Medical Disclaimer

No content on this site diagnoses, treats, cures or prevents any disease or condition. We summarise published research and describe how products differ. We do not know your medical history, your kidney and liver function, your medication list or your risk factors — and all of those change what is appropriate for you.

Always talk to your physician, pharmacist or another qualified clinician before starting, stopping or changing any supplement, and never delay seeking care because of something you read here.

• Take prescription medicine of any kind. Supplements can reduce or amplify how drugs work — anticoagulants, thyroid medicine, antibiotics, blood-pressure and diabetes medicines are common examples.
• Have kidney disease, liver disease, heart disease or a bleeding disorder.
• Are pregnant, planning a pregnancy or breastfeeding. Most supplements have not been established as safe in pregnancy.
• Have surgery or a procedure scheduled. Tell your surgeon and anaesthetist about every supplement you take; many teams ask patients to pause supplements one to two weeks beforehand.
• Are undergoing cancer treatment. Antioxidant supplements in particular must be cleared with your oncology team.
• Are caring for, or buying supplements for, an older adult with multiple prescriptions.

If you experience chest pain, difficulty breathing, sudden weakness, confusion, severe bleeding, a severe allergic reaction or any other emergency symptom, contact emergency services immediately. Do not consult this website.

Dietary supplements are not reviewed for safety and effectiveness in the way prescription medicines are. Statements on this site have not been evaluated by any regulatory authority. Product quality varies between manufacturers and between production lots.

Research changes. We date every review and update cornerstone content, but a page you are reading may not reflect a study published last week. Where a reference is still being verified by an editor, it is labelled as a citation placeholder rather than presented as a confirmed source. Read How We Review Supplements for our full sourcing rules.