Clomifene (Clomid)

How does it work?

Clomid tablets contain the active ingredient clomifene citrate (previously spelt clomiphene in the UK). (NB. Clomifene is also available without a brand name, ie as the generic medicine.)

Clomifene works by causing an increase in the levels of hormones in the female body which control the development and release of an egg. These hormones are released from the pituitary gland in the brain and are known as follicle stimulating hormone (FSH) and luteinising hormone (LH). FSH stimulates the ovaries and LH causes the release of an egg from the ovaries (ovulation).

Oestrogen normally causes the brain to stop releasing FSH and LH following ovulation, as part of the normal menstrual cycle. It does this by acting on receptors in a part of the brain called the hypothalamus, which sends messages to the pituitary gland.

Clomifene works by blocking the oestrogen receptors in the hypothalamus. This stops oestrogen from acting on these receptors, and therefore stops the message being sent to the pituitary gland. This results in the release of more FSH and LH from the pituitary gland. The increase in these hormones increases the chances of egg development and ovulation.

Clomifene is used to stimulate ovulation in women whose infertility is due to problems with ovulation.

What is it used for?

  • Infertility in women caused by failure of ovulation


  • Women should have a pregnancy test to make sure they are not pregnant before each course of clomifene therapy.
  • Women should be evaluated for the presence of ovarian cysts before each course of treatment.
  • Inform your doctor if you experience weight gain, pelvic pain or abdominal pain, discomfort or swelling after taking this medicine.
  • Fertility treatment with this medicine carries an increased risk of multiple pregnancies, eg twins, triplets etc, and pregnancies outside the womb (ectopic pregnancy).Your doctor should discuss this with you before you start treatment.
  • This medicine should not be used for more than 6 cycles of therapy, as prolonged use may increase the risk of ovarian cancer.
  • This medicine may cause blurred vision or other visual symptoms during or shortly after taking the medicine. This may make it hazardous to drive or operate machinery, particularly under conditions of variable lighting. If you get visual symptoms you should tell your doctor. Your treatment will need to be stopped and you should have an eye examination.

Use with caution in

  • Polycystic ovary syndrome
  • Fibroids of the uterus
  • Endometriosis
  • History of seizures

Not to be used in

  • Pregnancy
  • Liver disease
  • History of decreased liver function
  • Certain types of cancer that are dependent on hormones for growth, eg endometrial cancer
  • Abnormal bleeding from the uterus of unknown cause
  • Ovarian cysts

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine should not be used in pregnancy. Women should have a pregnancy test to make sure they are not pregnant before each course of clomifene therapy. Seek medical advice from your doctor.
  • It is not known whether this medicine passes into breast milk. It may suppress the production of milk. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

  • Enlargement of the ovaries
  • Pain in the lower abdomen in the middle of the menstrual cycle (mittelschmerz)
  • Over stimulation of the ovaries causing production of many eggs
  • Hot flushes
  • Abdominal discomfort (swelling or bloating)
  • Nausea and vomiting
  • Breast discomfort
  • Visual disturbances
  • Headache
  • Spotting of blood between menstrual periods
  • Heavy or painful menstrual periods
  • Endometriosis
  • Dizziness
  • Nervous tension
  • Insomnia
  • Fatigue
  • Skin reactions such as rash and itch
  • Loss of contact with reality (psychosis)
  • Stroke (cerebrovascular accident)
  • Depression
  • Seizures (convulsions)

The side effects listed above may not include all of the side effects reported by the drug's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

There are no significant interactions reported with this medicine.

Other medicines containing the same active ingredient

Clomifene tablets are also available without a brand name, ie as the generic medicine.