Can supplements affect blood pressure medicines?

Yes, some can. A supplement can push blood pressure up, add to what your medicine already does, or change the potassium level in your blood, and none of that shows up on a sales page. The National Center for Complementary and Integrative Health (NCCIH) tells anyone who takes any type of medicine to talk with a health care provider before using hawthorn, licorice or other herbal products, because some herbs and medicines interact in harmful ways. Your pharmacist can check your exact combination, and the best time to ask is before you buy.

This guide walks through the ingredient groups that come up most often next to blood pressure medicine: licorice, stimulants, heart herbs such as hawthorn, and potassium. It is general information, not medical advice. If you take blood pressure medicine, do not start, stop or change anything on your own.

Why would a supplement matter if you take blood pressure medicine?

The National Heart, Lung, and Blood Institute (NHLBI) lists the common blood pressure medicines: ACE inhibitors, angiotensin II receptor blockers (ARBs), calcium channel blockers and diuretics, which remove extra water and sodium from the body. It adds that many people need two or more medicines to manage high blood pressure. Each class works through a different pathway, so a supplement that touches the same pathway can matter.

There are three ways this tends to go wrong:

• The supplement raises blood pressure, working against the medicine.
• The supplement lowers blood pressure too, so the effects add up and you feel dizzy or faint.
• The supplement changes a body chemical the medicine also changes, potassium being the best-known example.

There is also a fourth risk that is not an interaction at all: believing a capsule can stand in for the prescription. NHLBI says that a heart-healthy eating pattern such as the DASH plan combined with a low-salt plan can be as effective as medicines in lowering high blood pressure. That is a statement about food and a doctor's plan, not about supplements. Our Blood Pressure 911 review flags a sales letter that encourages use with, or instead of, blood pressure drugs. Changing blood pressure medicine without a doctor can be dangerous.

Can licorice raise blood pressure?

Yes, and it is the clearest example of an herb that pushes the opposite way from your medicine. NCCIH says licorice contains glycyrrhizin, which can cause serious adverse effects, including irregular heartbeat and cardiac arrest, especially in large amounts or with long use. It adds that even small amounts of glycyrrhizin have been linked to severe effects in people who eat a lot of salt, in people with hypertension, and in people with heart or kidney conditions. Interactions between licorice and corticosteroids have also been reported.

A 2017 systematic review and meta-analysis in the Journal of Human Hypertension pooled 18 studies with 337 people who consumed a product with at least 100 mg of glycyrrhizic acid a day. Systolic pressure rose by an average of 5.45 mm Hg and diastolic by 3.19 mm Hg, and plasma potassium fell. The authors concluded that chronic licorice intake is associated with higher blood pressure and lower potassium even at modest doses, which matters most for people with existing cardiovascular disease.

Now the label problem. Our reviews found licorice in formulas sold for other goals, with no way to judge the amount:

• The RegenVive review notes licorice root extract at 50 mg with no glycyrrhizin percentage on the label.
• The BellyFlush review lists licorice root among eleven herbs with no amounts, and calls it the one case where a missing dose is a safety question as well as an effectiveness question.
• The GlucoTrust review lists licorice root with no amount and no word on whether glycyrrhizin has been removed.

NCCIH notes that licorice products without glycyrrhizin (deglycyrrhizinated licorice) might be safe for up to 4 months. A label that does not say which kind it uses leaves you guessing.

Do stimulants and "fat burners" matter?

They can. Many weight-management and energy formulas contain stimulant-type ingredients, and anything that raises heart rate or tightens blood vessels deserves a second look if you are managing blood pressure.

A 2022 systematic review and meta-analysis in Nutrients looked at p-synephrine, the compound in bitter orange (Citrus aurantium) used in many fat-burner products. Across 18 placebo-controlled human studies, both systolic and diastolic blood pressure rose after prolonged use, by 6.37 and 4.33 mm Hg on average. The authors wrote that synephrine tends to raise blood pressure and heart rate and that there was no evidence it helps weight loss. They called for further studies on its safety.

The CitrusBurn review shows what this looks like in practice. The formula contains p-synephrine from Seville orange peel with no stated amount, and the page is sold as "stimulant-free" even though green tea naturally contains caffeine. A reader with high blood pressure cannot judge their exposure from that label.

What about hawthorn and other "heart" herbs?

These are the ingredients blood pressure formulas lean on most, and they deserve a careful read. NCCIH says there is little or no quality evidence on hawthorn for most health conditions and conflicting evidence in heart failure. It reports one study in which a specific hawthorn preparation may have caused early heart failure progression, and says one possibility is that hawthorn interacted with drugs the patients were taking. No study has tested whether using it longer than 16 weeks is safe. Side effects can include dizziness, nausea, vomiting, diarrhea and muscle pain.

NCCIH also repeats an FDA warning from January 2024: some products labeled "tejocote root," or Mexican hawthorn, actually contained yellow oleander, a toxic plant that can harm the nervous system, heart, stomach and intestines. That is an ingredient-identity problem, and it is another reason to read a label closely and buy from sellers that name their makers.

Here is how the blood pressure formulas we reviewed handle it:

• The Bazopril review found six plant ingredients, including hawthorn, garlic and green tea, with no serving size, capsule count or milligram amount anywhere on the page.
• The Cardio Shield review notes that hawthorn, olive leaf, nattokinase, green tea, garlic and hibiscus share a single 570 mg proprietary blend with no individual amounts.
• The Blood Pressure 911 review notes seven herbs inside a 620 mg blend, again with no amounts.

A hidden amount is a problem for an interaction check in particular. Your pharmacist can reason about 500 mg of an ingredient. They cannot reason about a blend that says "570 mg total, ingredients in some order."

Why does potassium come up with blood pressure medicine?

A 2022 review of drug interactions with ACE inhibitors and ARBs, two of the medicine classes NHLBI lists, reports that the risk of hyperkalemia (too much potassium in the blood) may be enhanced when these drugs are taken together with potassium supplements, potassium-sparing diuretics or an NSAID. The review's conclusion is that prescribers and pharmacists must know which drugs interact with these medicines.

That does not make potassium a bad mineral, and this is no reason to avoid it in food. It means that a potassium supplement, an electrolyte powder or a salt substitute is a question for the person managing your medicines, who may want a blood test. Our ElectroSlim review notes potassium and sodium dodecanedioate on the label, with amounts not disclosed.

What should you ask before you buy?

1. Tell your pharmacist the exact name of every blood pressure medicine you take, and show the Supplement Facts panel.
2. Ask whether any listed ingredient raises blood pressure, lowers it further, or changes potassium or heart rate.
3. Check for licorice, bitter orange (synephrine), caffeine, green tea and potassium. If the label does not give amounts, say so.
4. Ask whether your kidneys, heart condition or salt intake change the answer.
5. Ask what symptoms to watch for, such as dizziness, a racing or irregular heartbeat or unusual weakness, and what to do about them.
6. Check your blood pressure at home if your provider has told you to, and take the log to your next visit.
7. Never stop or reduce a prescribed medicine because a sales page or testimonial suggests you can.

You can browse more formulas in our heart health category, and see how we score offers in how we review. Scores describe the sales offer, not how a product fits your prescriptions.

Frequently asked questions

Can I take a blood pressure supplement with my blood pressure pills?

Ask first. NCCIH advises anyone who takes any type of medicine to talk with a provider before using hawthorn or other herbal products. A supplement that also lowers blood pressure could add to your medicine, and one that raises it could work against it.

Can a supplement replace blood pressure medicine?

The sources we read do not support that. NHLBI describes treatment as lifestyle changes with medicines when they are not enough, planned with a provider. If a page suggests stopping a prescription, treat that as a warning sign.

Is licorice candy a problem too?

NCCIH notes that many licorice products sold in the US do not contain real licorice because anise oil is often used instead, and that real licorice is generally considered safe as a food ingredient. The concern is glycyrrhizin in larger or long-term amounts, especially for people with hypertension or heart or kidney conditions.

Should I worry about potassium in a supplement?

It depends on your medicine and your health history. Reviews list potassium supplements as a potential contributor to high potassium in people taking ACE inhibitors or ARBs. Ask your pharmacist and, if they suggest it, get a blood test rather than guessing.