What Is Clomid And How Does It Work? Fertility Medication's Side Effects And Success Rate

It's commonly used for women with PCOS.

Women who suffer fertility problems will be offered different treatments depending on what’s causing the problem.

However one of the most common fertility medicines on the NHS is clomifene, a medicine that encourages the monthly release of an egg in women who don’t ovulate regularly or who can’t at all.

Clomifene (which is often referred to by the brand name Clomid) is usually prescribed to women who have polycystic ovary syndrome (PCOS).

Using the fertility drug can also result in a greater chance of having twins.

We spoke to Dr Geeta Nargund, medical director of CREATE Fertility and Dr Kim Clugston, fertility expert at DuoFertility to find out more about the fertility treatment option.

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How common is it for women to use clomid?

Dr Nargund told HuffPost UK: “It is used in women with PCOS to induce ovulation and in those where ovulation is irregular to regularise ovulation.

“It is commonly used as an effective first-line treatment for ovulation induction and is widely available on NHS.

“However, it should be prescribed by a fertility specialist (not by a GP) after pre-treatment counselling and tests in order to ensure that the dosage is tailored to achieve successful outcome and avoid risks.”

The most recent NICE guidelines suggest that Clomid should not be given to women with unexplained infertility as there is no evidence to suggest it increases pregnancy rates.

How does it work?

Women take one oral tablet daily (typically 50mg) for five consecutive days at the beginning of their cycle.

“Clomid is an anti-oestrogen,” explained Dr Nargund. “It stimulates the pituitary gland to release hormones needed to stimulate ovulation.”

Dr Clugston said it tricks the body into thinking that there is not enough oestrogen which sends a signal to the pituitary gland to secrete more follicle-stimulating hormone (FSH).

“This promotes the growth of follicles and the development of a usually a single dominant follicle that contains a mature egg which is released at ovulation,” she said.”

Are there any side effects of clomid?

Clomid is generally “very well tolerated” explained Nargund.

“Mood swings are the most common side effect,” she said. “Visual disturbances and hot flushes are rare side effects. Other rare side effects include pelvic discomfort, breast tenderness and nausea.”

Ovarian Hyperstimulation Syndrome (OHSS) is a rare side effect that can result from an “over-response” to Clomid - this is a “rare but serious condition”.

You should seek medical advice if these symptoms persist or become severe.

What’s the success rate?

“The main aim of Clomid is to restore ovulation and it will do so in around 70-80% of women who take it,” said Dr Clugston. “Once ovulating, these women have a chance of pregnancy, which is roughly 20% per cycle.

“Clomid is generally well tolerated by most women but it can have some negative effects on cervical mucus and on the endometrium, which may have an impact success rates. However, for women who are not ovulating naturally the benefit of ovulating outweighs these changes.”

Women should talk to their GP regarding fertility treatment options. For more information on Clomid, visit the NHS Choices website.

Before You Go

10 Things You May Not Know About Your Fertility