Clomid and Athletes: Doping or Legit Fertility Treatment?

The Facts Behind Clomid Doping Allegations

Dumbbells with bottle of Clomid used for doping

Oliver Hamalainen / E+ / Getty Images

Every so often, a story breaks about an athlete testing positive for Clomid (clomiphene) use on a drug test. Football player Robert Mathis of the Indianapolis Colts was accused of doping with clomiphene in 2014 and was temporarily suspended from playing in the National Football League (NFL). Mathis reported that he was taking Clomid as a treatment for male infertility. Sprinter Jason Livermore and netball player Simone Forbes are other athletes who have tested positive for Clomid use during sport drug testing. 

Clomid, also known as clomiphene citrate, 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 increase their odds of having a child. Isn’t Clomid a female fertility drug, or can it help treat male infertility, too? Read on for answers to these questions and more.

Understanding Androgens and Estrogens

Clomid can be misused by athletes to boost sports performance and counter the side effects of anabolic steroid use. To understand how this works, it's important to have a bit of a background on androgens (like testosterone) and estrogens. (Note: the following explanation is from a cisnormative perspective and doesn't take trans athletes into account.)

Androgens are frequently thought of as the “male” hormones and estrogens as the “female” hormones. However, both kinds of hormones are produced in both sexes. 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. Together with exercise and good nutrition, men with naturally higher testosterone levels will have an easier time building muscle mass and strength. Testosterone also affects the following:

  • Male hair growth (like facial and chest hair)
  • Mood and energy levels
  • Sex drive

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 drug tests that look for evidence of androgen doping. Even weeks after taking synthetic androgens, trace amounts are detectable in urine tests.

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

Boosting Performance or Covering-up Doping

Taking testosterone directly is only one way to boost androgen levels; it's also possible to boost testosterone indirectly. That’s what Clomid does.

Men have estrogen and estrogen receptors, just less than women have. Clomid works by blocking estrogen receptors in the body. When estrogen receptors are blocked, the body doesn't detect the levels of estrogen circulating in the body as it normally would.

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: luteinizing hormone (LH) and follicle stimulating hormone (FSH).

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

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

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

Clomid 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. Low levels of testosterone can lead to major health problems, including bone loss, insulin resistance, elevated cholesterol, and anemia. Clomid may help the body restart production of this essential hormone.

Can Clomid Boost Sports Performance in Women?

This is an important question because female athletes—due to their significantly lower fat deposits compared to average women—are at risk for experiencing irregular or absent ovulation (amenorrhea). It’s not uncommon for female athletes to stop getting their periods or have very light, infrequent menstruation from too much exercise. Exercise-induced amenorrhea is one of the conditions Clomid is typically used to treat.

Clomid can increase testosterone blood levels in female athletes. That is why the World Anti-Doping Agency considers it a doping substance for all athletes, not just men. However, male athletes are exponentially more likely to use Clomid or anabolic steroids for performance enhancement than female athletes.

Clomid Hidden in Blackmarket Performance Products

Bodybuilders and athletes may be tempted to purchase products online that are advertised to boost performance. Some of these products may be listed as containing "all-natural" ingredients or claim to contain nothing specifically banned. However, some black market products contained undisclosed clomiphene citrate.

One should always exercise caution when purchasing supplements or drugs online that come from questionable sources. Unfortunately, claiming to have not known a product you took contained a banned substance won't get you out of trouble. 

Do Men Take Clomid for Infertility?

Although Clomid is primarily used to treat ovulation problems in women, in some cases, it can be used off-label to treat male infertility. However, according to the Food and Drug Administration (FDA), there have been "no adequate or well-controlled studies that demonstrate the effectiveness of Clomid in the treatment of male infertility.”

However, both in general medicine and fertility, off-label use of a variety of drugs is common. For example, metformin, which is approved as a diabetes drug, may be used in the treatment of recurrent miscarriage or irregular ovulation, specifically in women with PCOS. Lupron, which is also not approved by the FDA as a fertility drug, is commonly used during IVF treatment.

Clomid has been found to help male infertility in the following ways:

  • 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.
  • Boost sperm count and motility. One meta-analysis found that treatment with Clomid, compared to no treatment, increased sperm concentration by about 5% and improved motility by about 4%.
  • Fix hormonal balances. According to that same study, reproductive hormone levels also significantly improved with Clomid treatment, with FSH levels rising 4% overall and testosterone levels rising 54%.

However, Clomid is not the most common or even most successful method for the treatment of male infertility. Depending on the cause of your infertility, your doctor may suggest the following:

What If Male Athletes Need Fertility Treatment?

The problems begin when athletes fail to disclose to the proper authorities their medical needs, so athletes should check with the professional sports organization they play under before starting any medication on the prohibited list.

Exceptions may be made sometimes. If an athlete needs to take Clomid for medical reasons, he can apply for what is known as a therapeutic use exemption (TUE). This will allow the athlete to use the usually prohibited drug for a specified set of time. 

It's important to apply for this permission even if you will only be taking the drug for a short period of time. Clomid can linger in your system for up to four months. Play it safe and always apply for an exemption, no matter what prohibited drug you're using and how long (or short) treatment will be.

A Word From Verywell

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.

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Article Sources
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  1. World Anti-Doping Agency. World Anti-Doping Code: International Standard: Prohibited List 2021. Updated January 1, 2021.

  2. USADA. Substance profile: What athletes need to know about clomiphene. Published February 2, 2017.

  3. Urology Care Foundation. What is low testosterone?. 2021.

  4. Anawalt BD. Diagnosis and management of anabolic androgenic steroid use. J Clin Endocrinol Metab. 2019;104(7):2490-2500. doi:10.1210/jc.2018-01882

  5. Guddat S, Fußhöller G, Beuck S, et al. Synthesis, characterization, and detection of new oxandrolone metabolites as long-term markers in sports drug testing. Anal Bioanal Chem. 2013;405:8285-8294. doi:10.1007/s00216-013-7218-1

  6. Chua ME, Escusa KG, Luna S, Tapia LC, Dofitas B, Morales M. Revisiting oestrogen antagonists (clomiphene or tamoxifen) as medical empiric therapy for idiopathic male infertility: A meta-analysis. Andrology. 2013;1(5):749-57. doi:10.1111/j.2047-2927.2013.00107.x

  7. Ip EJ, Doroudgar S, lau B, Barnett MJ. Anabolic steroid users' misuse of non-traditional prescription drugs. Res Soc Admin Pharm. 2019;15(8):949-52. doi:10.1016/j.sapharm.2018.07.003

  8. Kurera I, Yang T, Bano J. Clomiphene citrate treatment in women with hypothalamic amenorrhea. Endocr Abstr. 2018;59:190. doi:10.1530/endoabs.59.P190

  9. U.S. Food & Drug Administration (FDA). CLOMID® (clomiphene citrate tablets USP). Updated October 2012.

  10. Urology Care Foundation. What is male infertility?. 2021.

  11. World Anti-Doping Agency. Therapeutic use exemptions. 2021.

  12. Miller GD, Moore C, Nair V, et al. Hypothalamic-pituitary-testicular axis effects and urinary detection following clomiphene administration in males. J Clin Endocrinol Metab. 2019;104(3):906-14. doi:10.1210/jc.2018-01159

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