Supplements

Millennials and Gen Z typically took more supplements than other age groups across vitamins, proteins, minerals, and herbal supplements, according to 2025 data from a Global Consumer Insights Survey conducted in 55 countries. Roughly two-thirds of Gen Z respondents stated they'd taken vitamins in the past 12 months. (Some users may experience a paywall.)

A 20-year study by the National Cancer Institute involving almost 400,000 people found that daily multivitamins did not help people live longer. In some cases, these vitamins also increased the risk of death. Although some subpopulations—such as those with documented vitamin deficiencies and pregnant individuals—should take vitamins, daily multivitamins should not be taken uniformly by adults. Instead, patients should discuss vitamins with their clinicians and consider baseline vitamin testing before starting vitamin regimens.

Too much of vitamins A, D, E, and K (which are fat-soluble) can build up in the body and cause serious health problems, including liver damage, kidney stones, and blood clotting irregularities. Excess iron and calcium can also make it harder for the body to absorb other needed nutrients.

The US Food and Drug Administration does not regulate products including vitamins, probiotics, and herbal mixes as drugs due to the Dietary Supplement Health and Education Act of 1994, which amended the Federal Food, Drug, and Cosmetic Act. Because dietary supplements are regulated as a subcategory of foods, inspectors do not assess whether dietary supplements work as advertised before sale.

Memorial Sloan Kettering Cancer Center has created this searchable resource of herbal supplements to inform the public about the purported uses of herbal therapies, the existing evidence about them, their mechanism of action, and any concerns about potential herbal supplement and drug interactions.

The black-and-yellow USP-verified program seal on a dietary supplement bottle means that the nonprofit US Pharmacopeia tested a sample of the product and verified that it was made in a facility with good manufacturing practices and that it will dissolve in the body. Their certification also means they tested to confirm that the product contains the ingredients listed on the bottle at the specified levels, and that it doesn't contain harmful levels of certain dangerous contaminants.

Consumer Reports' tests of more than 20 supplement powders and shakes in 2025 found that more than two-thirds of them contain unsafe levels of lead. Some contained 10 times the amount of lead that's considered acceptable to ingest in a day. The levels they found, in some cases, were even higher than when they tested the products 15 years earlier.

The group purchases supplements and tests them for accuracy. When it tested 26 popular B vitamin supplements, it found five failed their tests because they provide either significantly less or much more of the ingredients than listed. This type of product-label mismatch can occur because the FDA does not regulate these products as it would a drug.

Beginning in our 20s, the amount of this protein in our skin, muscles, and connective tissue declines. But independent, high-quality studies—like those that are double-blind—have not yet shown a significant association between their use and evidence of it improving skin elasticity, reducing wrinkles, or combating hair loss. Some collagen supplements do seem to help with joint pain and knee function, but NPR cautions that studies on that purpose are industry-funded.

Eating collagen-rich foods won't lead to more collagen in the body because your digestive system breaks down consumed collagen into amino acids. Instead, eating a healthy diet of proteins and greens helps your body to produce collagen. Collagen supplements derived from animal skin and bones are typically sold in a prebroken-down peptide formulation called hydrolyzed collagen so they can be absorbed through the gut into the bloodstream.