Why blood-pressure medications need care
Blood-pressure medicines are dose-sensitive, and some supplements can shift their effect or independently affect blood pressure or potassium. NCCIH's guidance is that supplements can increase, decrease, or dangerously interact with medications [1].
Supplements that can work against you
- Licorice (with glycyrrhizin). Real licorice root can raise blood pressure and lower potassium, working directly against BP control. (Deglycyrrhizinated 'DGL' licorice lacks the compound responsible.)
- Stimulant and 'energy' supplements. Hidden or stacked stimulants can raise blood pressure (see [hidden stimulants](/learn/hidden-stimulants-in-supplements)).
- High-sodium effervescent products. Some fizzy supplements carry significant sodium.
The potassium problem
Several BP medicines — ACE inhibitors, ARBs, and potassium-sparing diuretics — raise blood potassium. Adding a potassium supplement (or potassium-based salt substitute) on top can push potassium too high, which affects the heart. People with reduced kidney function are at particular risk [2].
Supplements that can weaken BP drugs
St. John's wort speeds the breakdown of many medicines and can lower blood levels of some blood-pressure drugs, reducing their effect — see [St. John's wort interactions](/learn/st-johns-wort-drug-interactions).
Practical guidance
- Tell your prescriber and pharmacist about every supplement, including 'natural' BP or heart products.
- Don't add potassium (or potassium salt substitutes) on ACE inhibitors, ARBs, or potassium-sparing diuretics without medical guidance.
- Avoid glycyrrhizin-containing licorice if you have high blood pressure.
- Monitor as advised, and don't start or stop a supplement around a medication change without input — see [supplements and medications](/learn/supplements-and-medications).