uses JavaScript to provide the best possible experience for our content, but your browser has it disabled. Learn how to enable it here.


Posted April 8, 2016

Large Doses of Stimulant Methylsynephrine Found In Weight Loss Supplements

Amounts of methylsynephrine found in some supplements exceed prescription dosages, according to new study published in Drug Testing and Analysis. Methylsynephrine, sold as a prescription stimulant drug in some European countries, is not permitted to be sold as a dietary supplement ingredient or prescription drug in the U.S. However, a number of weight loss and sports supplements sold in the U.S. list methylsynephrine on their labels (the FDA recently issued warning letters to seven companies whose products were labeled as containing the drug).

In the new study, researchers confirmed that 14 of 27 supplements purchased in the U.S. and labeled as containing methylsynephrine contained the unlawful ingredient, and that, among these, 43% contained doses which met or exceeded prescription strength dosages.

In Europe, methylsynephrine (also called oxilofrine) is prescribed to increase blood pressure in doses up to 40 mg for adults. In children and adolescents, doses typically range from 8 to 24 mg. Amounts found in the supplements ranged from 0.0003 to 75 mg per individual serving, and up to as much as 250 mg per recommended maximum daily serving. Methylsynephrine increases the speed and force of heart muscle contraction, increases blood pressure, and can affect heart rate. Consumption of methylsynephrine in supplements has been associated with serious adverse events including nausea, vomiting, agitation, tachycardia, chest pain, and cardiac arrest. 

To read the complete study, which lists the products which were tested as well as the amounts of methylsynephrine found in each, use the link below.

See Related Warnings:

FDA Warns of Stimulant Methylsynephrine In Supplements

FDA Identifies More Products Listing Synthetic Amphetamine

Does Your Weight Loss or Sports Supplement Contain Synthetic Amphetamine?

FDA Warns Companies Selling Products Containing Picamilon

Study Finds Some Vinpocetine Supplements Contain No Vinpocetine

FDA Targets Weight Loss and Workout Supplements Listing Synthetic Stimulant DMBA

New Synthetic Stimulant Found in Supplements