as summarized from Health Canada.ca

An increasing number of Canadians are using health products for weight loss, including prescription drugs and natural health products (NHPs). These products may provide benefits when used properly as part of a weight management program. However, misuse of these products can pose serious risks to your health.

The number of Canadians who are overweight or obese has increased dramatically over the past 25 years. Being overweight or obese increases your risk of developing a wide range of serious diseases and conditions, including high blood pressure, coronary heart disease, Type 2 diabetes, stroke, osteoarthritis, and certain types of cancer, including breast, colon, and endometrial cancer.

As the rate of obesity has increased, so has the market for weight-loss products. Several types of prescription drugs for weight loss are available in Canada. These are intended only for people who are medically at risk due to their weight. In addition, these prescription drugs are intended for use under a health care practitioner’s supervision as part of a weight management program that also includes appropriate physical activity and a reduction in the amount of calories consumed.

There are also many different types of natural health products (NHPs) being promoted for weight loss. They are sold over the counter in various retail outlets (e.g., pharmacies, health food stores, grocery stores) and are also available online. Under the right circumstances, some of these NHPs may be safe and effective when used as part of a weight management program that promotes a reduced intake of dietary calories and an increase in physical activity. However, there is no such thing as a magic pill that will make you lose weight effortlessly.

If you are considering the use of health products for weight loss, you should be aware of potential risks so you can make informed choices. It is not possible to list the risks associated with every weight-loss product on the market, due to the large number of products available. In addition, the risks of using health products depend on many factors, including:
the ingredients of the specific health product
whether the health product is used alone or in combination with other products for weight loss, prescription and non-prescription health products, as well as certain foods
the age and health status of the person using the product
However, the following situations represent misuse of weight-loss products, which could lead to serious health effects:

Ordering prescription drugs online that have not been prescribed for you by a health care practitioner who has examined you – Your health care practitioner needs to examine you to determine whether the benefits of using a prescription weight-loss drug would outweigh the risks in your specific situation.

Taking several different kinds of weight-loss products together , or taking weight-loss products in addition to other health products, without discussing possible risks with your health care practitioner – Certain kinds of weight-loss drugs and natural health products may interact with each other, with foods you eat, or with other medications you take, increasing the risk of adverse reactions. As well, health products for weight loss may not be recommended for individuals with certain health conditions.

Buying weight-loss products online from unreliable sources – Anyone can put up a Web site and offer health products for sale. If you order health products from unreliable sources, you have no guarantee that they will be safe, effective, and of high quality. Certain NHPs promoted online for weight loss have posed serious health risks because they have been mixed with prescription drugs or contaminated with heavy metals. Others products ordered online from unreliable sources, including prescription drugs, may be counterfeit, or contain ingredients other than those being advertised.

In some cases, products contain “proprietary” or trademarked/patented blends of ingredients. This makes it difficult to identify the content of each ingredient or determine whether some combination(s) of ingredients could harm your health.

Using health products “off-label” for weight loss, unless this has been recommended by your health care practitioner – Using a product “off-label” means using it for a purpose other than the authorized purpose(s). Products containing the herb Ephedra (or one of its active ingredients, ephedrine) and the herb bitter orange peel (or one of its active ingredients, synephrine) are often promoted off-label for weight loss. However, Ephedra and ephedrine are authorized by Health Canada as decongestants (conventional or traditional herbal medicines) and in homeopathic medicines. Bitter orange (Citrus aurantium) peel is used in traditional Chinese medicine for several conditions, including abdominal pain and constipation, and is used in food to make marmalade, but it is not authorized for the purpose of weight loss. Synephrine has not been approved for use in any health products to date. Health Canada has issued warnings about the potential risks of using Ephedra/ephedrine and bitter orange/synephrine for weight loss, including serious cardiovascular adverse reactions.