Supplements That Promise to Make You Prettier, Healthier, Better Are Everywhere. Here’s What the Science Says

Julia Ries
·14 min read

CSA-Printstock/Getty Images/Amanda K Bailey

Walk into pretty much any grocery store or pharmacy and you’re likely to see shelves lined with supplements: pills and gummies and capsules and powders and wellness shots that claim they’ll make you calmer, sharper, happier, thinner, younger-looking, better. On social media, the story’s the same: Ads target your deepest insecurities (how do they know I have, in fact, been feeling bloated lately?!) and/or promise a quick fix for your missing sex drive (like, okay, kinda presumptuous). Meanwhile, influencers with massive followings offer glowing testimonials of colloidal silver for sinus infections, collagen pills for wrinkles, and NAD+ (whatever that even is) for healthy aging.

It can be hard to resist the siren song of any product that supposedly will do wonders for your well-being with minimal effort on your part. I get it: I’ve bought vitamin C gummies when I felt a cold coming on and experimented with melatonin when I was sleep deprived. I tried magnesium powder at one point (for what, I do not know) and decided, for no real medical reason, that it would be in my best interest to take a women’s daily multivitamin (the gummy kind that tastes like strawberries, of course).

Did they work? In truth, I have no idea. But probably not, according to the experts I spoke with for this story. The general consensus is that the benefits of supplementation are largely unproven and most people don’t need them. Many of these products make spurious-at-best claims, are a waste of your money, and, in some cases, can even result in bad health consequences. “Best case scenario: You just pee it out,” Aimee Bernard, PhD, an assistant professor in the Department of Immunology & Microbiology at the University of Colorado Anschutz Medical Campus, tells SELF. So before you pop a pill based on its too-good-to-be-true promises, here’s what the science says about taking supplements.

First, it’s important to know that most people don’t have nutrient deficiencies.

If you eat a decently balanced diet, you are most likely getting all the vitamins and minerals you need from your food. (If you’re curious, here are the government’s recommendations for daily nutrient intake.) You don’t need to be eating, say, organic brown rice, wild-caught salmon, and fresh broccoli around the clock to avoid deficiencies; in general, as long as you’re consuming a reasonable variety of fruits, vegetables, whole grains, and proteins, you shouldn’t need any supplements, the Academy of Nutrition and Dietetics states. “Assuming you eat, you surely get some nutrients,” Christopher Gardner, PhD, the director of nutrition studies at the Stanford Prevention Research Center, tells SELF.

Plus many foods in the US are fortified, or intentionally enriched, with key nutrients to prevent deficiencies—so even if your go-to bowl of cereal is fairly high in added sugar, it might still be packed with folic acid, iron, and vitamin B12.

If you’re vegan or vegetarian, it might be a little trickier to get all the vitamins and minerals you need, particularly vitamin D, iron, and vitamin B12, but with a bit of research and careful planning it’s still very possible to do so, Dr. Bernard says. So many (too many!) people believe that it’s important to take a daily multivitamin—but, experts largely agree, most don’t need to.

Granted, there are some exclusions. Your diet might lead to deficiencies if you have, say, chicken fingers from the drive-thru for every meal, Dr. Bernard says, because food-processing often strips foods of vitamins and minerals. If you’re predominantly eating a highly processed diet—like potato chips, canned soups, white bread, and frozen meals—then, yes, you might want to be tested for nutrient deficiencies, Dana Ellis Hunnes, PhD, MPH, RD, a senior clinical dietitian at UCLA Medical Center and assistant professor at UCLA’s Fielding School of Public Health, tells SELF. (Having perpetually low levels of certain vitamins or minerals prevents your body from functioning properly and ups your risk of certain chronic conditions, like heart disease and diabetes). Don’t let that freak you out too much, though. “Even then, most Americans do not have many deficiencies,” she clarifies.

In that case, it’s more likely that you’d deal with an inadequacy, which means you’re eating less than what’s recommended. The consequences aren’t as severe as deficiencies, but this can still mess with your system and cause low energy, irritability, and poor concentration, for example. In that scenario, the best way to make sure you’re getting the nutrients you need isn’t by throwing a random pill into the mix, but through tweaking your diet, ideally with the guidance of a registered dietitian or a physician. Studies have found that getting your nutrients from food is far more effective at preventing chronic health issues compared to supplements.

Most supplements don’t offer the fantastic health benefits their manufacturers claim.

It’s easy to feel enticed by all the remarkable things supplements swear they can do for you. Who wouldn’t be a little intrigued by a once-daily cherry-flavored chew that can supposedly make your hair grow faster and your nails stronger? But those claims are, sorry to be blunt, bullshit. “There are so many supplements now that are marketed to people that claim to have health benefits that they actually do not,” Dr. Bernard says.

You’d be surprised by how easy it is for a company to slap a health claim onto a packaging label. While brands can’t outright say their product will treat, diagnose, prevent, or cure diseases (that’s illegal—only drugs can do this after FDA-regulated clinical trials show they can), they basically just need to reference any existing scientific study to be able to state there’s some sort of health benefit like this pill supports women’s health or strengthens your bones. Dr. Gardner says—half-kidding, half-not—that research could be as simple as one small study conducted in rodents. (In case you aren’t aware, data based on rat studies isn’t easily applied to humans and is, therefore, less reliable than double-blind, placebo-controlled studies, which are studies when neither the participants—ideally a large, diverse pool of people—nor the researchers know who’s taking a supplement and who’s taking a fake pill to minimize the risk of various biases.)

“They don’t have to even conduct the study; they just have to look into the existing literature and see if anyone ever studied this thing to say that it worked,” Dr. Gardner says. Let’s say there’s a study out there that found fiber promotes bowel movements (spoiler: there are plenty). Per FDA guidelines—known as “structure/function claims”—a supplement company could say its tasty little fiber gummy can help you poop better. The brand just has to add a disclaimer that those statements haven’t been evaluated by the FDA. This, in theory, shows the benefits are plausible if not proven. Problem is, a supplement might be meaningfully different from what was actually studied. (For example, the research might have been based on the positive effects of getting fiber from a food, not a pill or powder.) “The bar is so low,” Dr. Gardner says.

The research on the supposed advantages of supplements as a whole is limited, conflicted, and unconvincing, according to the National Institute of Health. On the other hand, there are plenty of reliable studies concluding that most people don’t need supplements because, by and large, they don’t offer any real health benefits. For instance, a recent analysis that evaluated over 80 studies (including more than 700,000 people) determined vitamin and mineral supplementation was associated with little, if any, benefit in preventing cancer, cardiovascular disease, and death. And there’s no definitive evidence that hair, skin, and nail gummies, probiotic pills, or fish oil capsules deliver on what they say they do, either.

There is one glaring reason why food is more beneficial to your health than any supplement could be: Bioavailability, or the extent and rate at which a substance, like a nutrient, is absorbed by your body. As Dr. Bernard puts it: “It’s kind of a big deal.” Supplements might be packaged in a form that your body can’t use well. Take magnesium, for example: There are so many different types of formulations of this mineral (powders, pills, capsules, liquids) and the bioavailability can be drastically different depending on the source. You’ll be able to absorb some versions better than others, and there are formulations and doses your body can’t make use of at all. At that point, “it really is just expensive pee,” Dr. Bernard says. You might wonder if there’s an easy way to determine what’s got top-notch bioavailability but, no, of course there isn’t, that would be way too convenient. “All of [the brands] will say: This is the best one,” Dr. Bernard says.

This is where food has the upper hand. “Supplements do not react in our bodies the same way a whole food does,” Dr. Hunnes says. She once had a colleague ask her what ingredient makes a raspberry so nutritious. Her answer: the whole berry. Everything in it—the fiber, vitamin C, calcium, and magnesium—work synergistically together to amplify the effect of any given nutrient. With supplements, a single nutrient is isolated from the raspberry and people expect it to be as healthy as the entire fruit, she says, but that’s not the case. “There are so many nutrients and enzymes and other naturally occurring chemicals in foods that work together to give us the nutrients we need,” Dr. Hunnes says.

Supplements have little regulation and quality control, which is less than ideal for stuff you’re putting into your body.

When it comes to making sure supplements are safe and effective, it’s the Wild West out there. The Dietary Supplement Health and Education Act (DHSEA), passed in 1994, essentially cut dietary supplement makers loose from the FDA’s regulations for prescription drugs. Now, supplement manufacturers don’t need to conduct clinical trials on their products or otherwise provide evidence that they have their marketed effect; they don’t even need to prove what’s inside the bottle is the same as what’s on the label, Dr. Bernard says. The agency only gets involved if a product that’s already on the market is causing people harm. “Supplements are generally considered safe until shown to be detrimental,” Dr. Hunnes says. The result: “It’s a free-for-all,” Dr. Gardner says.

This is vastly different from how the federal government oversees pharmaceutical medications. The FDA requires prescription drugs to undergo multiple clinical trials—first in small groups of people, then in many more folks—that thoroughly prove the drug is safe and effective and won’t cause atrocious side effects before the general public can use it. “Supplements do not need these types of studies,” Dr. Hunnes says.

Several scientific reports have found that supplements are labeled inaccurately. A 2023 study found that 89% of the 57 dietary supplement products researchers analyzed didn’t accurately list ingredients and 12% contained compounds that the FDA bans. This doesn’t always mean that whatever a manufacturer claims is in the supplement is a flat-out lie (many companies claim to do their own rigorous testing and say they utilize third-party services to verify products are free of contaminants). It just shows you how unregulated it is, Dr. Bernard says.

In addition, many brands hitch their (marketing) wagon to being “all natural.” Dr. Bernard calls this the appeal-to-nature fallacy: Supplement companies use the word “natural” hoping it’ll make people think they’re putting something “pure” in their bodies. “Just because it’s natural does not mean it’s good for you,” Dr. Bernard says. There’s plenty of stuff found in nature that’s horrible—sometimes poisonous!—for humans. Kava, which is currently having its moment on TikTok as a supposed way to reduce stress and anxiety, can cause liver disease. Even too much water can be toxic (and what’s more natural than that?).

Supplements can seriously screw with your body and put your health at risk, even after you stop taking them.

In most cases, taking a multivitamin, even if you don’t need to, won’t harm your health. Your body will filter it out and it’ll pass right on through ya—you are, quite literally, flushing money down the toilet. In other instances, taking a vitamin you don’t need can trigger a benign but unpleasant problem. Downing more than 2,000 mg of vitamin C a day, for example, can give you the runs.

Sometimes, the risks can be more serious. The worst case scenario is supplement overdosing, which is when you ingest way too much; this is more of a concern with herbal supplements, such as chaparral or kratom, because they tend to use concentrated extracts from the plant (not the plant itself), which can be like taking a super dose of the herb. But it can also occur with staples like vitamin A, vitamin D, and fish oil. Overdoing it with supplements can damage your organs, like your kidneys and liver, and diminish how well your body filters out toxins and waste as a result, Dr. Bernard says.

The whole lack of federal regulation comes into play here too. “Again, we don’t know, for the most part, if the label is accurate for what’s inside—if it contains what it says or if it’s an accurate dosing,” Dr. Bernard says. Many supplements contain too much or too little of whatever nutrient they’re allegedly boosting; in one 2023 study, researchers tested 25 melatonin gummy brands and found they contained anywhere from 74% below to 347% above the amount of melatonin listed on the label—or, as we noted above, the completely wrong ingredients. As a result, people can overdose on supplements without realizing it.

In addition, many supplements interact with medications, including SSRIs, immunosuppressants, blood-thinning drugs, and statins, and impact how well they work, Dr. Hunnes says. For example, ginkgo can increase the risk of bleeding if you take warfarin (a blood-clotting drug), and St. John’s-wort, which is touted as a supplement for depression relief, may reduce the effectiveness of oral contraceptives and protease inhibitors (which are antivirals used to treat infections like HIV and COVID). Zinc, calcium, and magnesium can prevent your body from absorbing certain antibiotics. Even something as seemingly innocuous as vitamin D can mess with diuretics and antipsychotics, evidence suggests.

It’s so, so important to consult with a health care provider, like your primary care doctor, if you took, are taking, or want to try any supplements—even if your doctor doesn’t ask you about supplements directly, it’s crucial to let them know about anything you’re downing on a regular basis. A professional can look at your overall health, weigh the pros and cons of whatever you’re considering, and let you know whether or not it’s a good idea. “A lot of the time, the answer may be no,” Dr. Bernard says. Depending on your symptoms—maybe you constantly feel fatigued or winded while exercising—they may want to run a blood test to see if you’re lacking nutrients.

There are certain medical instances—such as iron deficiency, pregnancy, eating disorders, cystic fibrosis, and digestive disorders like Crohn’s disease—that are scientifically proven to benefit from supplementation. If you do need to take something, your doctor can help you find a reliable brand that’s been adequately tested (since, as we now know, that’s often not the case). For everyone else: “If you do not fall into these categories of chronic diseases or other ailments that require higher-dose supplementation, for the most part, you’re spending a lot of money unnecessarily on supplements that probably aren’t doing much for you,” Dr. Hunnes says.

So resist the urge to buy the herbal elixir that promises to heal your gut as you walk down the supplement aisle at Whole Foods. Swipe straight past the influencer telling you that kava miraculously fixed their anxiety. Yes, it would be great if there were an easy way to boost your health, or go to sleep, or get stronger nails without having to worry about what you eat, Dr. Hunnes says. The reality is, taking a random pill isn’t actually a quick fix. “In the long run, popping pills is more expensive, frequently less healthy, and sometimes even dangerous,” Dr. Hunnes adds. “We did not evolve to eat nutrients. We evolved to eat foods.”

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Originally Appeared on SELF