the drug allegedly found in Mykhailo Mudryk’s doping test explained

Chelsea Football Club revealed today that one of their players, Mykhailo Mudryk, has tested positive for a banned substance in a routine drug test.

The 23-year-old Ukranian winger said he has not knowingly taken any performance-enhancing drugs. It has been widely reported in the media that the drug Mudryk tested positive for is meldonium. The Guardian noted, though, that this has not been verified, having failed to receive comment from Mudryk’s agent.

Meldonium first became known to sports fans in 2016 when the former world number one tennis player Maria Sharapova tested positive for it. The drug became a World Anti-Doping Agency (Wada) prohibited substance on January 1 2016, and within a couple of months, hundreds of sports people had tested positive for it.

When Wada introduced the ban they did not realise the drug stayed in the body for weeks – perhaps months after use. Most drugs are cleared from the body within days. This meant many athletes tested positive in January, February and March, despite not using it after the ban.

The data from Wada shows 70 positive tests in 2022, so athletes are still using it even after the high-profile coverage.

Meldonium is not licensed for use in the UK, US or Europe but is in Russia and Latvia, where it was developed.

It is used clinically to help with heart problems, such as angina and chronic heart failure. Wada classes meldonium as a “metabolic modulator” – a type of drug that can speed up or slow down certain enzymes in the body, regulating things like energy production.

The drug reduces the use of fatty acids for energy production. It pushes the body to instead use glucose, which is a more efficient energy source when there is reduced oxygen either through heart disease or under intense exercise.

A review of published research showed that meldonium has a performance-enhancing effect in animals and human volunteers.

The shift to burning glucose is one effect. They also report that meldonium can reduce the production of lactic acid during exercise, which reduces fatigue and also improves recovery rates after exercise.

According to the drug’s inventor, Ivars Kalvins, the drug was used by Soviet soldiers when fighting in Afghanistan in the 1980s to improve their stamina.

There is evidence that brain activity is improved by increased oxidation, meaning decision-making and movement control will be preserved longer. Athletes can produce better performance for longer in these situations.

When a footballer tests positive there is often the comment that football is a skill sport so doping doesn’t help. Yes, football is a skill sport but it is also an endurance sport played over 90-plus minutes. The ability to produce high levels of skill when fatigued at the end of the game is clearly advantageous.

When a urine sample is collected from drug-testing athletes it is split into two portions and stored as A and B samples. If the A sample tests positive they then test the B to check they both contain the same drug. It has been reported but not verified that Mudryk’s B sample has not been tested yet.

There is a very low chance that these findings will be different. Issues only usually emerge if samples haven’t been stored properly.

Detecting meldonium in urine samples is not too difficult for a state-of-the-art Wada laboratory, equipped with technology such as liquid chromatography and mass spectrometry that can detect below one-tenth of the amount required to confirm doping.

Could it be from contaminated food?

Athletes who fail a drug test often defend themselves by saying the substance may have come from contamination from a supplement or food. In Mudryk’s case, it will be interesting to see details of when he was tested prior to this positive test.

Meldonium use needs several weeks to show health or fitness improvements. A negative test shortly before the positive helps the defence that is was not deliberate doping. If, as suggested in the Guardian, it was in August, then that wouldn’t help him with that defence.

One Russian study found meldonium in meat and cows milk. This opens the door to the possibility of consuming contaminated foods from some countries.

A German study gave volunteers meldonium-spiked milk and could detect it in their urine afterwards. Despite repeated ingestion of the milk, the maximum urinary meldonium concentration was well below the reporting threshold used to trigger a positive test in the laboratory.

According to Wada meldonium should not be reported at levels below 100 nanograms per millilitre (ng/ml) and with contamination they found less than 20ng/ml. This means it is unlikely an athlete would test positive from contaminated food.

There are no studies I can find that show contamination of supplements with meldonium, so this is also an unlikely defence.

According to UK Anti-Doping, athletes are ultimately responsible for any banned substance found in their system “regardless of how it got there or whether there was any intention to cheat”. A good defence will help reduce a likely ban, which could be up to four years for this offence.