You’ve probably heard of Clomid? One of the most common drugs used in fertility medicine. It’s been around since the 1960s, so we’ve had a lot of experience with this medication. We use it to help women with Polycystic Ovarian Syndrome (PCOS) ovulate and less commonly it’s used to improve men’s sperm counts.

It’s time to move over though, Clomid. There’s a new kid on the block called Letrozole. When new drugs arrive on the fertility medicine scene we get a little excited because it doesn’t happen that often, especially when it’s an improvement on existing options. Both of these drugs are used with the aim to cause egg release (ovulation) and hence, pregnancy.

Many Australian fertility specialists are now using Letrazole as the drug of choice over Clomid. It’s not to say that Clomid doesn’t work; it’s made many babies and for that we are grateful. It’s just that now there is something better, with the scientific evidence to back it up.

In 2014, a randomized study showed that letrazole, was associated with higher live birth and ovulation rates among infertile women with PCOS, when compared with clomid (1).

In 2015, a Cochrane review concluded that “Letrazole is superior for the treatment of subfertility in women with PCOS who have had no previous treatment for ovulation induction or are resistant to clomiphene citrate”. (2)

In Australia, Letrazole is used “off label” which means it’s not approved by the Therapeutics Goods Association (TGA) for use in women as a fertility medication. It’s approved to treat women with breast cancer. Yet, there are many drugs that are used off label.

Legally, there are no issues with your doctor prescribing off label medications (3). However, it’s the responsibility of your doctor to be able to justify the reasons they are prescribing that medication. So please don’t fret if you read on the product information sheet “Do not take this medicine if you are still having periods”.

I also prefer to use Letrazole as I also see less side effects when compared to Clomiphene. With clomiphene, the most common side effects I see in my patients are mood changes, hot flushes and what patients often describe as ‘feeling off” . This tends to be more common in the first cycle. Patients don’t complain as much when taking Letrazole.

It’s important for doctors to ask their patients “ How do you feel on the medication ?” We can’t rely solely on studies to inform us on how patients may tolerate treatments.

Both of these drugs have similar prescribing patterns in that they are given for 5 -7 days at the beginning of your cycle. A reminder that all hormones should be taken at the same time every day.

You’ll read a lot about these medications online, in forums etc. Ask your doctor to provide you with links to the current, up-to-date evidence to avoid any confusion and to get the right information. It’s good to keep us on our toes !

Wishing you great health,

Dr. Natasha Andreadis



  1. Letrazole versus Clomiphene for Infertility in the Polycystic Ovarian Syndrome. Negro, R et al. N Engl J Med 371; 2 July 10, 2014


  1. Aromatase inhibitors for subfertile women with polycystic ovary syndrome: summary of a Cochrane review. Sebastian Franik et al. Fertility Sterility 2015; 103 : 353 -5.


  1. Off-label prescribing. Editorial Volume 36 : Number 6 : December 2013