Health Canada's caution reiterates earlier missives in 2006 and 2005 reminding consumers about the "serious, possibly fatal" hazards of using Ephedra or ephedrine, "either alone or in combination with caffeine and other stimulants, for purposes of weight loss, body building or increased energy." Over-the-counter nasal decongestants are the only form in which Ephedra and ephedrine are authorized for use in Canada and should be used only as directed, for short periods of time, Health Canada said. The maximum allowable dosage for ephedrine is 8mg in a single dose or 32mg per day; for Ephedra 400mg in a single dose or 1,600mg per day. Ephedra or Ma Huang are common name for the plant Ephedra sinica, from which the active ingredient ephedrine is derived. It has been used in Traditional Chinese Medicine for thousands of years. Don't buy, and beware Health Canada was unavailable for comment about whether a specific incident had prompted it to issue its third Ephedra warning in four years, but NutraIngredients.com could find no evidence of recent adverse event reports. Nor is the size of the Canadian grey market for banned Ephedra-based products clear, but they are certainly available online. "Consumers are reminded to exercise caution if they choose to purchase Ephedra/ephedrine-containing products or health products over the internet," it warned. "International reports of serious adverse reactions have been associated with unauthorized products containing Ephedra/ephedrine in combination with other stimulants that were purchased online." Health Canada reminded retailers not to sell unauthorized products containing Ephedra or ephedrine and asked consumers to report any banned products they encountered. The Food and Drug Administration (FDA) issued a similar ban in the US in 2004 after a number of heart-related deaths and serious reactions occurred as a result of its misuse as a weight loss supplement and athletic aid. Ephedra is also banned in most European countries. Preparations and effects Health Canada said potential Ephedra side-effects include dizziness, headache, decreased appetite, anxiety, restlessness or nervousness, gastrointestinal distress, irregular or fast heart beat, insomnia, flushing, sweating, hypertension, stroke, seizures, psychosis and death. Ephedra goes by many names and can be listed on products as Ma Huang, Chinese Ephedra, Ma Huang extract, Ephedra, Ephedra sinica, Ephedra extract, Ephedra herb powder, Sida Cordifolia or epitonin, all of which indicate a source of ephedrine. With its particular concern about Ephedra being consumed in combination with other stimulants it warned typical caffeine sources in combination products included green tea, guarana, yerba mate, cola nut and yohimbe, as well as other stimulants such as bitter orange and its active ingredient, synephrine. "Use of products containing ephedrine is not recommended in people with heart problems, hypertension, thyroid disease, diabetes, enlarged prostate, anxiety and restlessness, glaucoma (serious eye disorder) and pheochromocytoma (serious gland disorder) because Ephedra/ephedrine aggravates these conditions," Health Canada warned. "Consumers should use Ephedra/ephedrine products only for the approved indication of nasal decongestion, and should not exceed the maximum allowable dosage described in the Ephedra and ephedrine/pseudoephedrine labelling standards, unless this has been recommended by and you are under the surveillance of a health care practitioner. These products should also be avoided during pregnancy and lactation." US ban The 2004 FDA ban was seen as a significant landmark in US food law as it demonstrated the 1994 Dietary Supplements and Health Education Act (DSHEA) was not - as critics were calling it - a laissez faire, toothless piece of legislation incapable of safely regulating the dietary supplements industry. Others argued the ban went too far and warning labels were a more appropriate measure, a debate that has played out in US courts since 2004 as companies have appealed against the FDA position. The latest came in May last year when the US Court of Appeals rejected Utah-based Nutraceutical Corporation's challenge to the ban on the grounds that FDA's determination of "unreasonable risk" was itself unreasonable and meant virtually all dietary supplement ingredients stood the risk of being banned. The court rejected the appeal without comment.