[biot]

This part is also notable:

  In October 2000, the FDA warned [Karl Loren] that the long list
  of therapeutic claims he was making for these products made them
  drugs would be illegal to market without FDA approval. The letter
  stated that the FDA had seen no evidence that the products were
  safe and effective for their intended uses.

Absence of evidence that it's safe doesn't necessarily imply that it's unsafe. However, one should be cautious until peer-reviewed research on the long-term effects have been studied.