Clomid and Athletes: Doping or Legit Fertility Treatment?

The Facts Behind Clomid Doping Allegations

Dumbbells with bottle of Clomid used for doping
Is Clomid a legit treatment for male infertility? Or are the male athletes who take Clomid just trying to get away with doping?. Oliver Hamalainen / E+ / Getty

Every so often, a story breaks in the news about an athlete failing a drug test due to Clomid use. Clomid, also known as clomiphene citrate, is most commonly known as a female fertility drug, but it can also be used by athletes for nefarious purposes.

Clomid is listed as a prohibited substance by the NFL, the International Olympic Committee, and the World Anti-Doping Agency. If Clomid use is discovered in a random drug test, the athlete can be penalized.

Why would an athlete take a fertility drug like Clomid?

Some athletes caught taking Clomid claim they were taking it to treat male infertility. They say they were just trying to have a child.

Could it be true that a man would take Clomid in order to treat male infertility? Isn’t Clomid a female fertility drug?

How Athletes Might Use Clomid to Boost Performance or Cover-up Doping

Before we talk about Clomid, we need to briefly talk about androgens (like testosterone) and estrogens.

Androgens are frequently thought of as the “male” hormones and estrogens as the “female” hormones. However, both kinds of hormones are produced in both genders. Men naturally have higher levels of androgens and lower levels of estrogens, and women have higher levels of estrogens and lower levels of androgens.

Testosterone, one of the primary androgen hormones, plays a big role in the development of muscle mass and strength.

It also affects sex drive, mood and energy levels, and male hair growth (like facial and chest hair).

Together with exercise and good nutrition, men with naturally higher testosterone levels will have an easier time building muscles mass and strength.

Athletes may attempt to boost performance by illegally taking synthetic testosterone, usually in pill form, or natural testosterone hormones, usually via injection.

Anabolic steroids, for example, are a form of synthetic testosterone.

Besides being dangerous and risky, taking additional androgens is considered cheating in the sports arena. Many sporting and doping organizations ban the use of androgen drugs and hormones.

Athletes are required to take unscheduled, random drugs tests that look for evidence of androgen doping. Even months after taking synthetic androgens, trace amounts are detectable in blood tests.

For athletes looking to enhance performance, the long-lasting evidence left by illicit androgen use makes it a risky choice.

Few smart athletes would dare to try it.

However, taking testosterone directly is only one way to boost androgen levels. It’s also possible to boost testosterone indirectly.

That’s what Clomid does.

Remember first that men have estrogen and estrogen receptors, just less than women have. Clomid works by blocking estrogen receptors in the body. Because the estrogen receptors are blocked, the circulating estrogen in the body isn’t detected normally.

This leads the hormone-producing glands to think estrogen levels are low (even though they aren't), and so the glands attempt to produce more estrogen. The body does this by boosting production of two other important reproductive hormones: LH and FSH.

What does this have to do with testosterone? Well, testosterone is produced by cells known as Leydig cells. They produce testosterone in response to LH. So higher levels of LH means higher levels of testosterone. 

This is how Clomid raises testosterone levels indirectly. The athlete isn’t directly taking additional testosterone, but tricking his body into producing more on its own.

Clomid isn’t the only drug that can be used this way. Others include chlorotrianisene (TACE), ethamoxytriphetol (MER-25), and tamoxifen (Nolvadex). Many of these drugs are prohibited by doping agencies as well.

Clomid may be taken by an athlete looking to boost performance by indirectly raising natural testosterone levels in the body, but it may also be used to counter the side effects of anabolic steroid use.

With anabolic steroid use, the body eventually reduces or stops producing testosterone on its own. Clomid may help the body restart its own production of natural testosterone. 

Do Men Take Clomid for Infertility? Isn’t Clomid Just for Women?

Clomid can be used to treat male infertility in some cases. Even though it’s primarily used to treat ovulation problems in women, fertility specialists do prescribe it for men as well.

As you read above, Clomid can help boost testosterone levels. One possible cause for poor semen health and low sperm counts can be low testosterone, and Clomid may be able to resolve this in specific cases.

Whenever Clomid and doping hit the news, media outlets like to point out that Clomid does not have FDA approval for male infertility treatment.

And this is true. Using Clomid to treat male infertility is considered to be off-label use. However, this isn’t something to get all excited about. Both in general medicine and fertility, off-label use -- of a variety drugs -- isn’t rare.

In women, for example, metformin may be used in the treatment of recurrent miscarriage or irregular ovulation, specifically in women with PCOS. But metformin is a diabetes drug and not FDA approved as a fertility drug.

Lupron is another drug not approved by the FDA as a fertility drug, but it is commonly used during IVF treatment.

What Are Male Professional Athletes Supposed to Do if They Need Male Fertility Treatments?

Athletes should check with the professional sports organization they play under before starting any medication on the prohibited list. There may be exceptions made.

The problems begin when athletes fail to disclose to the proper authorities their medical needs.

It’s also important to point out that Clomid is not the most common or even most successful method in the treatment of male infertility.

For example, it’s much more common for men to have abnormal sperm counts with normal testosterone levels. In most of these cases, the cause for abnormal sperm counts is unknown.

For men experiencing abnormal sperm counts for an unknown reason, research has not found Clomid to be a useful medication.

Can Clomid Boost Sports Performance in Women?

Both female and male athletes may abuse drugs to boost performance, and yet, we never hear of female athletes getting caught taking Clomid.

(Yes, I realize that the sports that make headlines with regards to doping are often male dominated, but the Olympics, for example, include both genders in a highly competitive arena.)

This is an important question because female athletes – due to their significantly lower fat deposits – are at risk for experiencing irregular or absent ovulation. It’s not uncommon for female athletes to stop getting their periods or have very light, infrequent menstruation. This is exactly what Clomid is meant to treat.

Here’s the good news: current research has found that Clomid does not boost testosterone blood levels in women. Therefore, Clomid shouldn’t be considered a doping substance for female athletes.

However, you should always check with your athletic association before starting any treatment.

Bottom Line for All Athletes Seeking Fertility Treatment

All athletes -- female and male – are responsible for the drugs and hormones they take, and they must know what medications are on the prohibited list of substances.

Especially when you’re dealing with hormones, you must confirm with both your doctor and the relevant athletic organizations that your treatment won’t lead to penalties or doping allegations.

As some athletes have painfully discovered, ignorance of the rules is no excuse.

More on the male side of infertility:


Chatterjee S1, Chowdhury RG, Khan B. “Medical management of male infertility.” J Indian Med Assoc. 2006 Feb;104(2):74, 76-7.

Handelsman DJ. “Indirect androgen doping by estrogen blockade in sports.” Br J Pharmacol. 2008 Jun;154(3):598-605. doi: 10.1038/bjp.2008.150. Epub 2008 Apr 21.

Handelsman DJ. “Clinical review: The rationale for banning human chorionic gonadotropin and estrogen blockers in sport.” J Clin Endocrinol Metab. 2006 May;91(5):1646-53. Epub 2006 Feb 14.

Whitten SJ1, Nangia AK, Kolettis PN. “Select patients with hypogonadotropic hypogonadism may respond to treatment with clomiphene citrate.” Fertil Steril. 2006 Dec;86(6):1664-8. Epub 2006 Sep 27.

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