High blood pressure, also called hypertension, develops when blood consistently pushes against the blood-vessel walls with excessive force. It usually requires regular monitoring, healthy lifestyle changes and, for many people, prescribed medication. No herb, tea or dietary supplement has been shown to lower blood pressure as reliably as approved hypertension medicines.
Some herbs have been studied for possible cardiovascular effects. However, the evidence varies considerably. A few may produce small changes in blood pressure, while others have little reliable evidence or carry important medication-interaction risks.
Herbs should therefore be considered optional additions to an evidence-based health plan not replacements for medical assessment or prescribed treatment.
Can herbs lower blood pressure?
Research suggests that garlic and roselle, commonly called hibiscus, may produce small blood-pressure reductions in some people with hypertension. However, the available evidence is limited, and the effects are generally modest. NCCIH states that no dietary supplement has demonstrated effects comparable to medicines used to treat hypertension.
A product labelled “natural” is not automatically safe. Herbal products may:
- Interact with blood-pressure or heart medicines
- Increase the risk of bleeding
- Lower blood pressure excessively
- Affect blood glucose
- Cause digestive or allergic reactions
- Contain variable concentrations of active ingredients
Anyone taking regular medication should discuss herbal supplements with a doctor or pharmacist before beginning them.
1. Garlic
Garlic is widely used as a culinary ingredient and is also sold as powders, oils and concentrated supplements.
Limited evidence suggests that garlic supplements may reduce blood pressure by a small amount in people who already have hypertension. However, many studies have been small, preliminary or of limited quality, so garlic should not be considered a substitute for standard treatment.
How to use garlic
Garlic may be included in ordinary meals such as:
- Vegetable dishes
- Soups
- Lentils and beans
- Fish or chicken dishes
- Homemade sauces and dressings
There is no need to swallow a raw garlic clove every day. Raw garlic may cause stronger digestive side effects than cooked garlic for some people.
Safety considerations
Garlic supplements may increase bleeding risk, especially in people taking aspirin, warfarin or other anticoagulant or antiplatelet medicines. Common side effects include abdominal discomfort, nausea, gas and strong breath or body odour. People preparing for surgery should tell their healthcare team about garlic supplements.
Evidence summary: Some evidence of a small blood-pressure effect, but not strong enough to replace medical treatment.
2. Hibiscus
Hibiscus tea is commonly prepared from the dried calyces of Hibiscus sabdariffa, also known as roselle. It produces a tart, deep-red drink.
Research suggests that hibiscus may help reduce blood pressure modestly in some people with hypertension. However, the evidence remains limited, and the expected effect is small.
How to use hibiscus
Hibiscus can be enjoyed as:
- An unsweetened hot herbal tea
- A chilled infusion
- A beverage flavoured with a small amount of lemon or mint
Avoid adding large amounts of sugar, particularly when the goal is cardiovascular or metabolic health.
Safety considerations
Hibiscus tea may add to the effects of blood-pressure-lowering medication and could potentially contribute to low blood pressure in susceptible people. Those taking hypertension medicines, diabetes medicines or multiple prescriptions should consult a healthcare professional before using concentrated hibiscus products regularly.
Pregnant or breastfeeding individuals should also seek professional advice before using medicinal amounts of herbal products.
Evidence summary: Promising but limited evidence for a small supportive effect.
3. Ginger
Ginger is commonly used in cooking and beverages. It has been studied more extensively for nausea and menstrual discomfort than for hypertension.
Although ginger is sometimes promoted as a herb that relaxes blood vessels or lowers blood pressure, current evidence does not establish it as a reliable hypertension treatment. NCCIH does not list blood-pressure control among ginger’s clearly supported uses.
How to use ginger
Small food-level amounts may be added to:
- Curries and stir-fries
- Soups
- Vegetable dishes
- Unsweetened tea
- Smoothies
Safety considerations
Oral ginger can cause abdominal discomfort, heartburn, diarrhoea and irritation of the mouth or throat. Herbal products may also interact with medicines, so concentrated ginger supplements should be discussed with a healthcare provider.
Evidence summary: Suitable as a flavouring, but not proven to treat high blood pressure.
4. Hawthorn
Hawthorn has a long history of traditional use for heart-related concerns. It is sold as capsules, liquid extracts and tinctures.
However, hawthorn should not be casually recommended for people with hypertension or heart disease. Evidence for cardiovascular benefit is uncertain, and one study raised concern that a particular hawthorn preparation might have contributed to earlier heart-failure progression, possibly through interaction with patients’ medicines.
Safety considerations
Reported side effects include:
- Dizziness
- Nausea
- Vomiting
- Diarrhoea
- Muscle pain
Hawthorn may interact with heart or blood-pressure medicines. Its safety beyond approximately 16 weeks has not been established in research studies.
Anyone with heart failure, chest pain, irregular heartbeat or prescribed cardiovascular medication should not use hawthorn without medical supervision.
Evidence summary: Insufficient evidence and meaningful interaction concerns; professional supervision is necessary.
5. Cinnamon
Cinnamon is a popular spice commonly used in oatmeal, fruit dishes, tea and baked foods.
Despite frequent claims about cinnamon supporting blood sugar, circulation or blood pressure, research does not clearly support its use for any particular health condition. It should therefore be treated as a flavouring rather than a blood-pressure remedy.
How to use cinnamon
Food-level amounts may be sprinkled on:
- Oatmeal
- Plain yogurt
- Fruit
- Unsweetened drinks
- Whole-grain dishes
Safety considerations
Cinnamon is likely safe in normal culinary amounts. Larger amounts taken for long periods may cause digestive problems or allergic reactions.
Cassia cinnamon can contain coumarin, a naturally occurring compound that may be problematic for people with liver disease when consumed in substantial amounts over time. Product labels may not always clearly identify the cinnamon species used.
Never swallow dry cinnamon powder as part of an online challenge because serious respiratory harm can occur.
Evidence summary: Fine as a spice, but not supported as a hypertension treatment.
6. Tulsi, or Holy Basil
Tulsi, also called holy basil, is traditionally used in Ayurvedic practices and is commonly consumed as tea.
Human studies have explored tulsi for several metabolic, stress-related and general-health outcomes. However, the available evidence does not establish tulsi as a proven treatment for hypertension. A systematic review identified a range of small human studies, but stronger, hypertension-specific clinical trials are still needed before dependable conclusions can be drawn. This is a cautious interpretation of the available research rather than proof of effectiveness.
How to use tulsi
People who already tolerate it may enjoy tulsi as an occasional unsweetened herbal tea. It should not be marketed as a guaranteed way to normalise blood pressure.
Safety considerations
There is no universally established medicinal dose for blood-pressure treatment. Concentrated extracts may behave differently from ordinary tea and may interact with medicines or health conditions.
People who are pregnant, breastfeeding, preparing for surgery or taking medicines for blood pressure, diabetes or blood clotting should seek professional guidance before using tulsi supplements.
Evidence summary: Traditional use and preliminary research, but insufficient evidence for hypertension treatment.
Herbs that may raise blood pressure
Not every herbal product supports blood-pressure control. Some supplements can increase blood pressure or interfere with medicines.
NCCIH specifically warns that products containing bitter orange, ephedra, ginseng or liquorice root may raise blood pressure or interact harmfully with treatment.
Liquorice root containing glycyrrhizin may cause serious effects, including irregular heartbeat, particularly in people with hypertension or heart or kidney conditions.
Always check the ingredient list of herbal teas, energy products and mixed supplements.
What works better than herbal supplements?
For most people, blood-pressure management should focus on proven measures.
Follow the DASH eating pattern
The DASH eating plan emphasises vegetables, fruits, whole grains, beans, nuts, fish, poultry, low-fat dairy and healthy oils while limiting sodium, saturated fat and sweets. It is designed to support a heart-healthy eating pattern without requiring special products.
Reduce excess sodium
The American Heart Association advises people with high blood pressure to limit sodium to less than 2,300 milligrams daily and ideally move toward 1,500 milligrams when appropriate. Individual recommendations may differ, particularly for people with kidney, heart or electrolyte problems.
Take prescribed medicines correctly
There are no special herbs, vitamins or drinks that can replace prescription medication and lifestyle changes. Do not stop or reduce a blood-pressure medicine without discussing it with the prescribing healthcare professional.
Other important habits include regular physical activity, maintaining an appropriate body weight, limiting alcohol, avoiding tobacco, obtaining sufficient sleep and monitoring blood pressure correctly.
When high blood pressure is an emergency
A reading above 180/120 mm Hg requires immediate attention.
Wait at least one minute and repeat the measurement. When the reading remains above 180/120 and there is chest pain, shortness of breath, back pain, numbness, weakness, vision changes or difficulty speaking, emergency medical help is required immediately.
Do not attempt to manage a possible hypertensive emergency with garlic, tea or any other home remedy.
Final thoughts
Garlic and hibiscus have the most relevant evidence among the six herbs discussed, but their possible effects are small and should be viewed only as supportive. Ginger, cinnamon and tulsi have not been proven to control hypertension. Hawthorn has important safety and interaction concerns and should not be used without professional supervision.
The safest approach is to use ordinary herbs and spices to flavour a balanced, lower-sodium diet while following a personalised treatment plan developed with a qualified healthcare professional.
Medical disclaimer
This article is for general educational purposes and does not provide diagnosis or personalised medical treatment. High blood pressure can cause serious complications and should be assessed by a qualified healthcare professional. Never replace or discontinue prescribed medication with an herb or supplement without medical guidance.
