Trimetazidine (IUPAC: 1-(2,3,4-trimethoxybenzyl)piperazine) is a drug sold under many brand names for angina pectoris (chest pain associated with impaired blood flow to the heart).

[citation needed] However, a 2020 placebo-controlled, randomized trial in over 6000 patients who had recently had a percutaneous coronary intervention or heart surgery found that adding trimetazidine to typical anti-anginal therapies alone led to no significant difference in cardiac death, hospital admission for a cardiac event, recurrence or persistence of angina, or the need for repeat coronary angiography.

The United States Anti-Doping Agency (USADA) contacted WADA in 2020 (before the positive TMZ cases arose) and 2023 with respect to allegations (from an unspecified source) of doping cover-ups within Chinese swimming.

[16] Several media outlets reported on Wednesday that the issue was over a December 2021 test for trimetazidine by the Russian Olympic Committee's Kamila Valieva,[17][18] whose result was released on February 11.

[19] Valieva was cleared by the Russian Anti-Doping Agency (RUSADA) on February 9, a day after positive results of a test held in December 2021 were released.

Scott Powers, a physiologist at the University of Florida who studies the effects of exercise on the heart explained how trimetazidine was included in WADA list.

Faber has pointed out for years the necessity to establish thresholds for trimetazidine detected so as to avoid any inadvertent positive doping cases.

[25][12] On the efficacy of the drug on figure skating and Valieva in particular, heart expert Benjamin J. Levine, a professor of exercise science at the University of Texas Southwestern Medical School, said "The chance that trimetazidine would improve her performance, in my opinion, is zero.

[29] Iga Swiatek, at the time the top-ranked women's tennis player, tested positive for trimetazidine in September 2024 and was provisionally suspended for one month, missing several tournaments, after accepting a ruling of "No Significant Fault or Negligence," because she consumed it through a contaminated melatonin supplement.

[32] A 2013 international multicentre retrospective cohort study has indeed shown that in patients with heart failure of different etiologies the addition of trimetazidine on conventional optimal therapy can improve mortality and morbidity.

Trimetazidine works by inhibiting a specific enzyme called long-chain 3-ketoacyl-CoA thiolase, which is involved in the beta-oxidation process of fatty acids.

[34] Therefore, by enhancing glucose oxidation and reducing the reliance on fatty acid metabolism, trimetazidine helps optimize cellular energy production in conditions where oxygen supply is limited.

By ensuring adequate ATP levels, trimetazidine helps to maintain cellular homeostasis, or the balance of different ions and molecules within the cell.