Another (Number) One: Iga Swiatek's Positive Test Explained

On this festive Thanksgiving day, tennis decided that we would all have seconds.

Three months after announcing the positive test of Jannik Sinner, the man who spent the majority of 2024 ranked No. 1 in singles this year, the International Tennis Integrity Agency (ITIA) announced Thanksgiving morning that the woman who spent most of this year ranked No. 1 in singles, Iga Swiatek, had also tested positive for a banned substance.

Swiatek, the ITIA announced, tested positive for trimetazidine (TMZ), a medication used to treat heart conditions, in a urine test before the Cincinnati tournament this past August. Swiatek argued, successfully, that she had ingested the substance because of contaminated melatonin pills, and received a verdict of “No Significant Fault or Negligence.”

Like Sinner’s ban, Swiatek’s was announced as a fait accompli rather than the typical pattern of announcing a provisional suspension pending adjudication: in its announcement today, the ITIA announced that Swiatek had already served a silent provisional ban earlier this year; the penalty announced today was a one-month ban that includes time already served silently, so the remaining days on Swiatek’s ban will run out on December 4th.

These cases are always complicated, and I think the best first step toward grasping and understanding what happened is to lay out a timeline of events in Swiatek’s recent months, merging both what we knew before and what we didn’t know until today.

An Amended Timeline of Iga Swiatek’s 2024 Season

This is a timeline made by synthesizing information which was already public about Swiatek’s season and new information that was attested in the ITIA’s 12-page decision about the case.

June 8th:

Top-ranked Iga Swiatek wins her fourth French Open title at Roland Garros, routing Jasmine Paolini 6-2, 6-1 in the final, her third straight tournament win following triumphs in Madrid and Rome the month before.

July 6th:

Swiatek’s 21-match win streak ends in the third round of Wimbledon to Yulia Putintseva.

August 1st and 2nd:

Swiatek, heavy favorite to win gold at the Olympic tennis event held at Roland Garros, loses in the semifinals to Zheng Qinwen. She comes back a day later and beats Anna-Karolina Schmiedlova in the bronze medal match. After both of those matches, Swiatek gives samples for anti-doping tests, both of which come back negative.

August 11th:

4 p.m.

A few days after arriving to the event, Swiatek holds a pre-tournament press conference at the Cincinnati Open.

August 12th:

~2-3 a.m.

Unable to fall asleep in her hotel room near the Cincinnati Open, Swiatek takes 2-3 tablets of melatonin, a substance which she said had been recommended to her by a doctor with expertise in sports medicine.

“Melatonin is necessary for me because all my travelling, jetlag and work-related stress mean that sometimes without it I couldn’t fall asleep and I would be having trouble sleeping,” Swiatek later said.

~6-8 a.m.:

Swiatek is awoken by anti-doping testers, and provides an early morning, out-of-competition urine test.

When filling out her doping control form that morning, Swiatek lists fourteen supplements and medications that she’s taking, but does not list the melatonin. Swiatek later explains that she “forgot to declare her use of the Product because it was not listed on her list of medications and supplements from which she copies information onto Doping Control Forms and she was tired, having only slept for a few hours between ingesting tablets of the Product and providing the sample.”

August 14th:

After a first round bye, Swiatek survives a patchy second round match in Cincinnati against Varvara Gracheva, winning 6-0, 6-7(8), 6-2.

August 18th:

Swiatek loses in the Cincinnati semifinals to Aryna Sabalenka.

August 23rd:

A day after he won the Cincinnati Open men’s singles title, the ITIA announces that ATP No. 1 Jannik Sinner has received a verdict of “No Fault or Negligence” for his positive test for clostebol. Sinner had continued playing with no one aware of his positive test, for which he had his provisional ban overturned. This will be the first of two times this season that a No. 1 player is embroiled in a controversy around a positive test for a banned substance.

August 27th:

Swiatek takes an anti-doping test after her first round win at the U.S. Open over Kamilla Rakhimova; this test later comes back clean.

September 4th:

Swiatek loses in the U.S. Open quarterfinals to Jessica Pegula.

September 12th:

The ITIA notifies Swiatek that her urine sample from before the Cincinnati tournament a month earlier tested positive for trimetazidine, at the low concentration of 50 picograms per milliliter. She is placed under a “mandatory provisional suspension,” effective immediately.

September 13th:

Swiatek withdraws from the WTA tournament in Seoul a few days before it is set to begin, providing the below explanation:

“My physical condition has not yet returned to normal since the US Open. I cannot go to Seoul. Please understand that I have no choice but to change my schedule. I definitely want to visit Seoul next year and play a great match in front of Korean fans.”

Swiatek was one of many top players to withdraw from the Seoul tournament.

September 14th:

Swiatek responded to the pre-charge notice, denying the charge and requesting that her B sample be analyzed.

September 19th:

Swiatek’s B sample also comes back positive for trimetazidine.

September 20th:

Swiatek announces that she is withdrawing from the China Open, where she was defending champion, citing “personal matters” and not acknowledging the unfolding case against her.

“Due to personal matters, I’m forced to withdraw from the China Open in Beijing. I’m very sorry as I had an amazing time playing and winning this tournament last year and was really looking forward to being back there. I know that the fans will experience great tennis there and I’m sorry I won’t be a part of it this time.”

September 22nd:

Within the 10-day deadline, Swiatek files an application to lift her provisional suspension, saying she had not deliberately used trimetazidine but saying that she had not yet been able to identify the source of unintentional ingestion.

September 25th:

The ITIA is unimpressed by Swiatek’s lack of explanation and says that she has not met the grounds to overturn her provisional ban.

September 26th:

Late the next evening, Swiatek replies that she commissioned experts to analyze various products she had been using, and that the results showed her Polish-made melatonin product (LEK-AM Melatonina) was contaminated with trimetazidine.

“Everyone got together to help me,” Swiatek later said of the effort to find the source of the contaminant. “They went all out to locate the source and I am forever grateful for that.”

The ITIA agrees to test the product at a lab in Salt Lake City to verify Swiatek’s claim of contamination. The ITIA is unsuccessful in obtaining its own container of sealed melatonin from the same batch—the ITIA later says that the manufacturer, LEK-AM, was uncooperative and unresponsive to its requests, both by telephone and email—so the lab tests both Swiatek’s opened, partially used container and a sealed container which was provided by Swiatek herself.

October 4th:

This was a very busy day for Iga Swiatek!

Morning:

Swiatek announces that she has parted with her longtime coach, Tomasz Wiktorowski, which you can read more about here from a post in the first week of Bounces’ existence:

Iga Swiatek Makes a Change at the Top

Simultaneously to the news of splitting with Wiktorowski, Swiatek announces that she was also withdrawing from the Wuhan Open, which was beginning a day later. Again, Swiatek did not mention the provisional ban she was serving when explaining her decision, instead citing the change in her coaching team.

“After an important change in my sports team, I decided to withdraw from the tournament in Wuhan. I’m really sorry for fans in China and those who wait to see me play, but I hope you understand that I need some time.”

Some time later that day:

The Salt Lake City lab confirms the presence of trimetazidine in both the open and sealed melatonin containers. They were able to “rule out potential manipulation” and said that the amount of trimetazidine in the supplement “was consistent with the estimated concentrations of TMZ found in the Player’s urine sample, based on the Player’s asserted ingestion.”

Evening:

The chair of the ITIA’s independent tribunal issues a decision lifting Swiatek’s provisional suspension, but tells Swiatek that it will “continue to more fully investigate the facts in order to assess the merits of the case.”

This investigation ultimately finds nothing to undermine Swiatek’s account: “No other evidence, including from the ITIA’s investigations and two detailed interviews with the Player, undermine the evidence provided to demonstrate source.”

October 17:

Swiatek that she has hired Wim Fissette, a prominent Belgian coach who had most recently worked with Naomi Osaka, as her new coach.

October 21:

Swiatek’s run of 50 straight weeks at the No. 1 ranking ends, passed in the rankings by Aryna Sabalenka, who had just won the Wuhan Open a week earlier. Though Sabalenka had been surging, the timing of this transition was somewhat unexpected, and occurred because of penalties assessed to each player for not playing enough tournaments.

Once it became public, Swiatek blamed her inability to defend the No. 1 ranking on the provisional ban:

“Unable to play the tournaments in Asia or defend my ranking, clearly it’s a consequence of this situation, but not the most important one for me. What mattered most for me was to prove my innocence.”

November 3:

Swiatek returns to competition at the WTA Finals in Riyadh, where she is defending champion, winning in three sets against Barbora Krejcikova. Swiatek loses her next round-robin match to Coco Gauff but wins the last of her three round-robin matches over Daria Kasatkina. This ends her season, as her 2-1 record is not enough to advance to the semifinals.

November 19th:

Swiatek plays her final matches of the 2024 season in the Billie Jean King Cup semifinal clash between Italy and Poland. Swiatek wins in singles over Jasmine Paolini but loses the doubles (alongside Katarzyna Kawa) to Paolini and Sara Errani.

November 28th:

The ITIA announces Swiatek’s positive test and her suspension for just one month, on the very low end of the scale for “No Significant Fault or Negligence” verdict but more than would be assessed for a “No Fault or Negligence” verdict. Because Swiatek only tested positive in an out-of-competition test, the positive test does not invalidate any of her results¹.

Swiatek also posts a long explanation video onto her Instagram page, in Polish but subtitled in English, which you can watch below.

Later on that same day, this post is published on Bounces, an unexpected course on my Thanksgiving.

December 4:

Swiatek’s ban will expire at midnight, weeks before her scheduled return to competition at the 2025 United Cup alongside Polish teammate Hubert Hurkacz.

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This post continues below with analysis of trimetazidine, scrutiny of preferential results for top players in the anti-doping system, erosion of trust caused by silent bans, and where Swiatek goes from here.

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