Are Your Supplements Actually Doing Anything—or Just Costing You Money?

Walk into almost any store and you will find supplements promising better sleep, stronger immunity, more energy, healthier joints, and sharper thinking. But do they really work?

The honest answer is: some do, for the right person and the right reason. Others have little evidence behind them—and a supplement can sometimes cause harm.

1. Do supplements really work?

A supplement is most likely to help when it addresses a specific nutritional deficiency, increased nutritional need, or medically recognized condition.

Examples include:

• Vitamin B12 for someone with a confirmed deficiency

• Folic acid before and during early pregnancy to help prevent neural tube defects

• Iron for diagnosed iron-deficiency anemia

• Vitamin D when testing and medical evaluation indicate it is needed

• Certain supplements prescribed for conditions that interfere with nutrient absorption

That is very different from taking several products “just in case.”

A 2024 study published in JAMA Network Open followed more than 390,000 generally healthy adults. Daily multivitamin use was not associated with living longer. The study did not prove that multivitamins are useless for everyone; it showed that routinely taking one should not be treated as a proven longevity strategy.

2. How do I know whether I need one?

Start with the reason you are considering it.

Ask yourself:

• Am I treating a diagnosed deficiency?

• Has a healthcare professional recommended it for my age, diet, medication, pregnancy, or medical condition?

• Am I hoping it will treat symptoms without knowing what is causing them?

• Can I get this nutrient consistently through food?

Fatigue, hair loss, muscle weakness, poor concentration, and numbness can have many causes. Buying a supplement based on symptoms alone may delay the correct diagnosis.

A clinician can review your diet, health conditions, medications, and—when appropriate—laboratory results before recommending a product and dose.

3. Does “natural” mean safe and effective?

No. “Natural” is not proof that a product works or that it is harmless.

Unlike prescription drugs, dietary supplements generally do not receive FDA approval for safety and effectiveness before reaching store shelves. Manufacturers are responsible for ensuring their products are safe and properly labeled, while the FDA generally acts after a product enters the market.

Supplements may also:

• Interact with prescription or over-the-counter medicines

• Increase bleeding risk

• Affect blood pressure or blood sugar

• Interfere with medical tests

• Cause liver, kidney, or digestive problems

• Provide excessive amounts when combined with fortified foods and other supplements

More is not always better. High doses of some vitamins and minerals can be harmful.

4. How can I choose a more trustworthy product?

Read the entire Supplement Facts panel—not just the claim on the front.

Check for:

• The amount in one serving

• The number of pills required per serving

• Percent Daily Value

• Proprietary blends that conceal individual ingredient amounts

• Duplicate ingredients found in your other supplements

• Added sugars, colors, fillers, allergens, or stimulants

• An expiration date and identifiable manufacturer

• Independent quality certification, such as USP or NSF

Third-party certification can provide added assurance that a product contains the listed ingredients and has been checked for certain contaminants. It does not prove that the supplement will work for your particular concern.

Be especially cautious of products promising to “cure,” “detox,” “melt fat,” replace medication, or produce dramatic results quickly.

5. Are supplements worth buying?

They may be worth it when there is:

1. A clear reason for taking the supplement

2. Reasonable evidence that it can help

3. A dose appropriate for your needs

4. A product with credible quality verification

5. A check for medication interactions and safety concerns

They are less likely to be worth the money when the reason is vague, the promised results sound too good to be true, or several products contain overlapping ingredients.

The Maria Verdict

Supplements can fill a real nutritional gap, but they cannot automatically create better health.

Before buying one, ask: What specific problem am I trying to solve, and what evidence shows this product can solve it?

Use supplements to address an identified need—not because a label, influencer, or advertisement makes you afraid you are missing something. Check the dose, review your medications, look for credible independent testing, and remember that a supplement should supplement a healthy diet—not replace one.

References

1. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need to Know⁠.

2. U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements⁠.

3. Loftfield E, et al. “Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts.” JAMA Network Open. 2024;7(6):e2418729. Read the journal article⁠.

4. National Institutes of Health, Office of Dietary Supplements. Dietary Supplement Fact Sheets⁠.

5. U.S. Food and Drug Administration. FDA 101: Dietary Supplements⁠.