Explain how the combined pill works as a method of contraception.

Edexcel GCSE Biology (1BI0) — 7.1 Hormonal coordination · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

The combined pill is one of the most widely used forms of hormonal contraception. It contains synthetic versions of oestrogen and progesterone and must be taken daily.

Model answer (4 marks)

The combined pill contains synthetic oestrogen and progesterone.
The high levels of these hormones inhibit the secretion of follicle‑stimulating hormone (FSH) by the pituitary gland.
Without FSH, ovarian follicles are not stimulated to mature, so eggs do not develop.
Because no mature egg is released, ovulation does not occur and fertilisation cannot take place, preventing pregnancy.

Examiner tips

Use the exact terms: oestrogen, progesterone, FSH, follicles, ovulation, fertilisation.
Show the causal chain: pill → hormone levels ↑ → FSH ↓ → follicles fail to mature → no ovulation → no fertilisation.
Keep the answer concise – 4 points, one sentence each.

Common mistakes

Confusing LH with FSH as the inhibited hormone.
Mentioning only one hormone (e.g., only progesterone) instead of both.
Failing to link the lack of ovulation to the prevention of fertilisation.

Mark scheme (4 marks)

The combined pill contains oestrogen and progesterone
The high levels of oestrogen and/or progesterone inhibit FSH secretion by the pituitary gland
Without FSH, follicles are not stimulated to mature / eggs do not develop
Ovulation does not occur, so fertilisation cannot take place / pregnancy is prevented

Key terms in this question

combined pill · contraception