Many items sold in stores are not entirely safe for you to take.
Most people may not realize that weight-loss supplements aren’t approved by the FDA or tested in the United States. In the United States, there is little to no testing for efficacy or safety prior to a bad outcome. This statement means that a fatality or illness is required prior to the government to step in and test a supplement. Unfortunately, the FDA does not have the authority or the manpower to regulate the manufacturing and testing of supplements. Similar to the snake oil salesmen in the old West, supplement companies have free reign to sell you whatever they want. There is no guarantee that the contents of those powders, capsules, or pills contain even the ingredients that they claim they do.
Most Americans think that if you buy them in the store that they are rigorously tested and safe. This statement could be nothing further from the truth. Let look at one supplement of the past that was used for weight loss. There are very few folks who do not remember Ephedra. Many dieters tried this “miracle cure” because it was publicized to increase your metabolism and allow you to lose weight without dieting and exercise. Ephedra was classically stacked with two other compounds to create the ECA or ephedra, caffeine, and aspirin stack. Although there is substantial research to show that ephedra increased metabolism and weight loss, the supplement was banned in 2004 because of the side-effects which included cardiac arrhythmia, stroke, aneurysm, and heart attack.
Many people will tell you that dietary supplements are considered safe at the recommended dosage but maybe have adverse health effects at higher doses, but they are not rigorously tested, what is a recommended dose and what is safe? The side effects of most supplements are on par with even the worst medicine. They may interact with other supplements or medication and may be unsafe for people with medical disorders and they should be off-limits for pregnant and breastfeeding women. Why would you even want to risk it?
The bottom line: We have no idea if they re safe until some dies or have a bad outcome (stroke or heart attack). I would recommend against most and if you are going to take them, do your research. Taker beware!