What are supplement side effects?

Side effects vary by supplement and person. Digestive issues (e.g. nausea, bloating, diarrhea) are common with minerals like magnesium or iron, especially at high doses or on an empty stomach. Fat-soluble vitamins can build up if taken in excess. Herbs can interact with drugs or cause allergic reactions. Caffeine-containing products can cause jitteriness or sleep problems. If you notice any new or worsening symptoms after starting a supplement, stop use and contact your healthcare provider. Report serious reactions to the FDA (or your country’s regulator). This is educational only; not medical advice.