Clomifene

Key points

• Clomifene is a selective oestrogen receptor modulator. It blocks oestrogen feedback in the hypothalamus, which signals the pituitary gland to release more follicle-stimulating hormone and luteinising hormone.
• It is used for anovulatory and oligo-ovulatory infertility in women who want to conceive.
• Ovarian hyperstimulation syndrome is a recognised risk and can worsen within 24 hours, so new abdominal bloating, pain or rapid weight change needs urgent medical review.

What Clomifene is used for

Clomifene is classed as an ovulation inducer and is prescribed where ovulation is absent or infrequent. It is used in Female Infertility for women who do not produce eggs but wish to become pregnant. The aim is to restore a cycle in which a mature follicle releases an egg.

How it works

The medicine binds to oestrogen receptors in the hypothalamus and blocks the usual negative feedback. The pituitary responds by increasing secretion of follicle-stimulating hormone and luteinising hormone, and these hormones drive the ovaries to mature follicles and release an egg. Onset is usually given as 5 to 10 days, and a treatment cycle runs for about 30 days.

Forms and brands

Clomifene comes as a tablet in 25mg, 50mg and 100mg strengths. Clomid is the brand name most often used for this ingredient. The medicine sits within Women’s Health, and it also appears under Hormone Therapy because of its effect on hormonal regulation. Pharmacy partners in India ship orders to Malaysia in discreet packaging.

Safety

Clomifene should not be used by anyone with liver disease, abnormal uterine bleeding or pregnancy. It is not for use in children. If pregnancy is suspected, the medicine should be stopped and a doctor told straight away. Anyone who is breastfeeding should confirm suitability with a qualified clinician or pharmacist before use. Oestrogens are a known interaction, so tell your prescriber about every medicine you take.

Nausea, headache and breast discomfort are common. Abdominal bloating, visual disturbances and ovarian hyperstimulation syndrome are more serious and need medical attention. Ovarian rupture and situations where oophorectomy is required are serious events requiring immediate medical attention. Vision changes should be monitored, and blurred vision means no driving or operating machinery until you know how the medicine affects you.

Clomifene raises the chance of a multiple pregnancy, such as twins or more. Long-term use may increase the risk of ovarian cancer, and it should not be used for more than about six cycles.

What the sources say

• Clomiphene is an FDA-approved selective oestrogen receptor modulator indicated to treat anovulatory or oligo-ovulatory infertility by inducing ovulation in patients who wish to conceive. (NCBI)
• It is a pregnancy category X medicine, contraindicated in pregnant women because the treatment offers no additional benefit in that group. (NCBI)
• Ovarian hyperstimulation syndrome has been reported with clomiphene therapy and can progress within 24 hours to become a medical emergency. (NCBI)
• Clomiphene increases the chance of a multiple pregnancy, such as twins or more. (MedlinePlus)

Further reading

• Clomiphene
• Clomid | healthdirect
• Clomiphene: MedlinePlus Drug Information
• Clomiphene - StatPearls - NCBI Bookshelf - NIH