These products tend to be a mix of herbs and vitamins and, often, stimulants such as caffeine, which can result in high blood pressure and heart palpitations. Herbs contain many chemicals, the presence and concentration of which can vary according to the source and the preparation. And in most of these weight-loss pills, ingredients are only individually tested for safety. They may interact with one another or with other medications.
Amazingly, two products we looked at contained both bitter orange and panax ginseng, which aren’t recommended to be taken together, due to an increased risk of fatal heart arrhythmias.
Hydroxycitric acid (HCA)
What is it? A derivative of the fruit from the plant Garcinia cambogia. May also be listed as brindleberry, Malabar tamarind, Garcinia quaesita, or hydroxycitric acid.
What they say it does Modifies metabolism, reduces fat synthesis and decreases appetite.
Can they prove it? Studies provide contradictory evidence. Some show some positive results, while others show no difference between the group taking HCA and the placebo. More comprehensive studies are needed.
Side effects and interactions None known. It appears to be safe over the short term in the doses studied.
Products: Naturopathica FatBlaster Max, Supprexxa Metabolism Formula.
What is it? An extract of the Seville orange, it also known as Citrus aurantium. Used in place of ephedra as it contains similar compounds.
What they say it does Increases metabolism and fat burning while decreasing appetite.
Can they prove it? Limited promising evidence; more research is needed on its safety and effectiveness.
Side effects and interactions Has been linked with fainting, heart attack and stroke. It is advised that you avoid bitter orange if you have a heart condition or are taking other medications.
Products: Rapid Burn Dual Action Weight-loss System, FatBlaster and FatBlaster Max, Hershel-Beck Laboratories Xantrax.
What is it? Capsaicin from hot peppers.
What they say it does Increases metabolic rate and reduces appetite.
Can they prove it? Studies on capsaicin are interesting but mixed – one shows that having a spicy entrée can reduce your total food intake over the whole meal.
Side effects and interactions Short term burning pain.
Products: Supprexxa Metabolism Formula.
Green coffee extract
What is it? An extract of raw coffee beans – it is believed that chlorogenic acid is the active ingredient.
What they say it does Increases metabolism and glucose control.
Can they prove it? There are some positive results from studies. However, the quality of the studies is poor, so more rigorous trials are needed.
Side effects and interactions None known, however the product safety hasn’t been confirmed in a large analysis. Has the potential to increase heart rate and blood pressure.
Products: Hydroxycut Advanced, Xantrax, FatBlaster Max.
Green tea extract
What is it? The catechins extracted from green tea.
What they say it does Reduces fat synthesis and absoption and increases metabolism.
Can they prove it? Conflicting results. Some studies suggest it needs to be taken with caffeine to be effective.
Side effects and interactions? Deemed safe. when formulated and taken appropriately, There’s some concern that green tea extracts may cause liver toxicity, especially if taken on an empty stomach.
Products: Xantrax, FatBlaster, FatBlaster Max, Rapid Burn.
What is it? Derived from the powdered shells of crustaceans.
What they say it does Binds to dietary fat to stop absorption.
Can they prove it? Studies show varying results, with only minor weight loss shown.
Side effects and interactions If it does work, there could be malabsorption of nutrients and loose, oily stools.
Products: Rapid Burn.
What is it? Chromium is an essential trace element commonly used in the form of chromium picolinate.
What they say it does Enhances insulin sensitivity and fat burning. May increase lean body mass.
Can they prove it? Experts agree there’s insufficient evidence to recommend it as a weight-loss aid.
Side effects and interactions No studies have reported side effects. However, it may cause DNA damage in high doses.
Products: Hydroxycut Advanced, Optislim Max, FatBlaster, FatBlaster Max, Xenadrine Ultra, Rapid Burn, Supprexxa Metabolism Formula.
In the last six months, Australia has seen two recalls that bring into question the regulation around listed weight-loss products.
In October 2010, we saw weight-loss chocolate bars pulled from sale as they contained an unlisted ingredient, the prescription drug, sibutramine. Sibutramine, previously a leading prescription weight-loss medicine, was withdrawn from the Australian market after being associated with cardiac events such as non-fatal heart attack and stroke.
In another worrying event, the heavily advertised Latin Seed was withdrawn for containing the poisonous yellow oleander, instead of candle nut as claimed on the label. It can cause a variety of symptoms from diarrhoea to heart damage.
While these events are unusual, the fact that they do happen makes it difficult to see how the TGA can consider these products “low risk”.