Micronised Progesterone

Micronised progesterone is a progesterone medicine used to support the uterine lining in selected fertility and hormone therapy plans.

Micronised means the progesterone particles are made very small to help the medicine be used by the body. It is chemically similar to the progesterone produced by the ovaries.

Progesterone changes the lining of the uterus after oestrogen has acted on it. The route, timing, and duration depend on the treatment plan. It may be prescribed by mouth or placed in the vagina, and those routes are not automatically interchangeable.

In assisted reproduction, progesterone may support the uterine lining around embryo transfer, including frozen embryo transfer. In menopause care, it may be combined with oestrogen for people who have a uterus, helping protect the lining from excessive stimulation.

Read more about [Embryo Transfer](/treatments/fertility-and-assisted-reproduction/embryo-transfer/), [Frozen Embryo Transfer](/treatments/fertility-and-assisted-reproduction/frozen-embryo-transfer/), or [Hormone Replacement Therapy](/treatments/menopause-and-hormone-therapy/hormone-replacement-therapy/).

A clinician may choose a different progesterone preparation, a synthetic progestogen, or another route depending on the goal, medical history, availability, and tolerance. In fertility treatment, the wider plan may also include a different cycle protocol. Do not substitute a product or change the route without confirmation.

Use micronised progesterone on the prescribed days and follow the stated route. In fertility care, timing can be linked to ovulation, a cycle schedule, or embryo transfer, so ask what to do if a dose is late or missed. In hormone therapy, bleeding may change during the first part of treatment and should be discussed if it is heavy, persistent, or unexpected.

Because oral use can cause drowsiness or dizziness, find out whether your prescriber recommends taking it at bedtime. Tell your clinician about new severe headache, jaundice, unusual bleeding, or a possible pregnancy.

The length of treatment is set by its purpose. Fertility support may follow a defined cycle, while hormone therapy may continue with periodic review. Keep appointments so the indication, bleeding pattern, symptoms, and other medicines can be reassessed.

Progesterone is not appropriate for every person or every type of bleeding. Seek urgent medical help for chest pain, sudden breathlessness, one-sided weakness, or a painful swollen leg, and contact your clinician promptly for concerning bleeding.