Do gummy vitamins and supplements really work?

The supplements aisle at the drugstore has begun to resemble a candy shop, bursting with rainbow-coloured gummies, powders, pills, and tinctures that claim to increase energy, improve focus, boost skin radiance, help you fall asleep, and more. But can a gummy or capsule really do all that?

Traditional multivitamins are typically taken to “supplement” food intake, serving as backup for days when our diets are deficient. The new look-better-feel-better formulas are designed to work similarly, bridging nutritional gaps and acting as support for our bodies as they work overtime to manage stress, fatigue, and anxiety.

“Stress can deplete our nutrient stores, so it’s important to replenish through healthy eating and supplementation when needed,” says scientist Andrea Wong, senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition, a trade association. “Low levels of certain nutrients can affect mood, stress, and energy. For example, insufficient vitamin B6 levels can result in fatigue, concentration issues, and poor mood. And women taking birth-control pills are susceptible to (having low levels of) vitamin B6.”

In addition to vitamins like B6, the new crop of supplements may also contain other clinically researched ingredients, including minerals, herbs, amino acids, and enzymes. Take the botanical adaptogen ashwagandha, which has been shown to help protect against stress by reducing cortisol levels. It also may improve sleep quality because the ashwagandha plant’s leaves contain slumber-friendly triethylene glycol. Similarly, St. John’s wort can ease anxiety, depression, and ADHD by increasing the availability of serotonin and norepinephrine in the brain. And the neurotransmitter gamma-aminobutyric acid (GABA) slows down brain activity by blocking certain signals in the central nervous system, which can produce a calming effect. The concern with OTC supplements, most experts say, is not the efficacy of their ingredients but how much of those ingredients are actually in your gummy, pill, or powder.

"There is very little regulation over the claims made or the ingredients in (these supplements)," says psychiatrist Gerard Sanacora, professor of psychiatry at the Yale University School of Medicine and director of the Yale Depression Research Program.

While brands are required by the FDA to declare ingredients and their amounts on product labels, a study published in The American Journal of Clinical Nutrition in 2017, found that many supplements with multiple active ingredients contained one or more of them in amounts that exceeded what was on the labels. And if a brand won’t share its ingredients—or has a proprietary complex and won’t reveal what’s in it? “That’s a red flag,” says David A Merrill, psychiatrist and director of the Pacific Neuroscience Institute’s Pacific Brain Health Center at Providence Saint John’s Health Center in Santa Monica. 

To get a better sense of what you’re ingesting, experts point to third-party testing. The USP (U.S. Pharmacopeia) Verified mark indicates that the product does contain all of the ingredients on the label, in the stated amounts. And ConsumerLab.com, which has been called the Consumer Reports of supplements, conducts independent testing to certify the quality of dietary-supplement products, including their purity and potency.

The latter is especially important because, as the aforementioned study found, some supplements may contain more of an active than they claim. And taking too much of a good thing can be a bad thing. For example, St. John’s wort, used in some mood-boosting supplements, works similarly to most prescription antidepressants, and taking both could lead to serotonin toxicity. Likewise, melatonin, often included in sleep supplements, is a hormone that, in high doses, can act as a contraceptive and may inhibit the efficacy of some antidepressants. In fact, in parts of Europe, melatonin is available only by prescription. “We can’t just walk down to the local drugstore and buy testosterone or estrogen because that would be dangerous. We can, however, do this with melatonin, and I would argue that it can have equally big implications,” says Michael J Breus, a clinical psychologist. 

Experts interviewed for this piece strongly recommend telling your doctor about any supplements you’re taking to minimise contraindications—and to start a dialogue about other treatments that may be more effective than swirling anxiety-reducing powder into your morning coffee. While nutrient deficiencies may contribute to mild feelings of fatigue or malaise, they are unlikely to be the primary cause of more serious conditions like anxiety and depression. The diagnoses and treatment of those disorders are better left to a doctor. “If someone is struggling with mental illness and turning to a supplement in place of getting professional mental health care, I worry,” says Sanacora.

Bottom line: Supplements are not magic pills, even in cases in which a nutritional deficiency is contributing to your lack of focus, sluggishness, or dull skin. “If you’re talking about your metabolism or energy production, these are going to be long-term challenges to correct and manage,” says Merrill. “The ingredients found in these gummies have existed for decades, and their impact is typically pretty modest.

Wong concurs, "The body's overall nutritional status plays a role in skin health, so ensuring you have adequate levels of nutrients is important. But since nutritional interventions can often take time, consumers should not expect dramatic results."

There is also, of course, a potential placebo effect of taking a supplement, which can make you feel a difference, even if there is no discernible change to the brain or body. And there is evidence, says Sanacora, that taking a daily supplement may positively impact other behaviour, too. For instance, if you have a headache and take aspirin, that action can serve as a reminder to rest in a quiet room, drink water, or sip a small cup of coffee for a caffeine boost. 

By feeling you’ve gained some control over a stressful situation, you can positively impact the brain and body in ways that may be just as helpful as ingesting that OTC gummy or pill. As Sanacora says, “Sometimes the non-specific effects are the most powerful.”

This piece originally appeared in the February 2023 print issue of Harper's Bazaar US