So let’s talk about what supplements clearly have been shown not to work OR the evidence is so weak that we just can’t say.

  • Fish oil – >10 studies, nil effect
  • Guar gum – in a meta-analysis of 20 clinical trials, guar gum was not effective for weight loss and caused adverse events such as abdominal pain, flatulence, and diarrhoea
  • Chitosan was ineffective for weight loss,
  • Colostrum – >10 studies, nil effect
  • Red clover extract – >5 studies, nil effect
  • Conjugated linoleic acid, garcinia cambogia, nigella sativa, vitamin E, cocoa, coleus forskohliji, vitamin C; hibiscus, olive leaf extract, turmeric, chromium, ginseng, glucomannan, hydroxy citric acid, L-carnitine, psyllium, whey protein,, magnesium, chlorella, spirulina, garcinia cambogia, pyruvate supplements, St. John’s wort, and conjugated linoleic acid.- Evidence and safety data were unclear
  • Hoodia Gordonii, a dietary supplement derived from a desert plant in South Africa, is marketed and sold as an appetite suppressant. However, its efficacy and safety have not been established in clinical trials
  • Ephedra, or ma huang, is a herbal stimulant that was once used in weight-loss products. In 2004, the FDA banned ephedra because of possible adverse effects, including mood changes, hypertension, irregular heart rate, stroke, seizures and heart attacks.
    • Bitter orange/(Citrus aurantium)is a currently available herbal stimulant that is often called an “ephedra substitute” and is used in some weight-loss supplements. – , a botanical source of synephrine showed a non-dose related increase in heart rate and blood pressure;
  • Two compounded dietary supplements imported from Brazil, Emagrece Sim (also known as the Brazilian diet pill) and Herbathin dietary supplement, have been shown to contain prescription drugs, including amphetamines, benzodiazepines, and fluoxetine.

In fact, there are so many that don’t work, it would be quicker to say which do work.