It is nearly impossible to watch TV, surf the internet, or walk into a supermarket, without being bombarded with advertisements for a miracle dietary supplement that will change your life. Just take one of these, they proclaim, and you will not only lose weight, but you’ll be able to concentrate more too. According to a 2011 study by the Center for Disease Control, more than half Americans take a dietary supplement daily. It is clear that the advertising is working. What apparently does not work are the supplements. A new Frontline documentary, Supplements and Safety, investigates this fraudulent and dangerous industry.

“For the most part, they are totally unregulated. It’s a bit shocking and I must say that it’s one of the things that shocked us as well as we sort of launched into this investigation.” Frontline correspondent Gillian Findlay said on Boston Public Radio Tuesday.

With pharmaceuticals, the FDA ensures the quality of a drug with a rigorous series of tests and regulations. This is not the case for supplements. “Manufactures do not need to get pre-market approval to say that this drug is first of all effective for what they're saying and even more frightening if it’s even safe,” Findlay said.

In 2012, Dr. Steven Newmaster conducted a DNA study of supplements at Guelph University. The study showed that 60 percent of the 44 herbal supplements they tested had contained ingredients not labeled. One in three of the supplements tested did not contain any of the ingredients advertised.

“In 2013, the Annals of Internal Medicine essentially put out an editorial saying, they called it Enough is Enough, they’re saying for your average reasonably nutritioned man or women, there is no need for any additional supplementation to your diet. People are wasting their money,” Findlay said.

Findlay says, that common thought has been that taking supplements can not hurt. They may not help, but what is the harm of having some extra vitamin D. It turns out that this type of thinking can be incredibly dangerous.“The science is showing there is a potential for harm... It might well hurt you,” Findlay said.

Supplements and Safety airs tonight at 10 pm on WGBH 2

Gillian Findlay is a correspondent for Frontline. Listen to her interview with Boston Public Radio above.