Many weight loss and fat burning supplements taken by athletes contain a banned stimulant, a new study has found.

Researchers from the Harvard Medical School found the stimulant, oxilofrine, in 14 brands of supplements sold across the United States. These supplements are marketed for burning body fat.

Though the products listed the banned stimulant on their labels, the component was listed under another name, methylsynephrine.

Oxilofrine is a drug approved in some countries but it's banned in the United States. It's a stimulant of the amphetamine class that was developed originally to treat hypotension (low blood pressure) in people who do not respond to traditional treatment.

It has three other names - methylsynephrine, hydroxyephrine and oxyephrine. It's thought to increase adrenaline production which will result to higher endurance levels, increased focus, heart rate and oxygenation of the blood. These effects may be tempting for athletes to use especially when they need all the energy they could get during games.

If the component is used for a long time, it could result in tachycardia, a condition wherein the heart rate is very high, cardiac dysrhythmia or irregular heartbeat and hemorrhagic stroke, a fatal condition where a large vessel in the brain becomes too weak to hold blood causing leaks or may even burst, resulting in brain damage. It could also lead to hypertension in people taking the supplement with normal blood pressure.

"We found that not only did the supplements contain the banned drug, but that they were at extremely large dosages in some of the products," said lead researcher Dr. Pieter Cohen at Harvard Medical School in Boston.

Several athletes have been suspended after being tested positive for the banned ingredient. Many of them, however, claim that they are unaware that the supplements they are taking contain the said component.

"So it's been known since at least 2009 that dietary supplements may contain oxilofrine," said Cohen.

"This really raises the question, what is the FDA doing?" he added.

Experts raised concern over the loose regulation of dietary supplements in the country, since dietary supplements do not need to be proven effective before they are sold in the market.

The findings of the study also demonstrate the relative lack of safety measures in regulating dietary supplements as these are not only sold in market but also in online stores.

Photo: Laurie Beylier | Flickr