Index of Herbs

Concern guide

Herbs for Heart and Circulation

Psyllium, horse chestnut, garlic, hawthorn and more as support for a heart-healthy lifestyle, with what research shows.

13 herbs reviewed

Updated October 12, 2026

Heart and circulation concerns range from silent risk factors to everyday discomfort. High blood pressure and high cholesterol usually cause no symptoms for years while quietly raising the risk of heart attack and stroke. Heart failure, angina and abnormal heart rhythms can cause breathlessness, chest pain, fatigue or palpitations. On the vein side, chronic venous insufficiency brings heavy, aching, swollen legs and varicose veins.

Herbs can be a supportive part of a heart-healthy lifestyle built on not smoking, staying active and eating well. Prescribed medicines such as statins and blood pressure drugs are the proven way to reduce heart attacks and strokes, and the herbs here are best used alongside them, with your prescriber in the loop. Several have encouraging trial results: psyllium lowers LDL cholesterol, horse chestnut eases heavy, swollen legs, hibiscus tea may modestly lower blood pressure, and garlic and hawthorn, two well-loved traditional heart herbs, show promising effects on cholesterol, blood pressure or heart failure symptoms. Never stop or reduce a statin, blood pressure medicine or blood thinner on your own, and tell the prescriber about any herb, because several here interact with heart drugs.

The list starts with the herbs that have the strongest evidence, then those with earlier or more traditional support, ordered by how widely each is used. Each rating applies to the specific use described, whether cholesterol, blood pressure, heart failure symptoms or vein comfort, rather than to heart health in general. Most trials are short and use particular extracts, so choosing a product like the one studied gives you the best idea of what to expect.

02 The shortlist

The herbs, from best studied to time-honored

How to read the ratings

  • Good clinical evidence
  • Promising clinical evidence
  • Early or mixed evidence
  • Long traditional use

Ratings show how much research backs each herb for this particular concern. Every herb links to its full monograph, with preparations, safety notes, and sources.

  1. 01 Psyllium

    Good clinical evidence

    Plantago ovata

    Psyllium husk is a soluble fiber that EMA accepts, alongside diet, for high cholesterol, and the FDA allows a heart health claim for foods containing it. Pooled data from 28 trials found that about 10 g a day lowered LDL cholesterol by roughly 13 mg/dL, and it may add to the effect of a statin, though no trials have yet measured heart attacks or deaths. Take it with plenty of liquid and half an hour to an hour apart from other medicines.

    Read the psyllium monograph →

  2. 02 Horse Chestnut

    Good clinical evidence

    Aesculus hippocastanum

    Standardized horse chestnut seed extract is the best-studied herb for chronic venous insufficiency, the cause of heavy, aching, swollen legs. A Cochrane review of 17 short trials found less leg pain, swelling and itching than with placebo, and EMA accepts specified extracts as well-established for these symptoms, although larger trials would still help. It is used alongside compression stockings and a check for clots, not instead of them. Raw seeds, bark and leaves are poisonous, and rare liver injury has been reported.

    Read the horse chestnut monograph →

  3. 03 Garlic

    Promising clinical evidence

    Allium sativum

    Garlic is one of the best-loved traditional heart herbs. Meta-analyses suggest supplements can lower total and LDL cholesterol by around 10% in people with raised levels, and can modestly lower blood pressure in people who already have hypertension. Results vary between studies, and a careful Stanford trial found no cholesterol benefit from raw garlic, garlic powder or aged extract. Garlic can increase bleeding, and EMA advises stopping it seven days before surgery.

    Read the garlic monograph →

  4. 04 Hibiscus

    Promising clinical evidence

    Hibiscus sabdariffa

    Hibiscus, or roselle, makes the tart ruby-red tea known as bissap, agua de Jamaica and sorrel, and it is one of the most studied herbs for blood pressure. In a careful six-week US trial, co-funded by a tea company that supplied the hibiscus, three cups a day lowered systolic pressure by about 7 mmHg against 1 mmHg on a placebo drink, and a meta-analysis of 17 trials found a similar average effect, largest in people with raised readings. Trials are short and inconsistent, and Cochrane judged the evidence insufficient. Hibiscus may add to blood pressure medicines and reduced simvastatin levels in a small study, so tell your prescriber.

    Read the hibiscus monograph →

    Evidence review: Hibiscus for Blood Pressure

  5. 05 Green Tea

    Promising clinical evidence

    Camellia sinensis

    Green tea is one of the world’s best-loved drinks and has been tested for cholesterol in dozens of trials. A 2020 meta-analysis of 31 trials found LDL cholesterol about 4.6 mg/dL lower, with no change in HDL or triglycerides, and pooled trials show blood pressure about 1 mmHg lower; NCCIH describes the cholesterol effect as small. Large Japanese cohorts link heavy tea drinking to fewer heart deaths, though no trial has shown fewer heart attacks. Green tea sharply lowers nadolol levels and may reduce atorvastatin, and concentrated extracts have rarely caused serious liver injury.

    Read the green tea monograph →

  6. 06 Black Seed

    Promising clinical evidence

    Nigella sativa

    Black seed (Nigella sativa) is a revered remedy in Islamic and South Asian traditional medicine with a growing body of research. Meta-analyses report LDL cholesterol about 14 mg/dL lower across 17 trials and blood pressure about 3 mmHg lower across 11 trials, though the trials are small and short and blood pressure results vary. It can add to the effects of blood pressure and diabetes medicines, and laboratory data suggest it could raise warfarin levels.

    Read the black seed monograph →

  7. 07 Butcher's Broom

    Promising clinical evidence

    Ruscus aculeatus

    Butcher’s broom root is a traditional European remedy for heavy legs from minor vein problems. A 12-week trial in 166 women with chronic venous insufficiency found less leg swelling and some symptom relief compared with placebo, though EMA wanted more evidence before going beyond traditional use, and many larger reviews test a combination with hesperidin methylchalcone and vitamin C. MSKCC advises people with diabetes not to take it.

    Read the butcher's broom monograph →

  8. 08 Hawthorn

    Early or mixed evidence

    Crataegus monogyna

    Hawthorn leaf and flower is Europe’s classic heart herb, and EMA accepts it as a traditional remedy for nervous palpitations once a doctor has ruled out heart disease. A Cochrane review of small add-on trials found better exercise tolerance and less breathlessness and fatigue in heart failure, though the large SPICE trial found no effect on cardiac events and EMA no longer accepts heart failure as an indication. Because it overlaps with digoxin, it should be used only with a cardiologist’s agreement.

    Read the hawthorn monograph →

  9. 09 Artichoke

    Early or mixed evidence

    Cynara cardunculus var. scolymus

    Artichoke leaf extract is a common ingredient in cholesterol supplements. Meta-analyses of small trials find LDL cholesterol about 10 to 17 mg/dL lower than with placebo after 6 to 12 weeks, but the largest positive trial was run by the extract’s seller and a careful UK trial found no LDL change. It increases bile flow, so avoid it with gallstones or liver disease, and with a daisy-family allergy.

    Read the artichoke monograph →

    Evidence review: Artichoke for Cholesterol

  10. 10 Ginkgo

    Early or mixed evidence

    Ginkgo biloba

    Ginkgo is popular for circulation, cold hands and feet, and leg pain on walking (intermittent claudication), and EMA lists traditional use for heavy legs and cold extremities. Trials have not yet shown a clear benefit, with a 2013 Cochrane review finding no clinically important improvement in walking pain. Ginkgo adds to bleeding risk with anticoagulants and antiplatelet drugs and should be stopped before surgery.

    Read the ginkgo monograph →

  11. 11 Olive Leaf

    Early or mixed evidence

    Olea europaea

    Olive leaf extract, rich in oleuropein, is sold in capsules and liquids for blood pressure. A 2022 meta-analysis of 12 trials found systolic pressure 3.86 mmHg lower, but several key trials were funded by extract makers, a Dutch trial in 77 adults found no effect, and Europe’s medicines agency declined a blood pressure use, accepting only a traditional one for water retention. It may add to blood pressure and diabetes medicines, so check with your prescriber before combining them.

    Read the olive leaf monograph →

  12. 12 Pine Bark

    Early or mixed evidence

    Pinus pinaster

    Pine bark extract, sold mainly as Pycnogenol from French maritime pine, is promoted for circulation and blood pressure. A 2025 meta-analysis of 27 trials found blood pressure about 2 to 3 mmHg lower, but an earlier analysis of seven trials found no effect, a Stanford trial in 130 people found no benefit after 12 weeks, and Cochrane rated the evidence low to very low certainty, with the maker funding 20 of 27 trials. It reduces platelet clumping, so check first if you take blood thinners.

    Read the pine bark monograph →

  13. 13 Moringa

    Early or mixed evidence

    Moringa oleifera

    Moringa is the drumstick tree, and its leaf powder is sold as a superfood. A 2025 meta-analysis of nine small trials found no consistent effect on cholesterol and only a small fall in diastolic pressure that did not hold up, rating the evidence very low certainty, and a 2026 analysis that reported lower blood pressure called its findings preliminary. It may add to blood pressure and diabetes medicines, should be avoided in pregnancy, and some powders have been linked to Salmonella outbreaks.

    Read the moringa monograph →

03 Caution

Using these herbs safely

Most of these herbs are well tolerated at the doses used in trials, and a few sensible precautions help them sit safely alongside heart care. First, know the emergency signs. Call emergency services (911 in the US) for chest pain, pressure or tightness, especially if it spreads to the arm, neck or jaw; severe shortness of breath; fainting or collapse; or signs of stroke, remembered as FAST: face drooping, arm weakness, speech problems, time to call. Stroke symptoms that pass quickly still need urgent help. A swollen, painful calf or sudden swelling of one leg can be a deep vein thrombosis (DVT) and needs same-day medical care. New palpitations, swelling of the ankles or breathlessness on exertion also need a medical check, not an herb.

Keep taking statins, blood pressure medicines and blood thinners as prescribed, and do not stop or reduce them without the prescriber. Bleeding is the most common interaction concern, so it is worth checking with a pharmacist. Garlic and ginkgo both have antiplatelet effects and add to bleeding risk with warfarin, other anticoagulants and antiplatelet drugs; both should be stopped before surgery. Black seed may raise warfarin levels. Hibiscus tea may add to the effect of blood pressure medicines, cut simvastatin levels by about a third in a small study, and has been linked in a single case report to a markedly raised INR in a woman taking warfarin. Green tea sharply lowered blood levels of the beta-blocker nadolol in a small study, green tea extract can reduce levels of atorvastatin, and very large amounts of tea have countered warfarin because of their vitamin K. Hawthorn acts on the same target as digoxin and has been presumed to add to beta-blockers, nitrates and other blood pressure drugs; trials did not show this, but it has not been ruled out. Psyllium can slow the absorption of digoxin and warfarin, so take it at least half an hour to an hour apart from them.

A few herbs are best avoided with heart conditions. Licorice root containing glycyrrhizin raises blood pressure and lowers potassium, can cause dangerous heart rhythms, undermines blood pressure medicines and is particularly hazardous with diuretics and digoxin; the FDA has warned that 2 ounces of black licorice a day for two weeks can cause heart rhythm problems in adults over 40. Deglycyrrhizinated licorice (DGL) removes most of the glycyrrhizin. Yohimbe raises heart rate and blood pressure and has been linked to hypertensive crisis, arrhythmia and heart attack, especially in stimulant stacks. St. John’s wort lowers blood levels of many drugs, including digoxin, ivabradine, warfarin and simvastatin, and the EU contraindicates it with warfarin. Products sold as tejocote (Mexican hawthorn) root have been found to contain toxic yellow oleander.

Medicinal doses of garlic, hawthorn, hibiscus, green tea extract, horse chestnut, butcher’s broom and black seed are not recommended in pregnancy or breastfeeding, and none should be given to children for heart or vein problems. Product form matters too: garlic powder, aged garlic extract and fresh cloves have different chemistry, hawthorn trials used leaf-and-flower extracts rather than berries, hibiscus trials used unsweetened tea or capsules rather than sugary sorrel or agua de Jamaica, concentrated green tea extracts, unlike the drink, have rarely caused serious liver injury, and horse chestnut evidence applies to extracts standardized to escin. Single-herb, clearly labeled products are easier to use safely than unlabeled “circulation” blends, which make it impossible to know which ingredient caused a problem.

04 Questions

Frequently Asked Questions

Psyllium has the most consistent evidence: about 10 g a day of the husk lowered LDL cholesterol by roughly 13 mg/dL in pooled trials, and it may add to the effect of a statin. Garlic and black seed also show encouraging, if smaller or less consistent, effects, and green tea gives a smaller but consistent drop of about 4.6 mg/dL in LDL cholesterol. None has yet been shown to prevent heart attacks, so herbs are a complement to a statin when one is prescribed, not a replacement.

Many people do, and some herbs, such as psyllium, have been studied alongside statins, but always with your prescriber’s knowledge. Statins and blood pressure medicines have been shown to reduce heart attacks, strokes and deaths, so never stop or reduce them in favor of an herb. Your prescriber also needs to know about supplements, because garlic, hawthorn, green tea and others can interact with heart medicines; green tea, for example, sharply lowered levels of the beta-blocker nadolol in a small study.

It may, a little. In a six-week US trial, three cups of hibiscus tea a day lowered systolic pressure by about 7 mmHg compared with about 1 mmHg on a placebo drink, and pooled trials show similar average effects in people with raised readings. But the trials are small and short, and Cochrane judged the evidence insufficient. Hibiscus is not a replacement for blood pressure medicine and may add to its effect, so check your readings and tell your prescriber.

Only with the cardiologist’s knowledge. Hawthorn is generally well tolerated, but it acts on the same target as digoxin, which has a narrow safety margin. A study in eight healthy volunteers found no change in digoxin levels, and large heart failure trials reported no interactions, but that is not enough to rule one out. People with heart failure should not start hawthorn on their own, given a trial signal of earlier worsening.

The clearest risks are licorice root containing glycyrrhizin, which raises blood pressure and lowers potassium; yohimbe, which raises heart rate and blood pressure; and St. John’s wort, which lowers levels of digoxin, warfarin, some statins and other drugs. Anyone on a blood thinner should also check before taking garlic or ginkgo supplements.

It can ease the symptoms. Standardized horse chestnut seed extract reduced leg pain, swelling and itching compared with placebo in short trials of chronic venous insufficiency, and one trial found it comparable to compression stockings for swelling. It will not make varicose veins disappear, and compression remains standard care alongside it. Butcher’s broom is another option with one good trial; our guide to herbs for varicose veins compares them. Sudden swelling of one leg, especially with pain, needs urgent assessment for a blood clot.

05 References

Sources

These references support the claims in this guide. Each herb’s monograph carries its own full source list.

  1. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials

    American Journal of Clinical Nutrition (PubMed 30239559), 2018

    Pooled 28 trials showing that about 10 g of psyllium a day lowers LDL cholesterol by about 0.33 mmol/L, the basis for its good rating.

  2. Horse chestnut seed extract for chronic venous insufficiency

    Cochrane Database of Systematic Reviews (PubMed 23152216), 2012

    Review of 17 trials finding short-term improvements in leg pain, swelling and itch with standardized horse chestnut extract.

  3. Garlic: usefulness and safety

    National Center for Complementary and Integrative Health (NIH), 2025

    Supports the small cholesterol and blood pressure effects of garlic described here, mainly in people with raised readings.

  4. A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers

    Nutrition Reviews (PubMed 34927694), 2022

    Supports the promising rating for hibiscus: across 17 trials, hibiscus lowered systolic blood pressure by about 7 mmHg more than placebo, other teas, or diet combined, and about 10 mmHg against placebo alone, most in people with raised readings, though results varied widely between studies.

  5. Hibiscus sabdariffa L. tea (tisane) lowers blood pressure in prehypertensive and mildly hypertensive adults

    Journal of Nutrition (PubMed 20018807), 2010

    The six-week trial of 65 adults in which three cups of hibiscus tea a day lowered systolic pressure by about 7 mmHg, against about 1 mmHg on a placebo drink; Celestial Seasonings co-funded it and supplied the hibiscus.

  6. Effect of green tea consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials

    Nutrition Journal (PubMed 32434539), 2020

    Supports the some rating for green tea: 31 trials with 3,321 participants found total cholesterol about 4.66 mg/dL and LDL cholesterol about 4.55 mg/dL lower, with no significant change in HDL cholesterol or triglycerides.

  7. Green Tea

    National Center for Complementary and Integrative Health (NIH), 2025

    Describes the small cholesterol effect of green tea, the sharp drop in nadolol levels when taken together, and rare liver injury from concentrated extracts.

  8. The efficacy and safety of Crataegus extract WS 1442 in patients with heart failure: the SPICE trial

    European Journal of Heart Failure (PubMed 19019730), 2008

    The 2,681-patient trial in which hawthorn extract had no effect on time to first cardiac event in heart failure.

  9. Lipid-lowering activity of artichoke extracts: A systematic review and meta-analysis

    Critical Reviews in Food Science and Nutrition (PubMed 28609140), 2018

    Supports the mixed rating for artichoke: nine trials with 702 participants found LDL cholesterol about 14.9 mg/dL lower than controls, though individual trials were small, short, and inconsistent.

  10. Ginkgo biloba for intermittent claudication

    Cochrane Database of Systematic Reviews (PubMed 23744597), 2013

    Found no clinically important benefit of ginkgo over placebo for leg pain on walking.

  11. Heart attack

    NHS, 2026

    Lists heart attack symptoms that need an emergency call, including chest pain spreading to the arm, neck or jaw and severe breathlessness.

  12. Symptoms of a stroke

    NHS

    Explains the FAST signs of stroke and advises urgent help even if symptoms stop.

  13. The effects of olive leaf extract on cardiovascular risk factors in the general adult population: a systematic review and meta-analysis of randomized controlled trials

    Diabetology and Metabolic Syndrome (PubMed 36271405), 2022

    Supports the mixed rating for olive leaf: 12 studies with 819 participants found systolic pressure 3.86 mmHg lower with olive leaf extract, with larger effects in people with high blood pressure.

  14. The effect of olive leaf extract on cardiovascular health markers: a randomized placebo-controlled clinical trial

    European Journal of Nutrition (PubMed 33034707), 2021

    The 77-adult trial in which 500 mg of olive leaf extract a day for eight weeks had no effect on blood pressure, cholesterol or glucose; the lead author worked for the Dutch supplier BioActor.

  15. Assessment report on Olea europaea L., folium

    European Medicines Agency (EMA/HMPC/359236/2016), 2017

    Explains why EMA rejected a cardiovascular indication for olive leaf and accepted only a traditional use for mild water retention.

  16. Pine bark (Pinus spp.) extract for treating chronic disorders

    Cochrane Database of Systematic Reviews (PubMed 32990945), 2020

    Supports the mixed rating for pine bark: 27 trials with 1,641 people gave only low or very low certainty evidence across ten disorders, and the manufacturer funded 20 of the 27 trials.

  17. Does supplementation with pine bark extract improve cardiometabolic risk factors? A systematic review and meta-analysis

    BMC Complementary Medicine and Therapies (PubMed 39987124), 2025

    Pooled 27 trials with 1,685 people and found small falls in systolic and diastolic blood pressure (about 2.3 and 2.6 mmHg) and in LDL cholesterol.

  18. Effect of Pycnogenol on blood pressure: a systematic review and meta-analysis of randomized, double-blind, placebo-controlled studies

    Angiology (PubMed 31763928), 2020

    Seven placebo-controlled trials with 626 people found no significant effect of pine bark extract on blood pressure.

  19. No beneficial effects of pine bark extract on cardiovascular disease risk factors

    Archives of Internal Medicine (PubMed 20876405), 2010

    The Stanford trial in which 200 mg of pine bark extract a day for 12 weeks did not change blood pressure, cholesterol or glucose in 130 people.

  20. Effects of Moringa oleifera Lam. Supplementation on Cardiometabolic Outcomes: A Meta-Analysis of Randomized Controlled Trials with GRADE Assessment

    Nutrients (PubMed 41305552), 2025

    Supports the mixed rating for moringa: nine trials with 649 participants showed no significant effect on most cardiometabolic outcomes and a small diastolic fall that was not robust, all at very low certainty.

  21. Moringa oleifera on hyperglycemia and hypertension in metabolic diseases: Systematic review, exploratory meta-analysis and meta-regression

    Metabolism Open (PubMed 41816507), 2026

    Twenty studies in metabolic disease suggested lower blood pressure and blood sugar with moringa, findings the authors called preliminary because of variation between studies and their quality.

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