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Meet your hormones

Oestrogen, progesterone, LH, FSH and testosterone, minus the jargon.

Cycle basics5 min readDeep dive

Written by the Splash teamSources checked

On this page 7 sections
  1. Quick answer
  2. The brain bosses: GnRH, FSH and LH
  3. Oestrogen: the builder
  4. Progesterone: the steadier
  5. Testosterone: yes, you have some too
  6. Can a test tell me my hormone levels?
  7. Sources

Quick answer

  • The brain sends GnRH, FSH and LH to direct the ovaries.
  • Oestrogen builds; progesterone steadies things after ovulation.
  • The LH surge triggers ovulation and is what LH tests measure.
  • Everyone with ovaries makes some testosterone.
  • One hormone test is only a snapshot, so timing and symptoms matter.

Hormones are chemical messengers. In your cycle, a handful pass notes back and forth between your brain and your ovaries. Here is who does what.

The brain bosses: GnRH, FSH and LH

The hypothalamus releases gnRH in pulses, which tells the pituitary gland to release two hormones:

  • FSH (FSH): rises at the start of the cycle and tells follicles in the ovary to grow.
  • LH (LH): stays fairly low, then surges just before ovulation and triggers the egg's release. This surge is what ovulation test strips pick up.

Oestrogen: the builder

Oestrogen (spelled estrogen in the US) is made mainly by growing follicles. It thickens the womb lining and makes cervical mucus slippery. It also supports bones, skin, and the heart and blood vessels. It peaks just before ovulation, dips, then has a smaller second rise in the luteal phase.

Progesterone: the steadier

Progesterone is made by the corpus luteum after ovulation. It keeps the womb lining stable, thickens cervical mucus, and raises your resting temperature a little. When it falls at the end of the cycle, your period starts. Its rise is why temperature tracking can confirm ovulation has already happened.

Testosterone: yes, you have some too

Ovaries and adrenal glands make small amounts of testosterone. It plays a part in libido, muscle and bone, and your body also converts it into oestrogen. Higher-than-usual levels, such as in PCOS (which the NHS now also calls PMOS), can show up as acne, extra hair growth or irregular periods.

  1. Period

    Oestrogen and progesterone at their lowest; FSH starting to rise.

  2. Follicular

    Oestrogen climbing steadily.

  3. Ovulation

    Oestrogen peaks and LH surges.

  4. Luteal

    Progesterone high, oestrogen moderate, then both fall before your period.

Can a test tell me my hormone levels?

It can, but one result is a snapshot of a moving target. Your levels change through the cycle and even through the day, so the timing of a blood test matters and results are only meaningful alongside your symptoms and cycle dates. NICE advises against routine hormone testing for heavy periods, for example. Home hormone kits and "hormone panels" sold online are not a shortcut to a diagnosis.

MythOestrogen is "good" and progesterone is "bad", or the other way round.
Fact

Each hormone has its own jobs and you need both. Problems tend to come from hormones being out of step with each other or with what the body needs, not from one hormone being the villain.

Quick quizWhich hormone do ovulation (LH) tests detect?
  1. Progesterone
  2. Luteinising hormone
  3. Testosterone
Show the answer

B. Luteinising hormone

LH surges before ovulation (a positive result usually means ovulation within about 36 hours), and the strips detect it in your wee.

Sources

  1. Cleveland Clinic: Estrogen
  2. Cleveland Clinic: Progesterone
  3. Cleveland Clinic: Ovulation
  4. Cleveland Clinic: Follicular phase
  5. NHS: Polyendocrine metabolic ovarian syndrome (PMOS, formerly PCOS)
  6. NICE NG88: Heavy menstrual bleeding: assessment and management

Written by the Splash teamSources checked

This is general information, not medical advice. Splash can’t diagnose. If you’re worried, talk to a GP, pharmacist or sexual health clinic. In an emergency call 999 (UK) or 911 (US). How we write and check articles.

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