A missing period is a signal, not a diagnosis. Amenorrhoea is the absence of menstruation, and the work is finding which part of the reproductive hormone pathway has gone quiet and why.

What is amenorrhoea?

There are two forms:

• Primary amenorrhoea: menstruation that never started by the expected age.
• Secondary amenorrhoea: periods that were previously established stop for three months or more (longer in someone with irregular cycles).

A regular cycle depends on a chain of communication: the hypothalamus releases GnRH in pulses, the pituitary responds with LH and FSH, the ovaries produce oestradiol and progesterone, and the uterine lining responds by building and shedding. Amenorrhoea means a break somewhere in that chain, or an anatomical block at the end of it.

Potential causes

Pregnancy and breastfeeding are always the first considerations. Beyond that, causes group by where the disruption sits.

• Hypothalamus: under-eating, low body fat, intense training, prolonged stress or rapid weight loss. The brain reads low energy availability or high threat and slows GnRH pulses, so LH, FSH and oestradiol fall.
• Pituitary: raised prolactin (including from medications) or pituitary growth or damage. Excess prolactin suppresses GnRH and ovulation.
• Ovary: PCOS involves anovulation with androgen excess. Primary ovarian insufficiency is early loss of follicle function, with high FSH.
• Thyroid: both hypothyroidism and hyperthyroidism can disrupt GnRH signalling, SHBG and prolactin regulation.
• Uterus and outflow: scarring after surgery or infection, cervical narrowing, or structural differences present from birth. Hormones work normally, but blood cannot be shed or the lining cannot respond.
• Medications and contraception: recent cessation of the pill, a hormonal IUD, antipsychotics and some chemotherapy can suppress the axis directly or delay the return of ovulation.

What we investigate as naturopaths

The aim is to identify the level of the disruption and the driver behind it, then coordinate testing and care with the GP where needed.

• Cycle history: age at first period, past cycle pattern, time since the last period and contraceptive history. This separates primary from secondary amenorrhoea and flags post-pill recovery.
• Energy and load: dietary intake, weight changes, training volume, sleep and stress load, to identify functional hypothalamic suppression.
• Pregnancy: a pregnancy test comes before anything else.
• Reproductive hormones: FSH, LH, oestradiol and prolactin help locate the break: hypothalamic, pituitary or ovarian.
• Androgens: testosterone, SHBG and DHEAS, alongside signs such as acne, excess hair growth and scalp hair thinning, point toward PCOS.
• Thyroid: TSH, with free T4 as indicated, excludes thyroid-driven disruption
• Metabolic markers: fasting glucose, insulin and ferritin. Insulin resistance is common in PCOS, and iron status matters after blood loss or restriction.
• Pelvic imaging: an ultrasound via GP referral assesses ovarian morphology and the uterine lining.
• Medications: a full prescription and supplement review identifies anything that raises prolactin or suppresses the axis.

Symptoms are also part of the picture: hot flushes or vaginal dryness (low oestrogen), nipple discharge or headaches (pituitary), and fatigue or temperature intolerance (thyroid).

Why it should not be left

Oestrogen supports bone, cardiovascular and brain health, so prolonged amenorrhoea is not only a fertility concern. Bone density is the main long-term consideration, and the longer oestrogen stays low, the more it matters.

See your GP promptly if you have vision changes, persistent headaches, nipple discharge, rapid unexplained weight loss, or signs of excess androgen such as a deepening voice. A missed period with a possible pregnancy also needs testing first.

How naturopathic care fits

Once the cause is identified, support is directed at the driver: restoring energy availability and nutrient status, supporting stress physiology and sleep, addressing insulin resistance in PCOS, and optimising recovery after hormonal contraception. It runs alongside, not instead of, medical investigation.

If your period has gone missing, book a consult and we will map out where the pathway is breaking down.