What is 19-norandrosterone and why Esther Onyema might be a victim of contaminated nutritional supplement

What is 19-norandrosterone and why Esther Onyema might be a victim of contaminated nutritional supplement


19-norandrosterone is a metabolite of nandrolone (19-nortestosterone) and Blandine (19-norandrostenedione) and it is one of the synthetic anabolic steroids banned in sports.

Nandrolone and other 19‐norsteroids have been banned to athletes for 30 years and are listed in section S1, anabolic agents in the World Anti‐Doping Agency list of prohibited substances and methods.

Investigation reveals that 19-norandrosterone has clinical potential in male fertility control, enhance surgery recovery and cancer related treatment but in the world of Sports, the substance is best known as a performance enhancing substance for increasing muscle strength and to speed up recovery.

According to the International Paralympic Committee, Esther Onyema violated an anti-doping rule violation (ADRV) and banned for four years after her urine sample which was taken on 28 January returned an adverse analytical finding for a prohibited substance called 19-norandrosterone.

Adverse analytical findings occur when the concentration of 19‐NA is greater than 2 ng/ml, with consideration being given to the estimated uncertainty of the measure

Though the victim  has not issued an official statement since the ban by the International Paralympics Committee.

But current reports regarding nandrolone-positive cases have been related to intake of some nandrolone-free nutritional supplements.

According to Barts Coumans in his article published in British Journal of Medicine

“Nutritional supplements can be a source of positive doping cases as some supplements contain prohibited substances without showing this on their label. This problem has existed for some time and has been extensively studied in the past 8 years”

Barts Coumans, who is head of Prevention at Doping Authority further analyzed the possibilities citing the example in tennis.

“For more than a decade, it has been known that nutritional supplements can be “contaminated” with doping substances, which means that the contents of the supplements are not identical to the list of ingredients on the label. Tennis has played a particular role in this debate because of the complexity of the cases of Bohdan Ulihrach and Greg Rusedski, who tested positive for nandrolone or nandrolone prohormones in 2002 and 2003, respectively”.

The tennis players were later exonerated after investigation reveals that they have taken contaminated nutritional supplements.

Most Sports Federations and international sport bodies has advised athletes against using nutritional supplements because ingredients of some nutritional supplements are not properly labelled.

Further research also reveals that the consumption of edible parts of a non-castrated pig, containing 19-norandrosterone can show a result in the excretion of 19-norandrosterone, hence why athletes are advised against the consumption of liver, kidneys and boar meats.

The Ministry of Sports in Nigeria and the agency in charge of Doping Control should carrying further investigations to know whether 19-norandrosterone found in Esther Onyema was intentional or as a result of consumption of contaminated nutritional supplements .


Mudashiru Shittu





Mudashiru Shittu

A Sport writer , reporter and a broadcaster with huge knowledge of Sporting Events in Africa and beyond .

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