Supplements and vitamins constantly go viral with claims that they can transform your health just by integrating these pills into your daily routine. But before you add to cart, take a pause and make sure you’re buying exactly what you think you are. In the US, supplement companies can’t explicitly claim to cure, treat, or prevent a disease. So how can you know which ones are legit, and which ones might just be a money grab?

Besides being potentially ineffective and a waste of money, some supplements have been shown to contain heavy metal, fungi, or even mold contaminants, and others contain just a fraction of what they claim to.

OB/GYN and bestselling author Dr. Jen Gunter says that you can easily discern snake oil salesmen from legitimate supplements grounded in good science with these 3 tips.

JEN GUNTER: I get asked a lot about supplements and it's a really big and sometimes even confusing topic. And in addition, there are so many ads that come to us all the time on social media, either clear ads where someone's, you know, pushing a vitamin, or soft ads where an influencer is just talking about it off the cuff and you don't actually know if it was paid for or not.

- Like if you wanna optimize your health, yeah, supplements are very beneficial.

- Very beneficial, but I think for you and me, it's a duh, but I think...

- So the truth is there are very few supplements that have good evidence-based medicine to support them. And the term supplement is really meant to be a dietary supplement, meaning something that is supplementing a dietary shortfall. The greatest example is probably prenatal vitamins. There is good evidence-based medicine to support using prenatal vitamins because the average person doesn't get enough folate and other micronutrients in their diet to support a real healthy pregnancy. Another common one is if you have iron-deficiency anemia, it's really hard to get enough iron from your diet to treat that. And so we might recommend an iron supplement. So those are what we would consider, sort of, the evidence-based examples. And that is not an inclusive list, but that's how to think about it. Then there's this other class of supplements, meaning a reported medical benefit. Although in the United States, supplement companies can't actually say their product does anything. They all have these little FDA disclaimers, but that might be some things that are grounded in pretty good science or good science even, so magnesium to treat constipation. But there's also things that aren't grounded in good science like black cohosh for hot flashes. Another common one that we see all the time is biotin for hair growth, but there's no data to support that. So there's a wide range of things that are potentially have good science behind them, and things that have no science behind them and things that might be kind of in between. And then there are another category of supplements where there's a whole bunch of vitamins and minerals, and herbals and botanicals all lumped together in a product where there's an insinuation that there's some kind of benefit for your organ or for your health, or like ovary support or adrenal support, or thyroid support, or metabolism booster or fat burner. And none of these are studied in any meaningful way, and many of them are actually adulterated. And that is one big concern with supplements is you do not know what you are getting. So how do you decide? Three ways to think about supplements. One, is this something you really need to take? Is there good evidence to support it? Well, you wanna ask your doctor if the supplement you wanna take falls in a good recommendation, or places to look would be the CDC, Centers for Disease Control. If it's for a reproductive health issue, it might be the American College of Obstetricians and Gynecologists. And also in the U.S., the U.S. government has the Office of Dietary Supplements. Number two, who is recommending this to you? Is it someone who's selling a product, or is this someone saying, "these are the recommendations of multiple medical societies"? So look at the source of the recommendation. And number three, you wanna take a product that has been tested by a third-party. For example, a USP verified label means that there's been third-party checking. That's really the best that we can do because in the United States, we don't have the ability of the government to require testing for purity. And be very wary about Ayurvedic products because they are actually very likely to be contaminated with lead, about 20% of them are. Especially with products that are for libido, for metabolism, for sport enhancement. Those products have a much higher risk of contamination. This is a huge problem, and it's important because one, you wanna make sure that the product you're taking isn't contaminated with heavy metals or mold or fungi or things like that, but you also wanna make sure it contains what it claims. And that's actually why pharmaceuticals have a standard, so none of these things happen. They get tested and that doesn't happen with supplements.