From Harvard U: Toxicity of weight loss agents

http://www.ncbi.nlm.nih.gov/pubmed/22351299

J Med Toxicol. 2012 Feb 14. [Epub ahead of print]
Toxicity of Weight Loss Agents.
Yen M, Ewald MB.
Source
Children's Hospital Boston, Harvard Medical Toxicology Fellowship, 300 Longwood Ave, Ida C. Smith Building, Boston, MA, 02115, USA, May.Yen@childrens.harvard.edu.

Abstract
Introduction:
With the rise of the obesity epidemic in the United States over the last several decades and the medical complications seen with it, weight loss and dieting have become a national public health concern.

Discussion:
Because of their increased use and availability through internet sales, several different dieting agents were reviewed for potential toxicity. These included: syrup of ipecac, cathartics, human chorionic gonadotropin hormone, 2,4 Dinitrophenol, guar gum, phenylpropanolamine, ma huang/ ephedra, caffeine, clenbuterol, fenfluramine, sibutramine, thyroid hormone, orlistat and cannabinoid antagonists.

Conclusions:
With the internet making even banned products readily accessible, healthcare providers need to be aware of the potential toxicities of a wide range of weight loss agents. Our review covered topics we thought to be most historically significant as well as pertinent to the practice of medical toxicology today.