Many people are drawn in by pills and bottles on the supermarket shelves that promise weight loss, better hair, sharper eyesight or a heightened immune system. They hope that over-the-counter vitamin and mineral supplements will provide an extra health boost.

But that tempting bottle of cognitive supplements might be inaccurately labeled or, even worse, downright dangerous, according to a recent study conducted at several U.S. research centers including Harvard Medical School.

Supplements may contain unlabeled drugs

Of the cognitive enhancement supplements, or nootropics, studied, many either contained drugs not listed on the label, or showed drugs on the label that were not in the pill. In addition, quantities were often wrong; 75% of the listed amounts were inaccurate. Researchers also found high levels of drugs in nootropics that have not been approved for use in people.

In 2019, the Food and Drug Administration (FDA) even issued a statement about one of these drugs, phenibut, saying that supplements that contain it could not be called dietary supplements. Manufacturers of the supplements also did not accurately report what was in them to the National Institutes of Health’s database.

“It’s one thing for a physician to decide that a specific dose of a drug will benefit an individual patient. It’s entirely another for a healthy person to put an unknown quantity of a drug in their body,” said study author Pieter Cohen, MD, an associate professor of medicine at Harvard Medical School.

“[T]he risks of drugs always increase with higher doses. The products we examined contained up to four times more drug than the prescription dose and combined different combinations of drugs that have never been tested in humans.”

Earlier study showed problems with supplements

In a previous study, Dr. Cohen had found that numerous nootropics were not what they seemed. Eight out of 10 supplements examined contained traces of piracetam, or drugs like it. Piracetam is not approved in the U.S. Dr. Cohen called it “the grandfather of nootropics and said it seemed like a good place to start picking apart the world of brain boosters.

“Piracetam at usual dosages can cause anxiety, agitation, depression and weight gain,” he said, “but that is at usual doses. The risks of piracetam in over-the-counter supplements at larger-than-prescription dosages are unknown.”

One pharmacological relative of piracetam is available by prescription in the U.S., but Dr. Cohen explained it is not a brain booster but a serious drug to treat seizures and should only be taken if ordered by a doctor.

This is not Dr. Cohen’s first inquiry into the world of supplements. After he published a study in 2015 about β-methylphenylethylamine, a compound similar to amphetamine and found in weight-loss pills, he was sued by the manufacturer for $200 million.

Dr. Cohen won the suit and has remained a vocal skeptic of nootropics, saying in a 2018 article in GQ , “If you find a study that says that an ingredient caused neurons to fire on rat brain cells in a petri dish, you can probably get away with saying that it ‘enhances memory’ or ‘promotes brain health.’”

The path to debunking supplements

Perhaps he is such a skeptic because he has seen firsthand what can go wrong. “I was drawn into this area because of my clinical work. My patients were being harmed by weight-loss pills spiked with drugs,” he said. That started him on the path of debunking supplements.

So, where is the regulation? Because nootropics are a form of supplement, under FDA rules, they are not regulated the same way a medicine would be.

“Supplements are permitted to be advertised as if they will have health effects, even if no studies exist in humans,” Dr. Cohen said, “so, consumers would naturally expect them to work.” The FDA can step in if a supplement is shown to cause physical illness or death, but that level of regulation could let a lot of things slip through the cracks.

Despite all this, do brain boosters contain drugs that really work?

In a word, no. “Unfortunately, there’s no supplement I know of that will improve memory or clarity of thought,” Dr. Cohen said.

As a physician, his advice to patients looking to sharpen cognition is pretty simple. “I recommend to my patients that eating a healthy diet, getting plenty of exercise and sleep, while avoiding excess alcohol are keys to staying as sharp as possible.”

The take-home

Dr. Cohen had good and bad news for fans of vitamins and mineral supplements.

“I recommend them all the time to my patients who need them. Many of my patients have deficiencies of vitamins and minerals and require supplements for their health. However, if you don’t have a deficiency or medical disease, it’s unlikely you need extra vitamins.” He did make an exception for extra folic acid for women who are looking to get pregnant.

So remember, that promising bottle of supplements might not just be inaccurately labeled, it might be downright dangerous.

Sabrina Emms is a science journalist. She got her start as an intern at a health and science podcast out of Philadelphia public radio. Before that she worked as a researcher, looking at the way bones are formed. When out of the lab and away from her computer, she’s moonlighted as a pig vet’s assistant and a bagel baker.