Evidence Files
Meldonium: How a Latvian Cardiac Drug Became the Most Famous Banned Substance in Sports
In January 2016, WADA added meldonium to its prohibited list. In March, Maria Sharapova announced she'd been taking it for ten years. Overnight, a Soviet-era Latvian cardiac drug became the most Googled pharmaceutical compound on the planet. But very few of those searches led to an honest answer about what it actually does.
Verdict
TRICK (weak evidence)
We searched PubMed and Cochrane Library for clinical evidence on meldonium. Studies exist — mostly from Latvia and Russia, frequently with manufacturer involvement. There is modest evidence for specific cardiac indications. The evidence base for most common uses and especially for athletic performance enhancement is weak and methodologically limited.
What it is and where it came from
Meldonium was developed in Soviet Latvia in the 1970s by chemist Ivars Kalviņš at the Institute of Organic Synthesis in Riga. The mechanism: it blocks an enzyme in the carnitine biosynthesis pathway, shifting cellular metabolism away from fatty acid oxidation toward glucose — theoretically more oxygen-efficient under ischemic conditions.
The drug is manufactured by Latvian company Grindeks and marketed as Mildronate. It's registered in Latvia and several post-Soviet countries for heart failure, angina, and myocardial infarction recovery. It's not approved in the EU as a whole, not in the US, not in most of Western Europe.
WADA banned it not because there was solid evidence it enhanced performance, but because preliminary data suggested it might — and because of the sheer number of Eastern European athletes testing positive for it. The ban came first; the performance evidence was assumed.
What the science actually says
- Cardiac applications — some RCTs show modest benefit in stable angina and heart failure; most conducted in Latvia and Russia, raising independence concerns
- Athletic performance — WADA banned it based on preliminary signals, not confirmed RCTs; no large independent trial has proven performance enhancement in healthy athletes
- Study geography problem — the manufacturer's home country produces the bulk of positive evidence; this is a significant bias concern in systematic reviews
- Mechanism plausibility — the biochemical mechanism is real and understood; whether this translates to clinically meaningful outcomes in the populations tested is less clear
- Post-ban research — a 2020 review found insufficient evidence to draw firm conclusions about performance effects; the ban may have been precautionary rather than evidence-based
Why athletes took it vs. why WADA banned it
Why athletes used it
Widely available in Eastern Europe. Marketed as improving endurance and recovery. Legal before 2016. Culturally normalized in post-Soviet sport medicine. Prescribed by team doctors with a cardiac-enhancement rationale.
Why WADA banned it
Preliminary signals in animal studies suggesting metabolic enhancement. Abnormally high prevalence among Eastern European athletes. Potential for performance benefit under the precautionary principle — not confirmed clinical evidence of doping effect.
Our Conclusion
Meldonium sits in an honest grey zone: there's real pharmacology here, some evidence for specific cardiac conditions, and a plausible mechanism for why athletes might have used it. But "plausible" and "proven" are not the same. The evidence for most of its claimed benefits — and especially for athletic enhancement — doesn't hold up under scrutiny. The Sharapova scandal made meldonium famous. The clinical evidence didn't follow.
This article is for informational purposes only and does not constitute medical advice. Trick or Treatment analyses the presence of clinical studies in open scientific databases — PubMed and Cochrane Library. The absence of studies in these databases does not automatically mean a drug is ineffective, but it does mean its effectiveness has not been confirmed by evidence-based medicine standards. Any treatment decisions should be made together with your doctor.