How contraceptive implants and injections work
NHS ChoicesMedical Reference
Contraceptive implants and injections steadily release the hormone progestogen into your bloodstream.
Progestogen is very similar to the natural hormone progesterone, which is released by a woman's ovaries during part of the menstrual cycle.
The continuous release of progestogen:
- stops you from releasing an egg every month (ovulation),
- thickens the mucus from the cervix, making it difficult for sperm to pass through to the womb and reach an unfertilised egg, and
- makes the lining of the womb thinner, so it is unable to support a fertilised egg.
- Uterus : The uterus (or womb) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.
- Ovaries: Ovaries are the pair of reproductive organs that produce eggs and sex hormones in women.