Many botanical and “natural” weight loss supplements claim to be effective in stimulating or enhancing weight loss. But what do the experts have to say about these purportedly magic pills? The American Dietetic Association (ADA) weighed in on this topic in a recent research review. It appeared in a special supplement to the ADA’s flagship publication, the Journal of the American Dietetic Association.

“Although there are few examples of safety concerns related to products that are legal and on the market for this purpose [weight loss], there is also a paucity of evidence on safety for this intended use,” said the authors of the May 2005 article. “More information on the characterization, pharmacology, history of use and safety of such products is needed. Health professionals and consumers need to be aware that the adverse effects may outweigh the benefits of agents used for stimulating weight loss.”

In particular, the review singled out the following supplements:

  • ephedra (ma huang): adverse effects reported; sale prohibited in the United States since 2004
  • bitter orange: no evidence of efficacy; safety concerns have been raised
  • calcium: evidence of benefit equivocal and limited to small trials; no major concerns raised to date regarding adverse events
  • chitosan: little evidence of benefit; some adverse events (gastrointestinal symptoms) reported
  • chromium picolinate: little evidence of benefit; few or no adverse events reported
  • conjugated linoleic acid (CLA): little evidence of benefit

In conclusion, the report urged health professionals and consumers to stay abreast of news on weight loss supplements and encouraged more research on these products. The ADA says reliable information on this topic can be found online at the National Health Institute’s Office of Dietary Supplements website at