disappear for six. One month might be relatively light, while the next is surprisingly heavy. Or they might start heavy and just arrive each time as different versions of heavy. There can be a physiological reason for some of this variation. When periods first begin, the communication pathways between the brain and ovaries are still maturing. Known as the hypothalamic–pituitary–ovarian axis, this communication coordinates ovulation and the menstrual cycle.

During these early years, ovulation doesn’t necessarily happen every cycle. Without ovulation, the usual rise in progesterone doesn’t occur, while estrogen continues to lay down the uterine lining. This can result in irregular, prolonged or heavier bleeding. In fact, anovulatory cycles are the most common cause of heavy menstrual bleeding in adolescents.

Sometimes the cycle needs time to find its rhythm

As the communication between the brain and ovaries matures, menstrual cycles tend to become more regular. By the third year after the first period, around 60-80 percent of menstrual cycles are 21–34 days long, which is typical of adult cycles. So, some irregularity in the first few years of menstruation can be part of normal development. Yet there’s an important distinction here: common doesn’t mean something should automatically be ignored. ****Heavy menstrual bleeding can have consequences of its own and one of the biggest is iron loss.

Heavy periods and iron deficiency often go hand in hand

Every time we bleed, we lose iron. Even a ‘normal’ menstrual flow of around 60 mL of blood per cycle, roughly 12 tampons or pads, give or take, can mean losing around 27–30 mg of iron. When a teenage girl is experiencing heavier or more prolonged periods, you can see how quickly those losses can begin to exceed what she is able to replace through food alone.

Heavy menstrual bleeding is a recognised risk factor for iron deficiency in adolescents. This is why checking iron status, including ferritin, can be an important part of investigating heavy periods. And iron deficiency doesn’t have to progress to anaemia before it has consequences. Low iron stores are associated with fatigue, anxiety, and changes in cognition and concentration. In a teenager, these can be very easy to explain away.

She’s tired because she stays up too late. She can’t concentrate because she’s distracted. She’s anxious because she cares about her grades. She’s exhausted after sport because she’s doing too much. Sometimes those explanations may be true. But if she is also experiencing heavy periods (or she’s not eating enough), her iron status is important to investigate.

Replenishing what’s being lost

If testing confirms that her iron stores are low (<50 mg/L), replenishing iron becomes a vital part of the picture. Food sources of iron remain foundational. But when someone is already iron deficient, food alone is usually not enough to restore iron stores and iron supplementation is typically necessary. Iconic Iron contains ferritin-iron sourced from organic peas and was formulated to support healthy iron levels when dietary intake alone isn’t meeting the body’s needs. It’s gentle on the tummy too, unlike many conventional iron supplements made from iron salts.

Of course, replenishing lost iron doesn’t answer another important question: why is she bleeding so heavily in the first place?

What might be driving the heavy bleeding?

As a nutritional biochemist, Dr Libby’s approach is to be curious about why a symptom is occurring, rather than focusing solely on making that symptom go away. Taking the contraceptive pill does not address the why – it masks it. It is far more beneficial to determine (and address) what might be driving the heavy bleeding in the first place. The hormonal scenario that most often drives heavy periods is low/no progesterone relative to estrogen, at a time in the cycle when the opposite is supposed to be true.

In the early years, it may be related to the normal maturation of the menstrual cycle we’ve described above – anovulatory cycles can be normal at first, however if this persists, determining why cycles continue to be anovulatory is very important. Common drivers include under-eating, over-exercising , Relative Energy Deficiency in Sports (REDs), nutrient deficiencies (including iron), high prolactin (usually due to stress), and Polyendocrine Metabolic Ovarian Syndrome (PMOS), which usually requires elevated androgens and insulin to be addressed. But anovulation (and its drivers) isn’t the only possible explanation for heavy periods. Thyroid dysfunction (under-activity) can also influence ovulation and menstrual bleeding (although in the teenage years, this is usually due to iron deficiency as the thyroid requires iron to produce its hormones), while heavy periods can occasionally be related to an underlying bleeding disorder.

This is why heavy or persistent bleeding deserves investigation rather than simply being dismissed as part of puberty. Reducing the bleeding and understanding why it is happening are both important, as is addressing the consequences of the heavy bleeding which may include iron deficiency.

When is a heavy period too heavy?

While irregular and anovulatory cycles can be common in the first few years after menstruation begins, very heavy bleeding shouldn’t simply be dismissed as part of puberty.

It’s worth speaking with an integrative GP or an experienced naturopath, medical herbalist or nutritionist if her periods:

• last longer than seven days
• require her to change a super pad or tampon more frequently than every two hours
• regularly leak through clothing or bedding
• are interfering with school, sport or everyday life
• are accompanied by significant fatigue, dizziness, breathlessness, anxious feelings, low mood, or other symptoms that could suggest iron deficiency or anaemia.

These aren't symptoms she simply has to put up with.

And if heavy periods continue?

If heavy periods persist as her menstrual cycle becomes more established, rather than accepting this as simply her normal, it’s worth exploring what might be driving them with an appropriately qualified and experienced healthcare professional. Once you have a clearer picture of what’s going on and the foundations have been addressed, additional nutritional support may also be helpful.

Cycle Essentials was formulated by Dr Libby, drawing on her understanding of the body’s biochemical pathways and what’s needed for a healthy menstrual cycle. Its carefully selected nutrients and herbal ingredients help to foster regular ovulation and hence progesterone production, support healthy adrenal function and ease common symptoms such as period pain.

Give her cycle time, but pay attention along the way

The early years of menstruation involve enormous change and the intricate communication involved in a menstrual cycle can take time to establish. What we don’t want to do is overlook what her body might need while that process unfolds. Pay attention to how much she is bleeding (via pad and/or tampon usage). Investigate bleeding that seems excessive or is affecting her quality of life. If her mood or disposition alters, don’t dismiss this as part of this stage of her life. Consider her iron status and replenish iron if she is deficient. Because a symptom is information. The more we understand about what’s driving it, the better placed we are to support her through these formative years.