Dietary Supplements: What Works, What to Watch For

Around half of adults take dietary supplements. Some help, some do nothing, and a few can cause real harm when mixed with prescription drugs. This page gives clear, usable advice so you can pick supplements that are more likely to help and less likely to hurt.

How to choose a safe, effective supplement

First, ask what you want the supplement to do. Boost energy? Fill a gap in your diet? Support liver health? If you’re trying to treat a disease, talk with a clinician first — supplements don’t replace proven medical care.

• Check the label: look for exact amounts of active ingredients, not vague terms like "proprietary blend."
• Prefer third-party testing: NSF, USP, or ConsumerLab seals mean the product contains what the label claims and is free from certain contaminants.
• Aim for evidence: search for randomized trials or systematic reviews. For example, omega-3s have solid data for heart health in some groups; artichoke extract shows some support for digestion and liver enzymes in small studies.
• Avoid miracle claims: no pill will cure chronic disease overnight or replace a balanced diet.

Smart use: dose, timing, and interactions

More is not always better. Follow the label or the dose your clinician recommends. Fat-soluble vitamins (A, D, E, K) need a meal with fat. Iron works better on an empty stomach but can upset some people, so split the dose or take with a small snack.

Watch interactions closely. St. John’s wort can reduce levels of many prescription drugs, including some birth control pills and antidepressants. Ginkgo and fish oil can increase bleeding risk when combined with blood thinners. If you take blood pressure, thyroid, diabetes, or anticoagulant meds, check with your prescriber before starting anything new.

Keep a running list of everything you take—prescription drugs, over-the-counter meds, and supplements—and share it with your pharmacist or doctor. They can spot interactions you might miss.

Quality matters: store products in a cool, dry place and check expiration dates. If a supplement smells off, discolors, or causes a new rash, stop it and get medical advice.

Finally, track results. If a supplement aims to improve sleep or digestion, give it a fair trial (often 4–8 weeks) and note measurable changes. If nothing changes or side effects appear, stop and reassess.

At GenMedicare, we break down supplements and the science behind them in plain terms so you can make smarter choices. If you’re unsure about a product or a dose, reach out to your healthcare team—getting a quick professional check can save time and risk.