The product called 'Mega Slim' is suspected to be linked to serious health risks and this is not the first time its safety has been questioned.

This is a concern because the average consumer believes products sold OTC, particularly by a pharmacist, must be safe.

Mega Slim contains a compound called Citrus aurantium or bitter orange which is a flowering evergreen tree or plant, native to tropical Asia.

The dried outer peel of the fruit, without the white pulp layer, is used medicinally and the unripened fruit are a traditional flavouring in the liquor Curacao; the oil extracted from the peel of the fruit is used for a variety of ailments, mainly digestive.

Bitter orange has however a complex chemical makeup - the peel contains flavones, the alkaloids synephrine, octopamine, and N-methyltyramine and carotenoids.

Usually weight loss remedies contain between 100 - 200 mg of bitter orange extract in combination with other herbs - bitter orange extract commonly contains from 1.5 to 6% synephrine and while it is considered safe in the small amounts found in foods, bitter orange is not safe when used in high doses.

Synephrine and N-methyltyramine, can cause hypertension and cardiovascular toxicity and frequent contact with bitter orange peel or oil can also cause adverse skin reactions; large amounts of bitter orange peel ingested by children can cause intestinal colic, convulsions, and even death.

Bitter orange may also interact with medicines such as ulcer, anti-anxiety medication, blood pressure medications, cholesterol medications, allergy medication, fungal medications, HIV medications, sedation medication and anti-nausea medication and cause serious adverse effects.

Children and pregnant or breastfeeding women are advised not to use the herb as are people suffering from hypertension, tachyarrhythmia, or narrow-angle glaucoma.

As far back as 2002 scientists were issuing warnings regarding the use of bitter orange. Scientists at Georgetown University Medical Center in the U.S. said at the time in a review published in the September issue of Experimental Biology and Medicine, that people taking weight loss products that contain the herb Citrus aurantium may be doing more harm to their body than good.

According to the researchers there was no reliable scientific evidence to support the use of Citrus aurantium for losing weight and more importantly, high doses of the herb, which contains synephrine, may not be safe as it could cause hypertension, and also adversely interact with other drugs.

A complaint reportedly sent to the TGA has said that Mega Slim contains large amounts of bitter orange, which was linked to heart problems in a number of cases in Canada - two of which were fatal.

Mega Slim is distributed by the Victorian company Next Generation Supplements, which reportedly denies that there is any evidence to suggest it is dangerous to the health.

The TGA apparently warned the company in 2005 that it was breaking the law by making health claims for Mega Slim without having listed the product on the Australian Register of Therapeutic Goods, and told the company to cease making and supplying the product until a listing had been made but this happened again in 2005.

Experts say that unless advised by a doctor for a serious medical reason, fast weight loss can be harmful and programmes that promise quick weight loss should be viewed with caution. They say diet products and programmes which promise quick weight loss without effort ,are suspect and to achieve long-term or permanent weight loss a person must change how they eat and exercise and there are no miracle weight-loss products or plans - to lose weight, you have to reduce your intake of calories and increase your physical activity and be skeptical about exaggerated claims.

Weight-loss programs should encourage healthy behaviours which help you lose weight and which you can stick with every day and safe and effective weight-loss programmes should include healthy eating plans that reduce calories but do not forbid specific foods or food groups.

Depending on your starting weight, most experts recommend losing weight at a rate of 1/2 to at the most 2 kilos per week.

Scientists say the use of Citrus aurantium and other herbal weight loss products should not be considered safe simply because they are available OTC.