Hibiscus Tea: Benefits, Blood Pressure, Recipe & Side Effects

Dr. Josh Axe · Free quiz

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Drop a spoonful of dried hibiscus calyces into a cup of hot water and the water turns a deep ruby red. That color comes from anthocyanins, the same family of pigments that colors blueberries.101 The calyces are the fleshy sepals that cup each flower of roselle, Hibiscus sabdariffa, a plant native to tropical Africa.11

People brew them into hot and cold drinks around the world, and decoctions and infusions of the calyces are used for high blood pressure in at least 10 countries.1213 The names change along the way: karkade and bissap in West and North Africa, zobo in Nigeria, sour tea in Iran and flor de Jamaica in Mexico.141516411

My protocol's 7-day meal plan includes 2 to 3 cups of hibiscus tea a day, and its supplement plan lists hibiscus as a traditional heart tea.1 The reason is a placebo-controlled trial the protocol cites, in which three cups a day lowered systolic pressure in adults with prehypertension or mild high blood pressure; the blood pressure section below has the numbers.3

Did you know?

• Hibiscus is one of the herbs people with high blood pressure reach for most. In a review of 37 surveys from 21 countries, garlic, hibiscus and olive were the most commonly used of 71 herbs.17

• In a lab comparison of 33 herbal teas, hibiscus was one of three that stood out for GABA, an amino acid your brain also uses as a chemical messenger, and none of the 33 contained caffeine.18

• When Nigerian researchers compared hibiscus with a blood pressure drug, they chose the dose of their hibiscus infusion because it gave about the same color as zobo, the hibiscus drink brewed locally.19

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What is hibiscus tea?

Roselle is grown for food as well as drink: the calyces go into hot and cold beverages, flavorings and herbal medicine.20 Hibiscus is a large plant genus, and the research on this page was done on Hibiscus sabdariffa, so look for that name, or roselle, on the label.

The raw calyx is a food in its own right. USDA lists 100 grams of raw roselle at 49 calories, with 215 milligrams of calcium, 1.48 milligrams of iron and 12 milligrams of vitamin C.21 Brewing pulls a different set of compounds into the cup, as the nutrition section below shows.

A short history of hibiscus tea

Traditional medicine uses the calyx for high blood pressure, liver disease and fever,12 and in Mexico, hibiscus drinks are taken as a diuretic and for digestive complaints, liver disease, fever, high cholesterol and high blood pressure.22 Healers in Senegal used it for high blood pressure too,23 and in Nigeria, where the drink is called zobo, it has long been a traditional remedy for the same problem.24

Researchers have been testing that tradition in trials since at least 1999, and one of its oldest uses lines up with what they measured.25 Traditional healers used hibiscus as a diuretic, and trials later measured more sodium leaving the body in the urine of people who took hibiscus drinks or capsules.2627

Jordan Rubin and I cite this verse in The Biblio Diet as a reminder that God provides herbs for our good: "He causeth the grass to grow for the cattle, and herb for the service of man: that he may bring forth food out of the earth" (Psalm 104:14).2829 Hibiscus has served people that way for generations.

Hibiscus tea nutrition facts

Values from USDA FoodData Central, FDC ID 171946 (beverages, tea, hibiscus, brewed; SR Legacy), per 8-fluid-ounce cup (237 grams), USDA's own serving. Per-cup amounts are calculated from the per-100-gram values; % Daily Value uses FDA label reference values.2

A cup gives you nearly half a day's manganese for no calories, with little else in the way of vitamins or minerals.2 USDA lists no vitamin C in the brewed tea, even though the raw calyx carries 12 milligrams per 100 grams.221

The compounds behind the color

Hibiscus tea's main anthocyanin, delphinidin-3-sambubioside, is the major pigment in the brewed infusion as well as in extracts.10 A hibiscus drink also carries organic acids, led by hibiscus acid, and in one human study they far outweighed the anthocyanins and other polyphenols.30

Those compounds show up in measures of your body's antioxidant defenses. In 8 healthy adults who each drank a hibiscus extract and plain water on different days, the extract raised the blood's antioxidant power and lowered urinary malondialdehyde, a marker of oxidative damage.31 In a human study, a single 10-gram dose of hibiscus extract lowered MCP-1, a signal that draws inflammatory cells, without changing other inflammation markers.32 And in a 6-month placebo-controlled study in which 39 healthy adults each tried both drinks, 200 milliliters (about 7 ounces) of a roselle drink a day raised their antioxidant enzymes and lowered their blood pressure from where they started.33

What is hibiscus tea good for?

How does hibiscus tea work in your body?

Researchers have traced several ways hibiscus may lower blood pressure, and each step comes from a different kind of study: lab tests, rat studies and human trials. Here's how they fit together:

Which step matters most is still being worked out: in 31 people with metabolic syndrome, researchers judged the antioxidant, anti-inflammatory and vessel-lining effects more important than the diuretic and ACE effects.43

Hibiscus tea benefits, ranked by evidence

Blood pressure leads this list because it has the deepest human research on this page and it's why hibiscus tea is in my protocol.1

Does hibiscus tea lower blood pressure?

High blood pressure is something you want to act on. My High Blood Pressure Protocol names insulin resistance as the #1 driver and chronic stress as the fuel line,1 and as I've said on my show, reducing stress is typically the single biggest factor in bringing it down.49 The protocol starts by calming the nervous system for two weeks, then refills the potassium and magnesium your vessels relax on.1 Hibiscus tea is one of its daily drinks, along with water, green or herbal tea, and beetroot juice a few times a week, and its last step keeps aged garlic or hibiscus going for ongoing support.1 For the food side, see the high blood pressure diet and these foods that lower blood pressure.

The brewed-tea trial

The trial my protocol cites tested the tea itself. Researchers at Tufts University gave 65 adults aged 30 to 70 with prehypertension or mild high blood pressure, none taking blood pressure medicine, three 240-milliliter (8-ounce) cups a day of hibiscus tea or a placebo drink for 6 weeks; neither the people nor the researchers knew who got what.3 Each cup was brewed from 1.25 grams of dried calyces steeped in 240 milliliters of boiled water.13

Systolic pressure fell 7.2 points with hibiscus, against 1.3 with placebo. Diastolic pressure, the bottom number, fell 3.1 points against 0.5, a difference too small to rule out chance, and people who started with higher systolic pressure saw bigger drops.3

What the pooled trials show

Four reviews that pooled the randomized trials point the same way. Systolic pressure fell 7.58 points across 5 trials with 390 people in a 2015 review.5 In a 2022 review, it fell 7.10 points against placebo, other teas or a diet, and 10.05 points in the placebo-controlled trials alone.6 Another 2022 review, of 13 trials with 1,205 people in all, found 6.67 points against placebo, with diastolic pressure down 4.35,7 and a 2020 review of 7 trials with 362 people found 4.71 points, with diastolic pressure down 4.08.4 Drops were larger where pressure started higher,56 and one review found no significant drop in people whose high blood pressure came with metabolic syndrome.7

The newest review, an umbrella review of 26 trials with 1,797 people, rated a drop of more than 10 points moderately credible, especially in adults over 50 and in trials lasting longer than 4 weeks.38

How fast it works

In trials, the drop came within weeks. In a 1999 study in Iran that set out to test the public belief in sour tea, 54 adults with moderate high blood pressure were randomly assigned to the tea or a control group, and in the tea group, systolic pressure was 11.2% lower after 12 days than at the start; 3 days after the tea stopped, it had risen 7.9%.25 In a 4-week study in Egypt of 50 adults with moderate high blood pressure and 50 with normal pressure, which wasn't randomized, systolic pressure fell 19.6% and 10%, then returned to where it started over the 4 weeks after people stopped taking roselle.50 On heart tracings, 10 of the 14 patients who started with a thickened heart wall no longer showed it after 4 weeks of roselle, and it returned in 6 of them after they stopped.50 In both studies the effect faded once people stopped, so hibiscus works as a daily habit.

Hibiscus tea vs. blood pressure drugs {#vs-drugs}

Trials have also tested hibiscus head to head with blood pressure medicine, and the table gives the daily amount each one used:2619402714

Two newer trials, of 70 and 72 adults with high blood pressure and kidney disease over about 3 months, gave a hibiscus extract alongside valsartan, a blood pressure drug, under medical care and compared it with valsartan plus hydrochlorothiazide. The hibiscus combination improved cholesterol in both and kidney markers in one, while valsartan with hydrochlorothiazide lowered pressure more in that same trial.5152 Across the pooled analyses, hibiscus and the drugs it was compared with lowered blood pressure by similar amounts, with no significant difference between them.6738

How much hibiscus tea should you drink a day?

Because hibiscus tea has no caffeine, you can drink it at any time of day, including the evening.218 The trials gave it as separate servings through the day, so spread your cups out if you like.3 Track how it's working the way my protocol does, with a home blood pressure cuff and a reading each morning and evening.1 If you'd rather not brew tea, my protocol's supplement plan gives hibiscus extract, taken as the label directs, as the alternative.1

How to make hibiscus tea

1. Measure 1.25 to 2 grams of dried calyces for each 8-ounce cup; a small kitchen scale makes it easy.1355

2. Pour boiling water over them, the way those trials brewed their tea.1355

3. Steep about 10 minutes, the time one human study used, until the tea turns deep red.34

4. Strain and drink it hot, or cool it and pour it over ice.

Choose whole dried calyces sold loose. On my show, I've encouraged people to drink lots of tea, including herbal tea, and to choose loose-leaf tea or tea whose bags are made without plastic.56 In a lab test, a single plastic tea bag steeped at 95°C (203°F) released about 11.6 billion microplastic and 3.1 billion nanoplastic particles into one cup.57 Loose calyces skip the bag entirely; read more about plastic in tea bags.

How to make agua de Jamaica

In Mexico, where the calyces are called flor de Jamaica, the drink is served cold as agua de Jamaica.1112 This version keeps the strength of a sour tea trial, about 2 grams of calyces per cup:55

1. Steep 8 grams of dried calyces in 4 cups (about 1 liter) of boiling water for 10 minutes, then strain.

2. Sweeten it lightly, if at all, by stirring a teaspoon or two of raw honey into the warm tea.

3. Add the juice of a lime, chill and serve over ice.

If you sweeten it, use raw honey or Manuka honey in place of cane sugar, and keep it within the 1 teaspoon to 1 tablespoon of raw local honey I recommend for the whole day.58 For another chilled drink, try this watermelon agua fresca, and see more healthy drinks.

Hibiscus tea side effects and who should skip it

As I wrote in my Top 50 Healing Herbs guide, herbs are real medicine, which is exactly why they can interact with medications.60 Hibiscus is a good example: the same effects that lower your blood pressure are the reason to bring your prescriber in if you take medicine for it.

Hibiscus lowered pressure in people whose pressure was normal too, by 10% in the Egyptian study, so if your blood pressure already runs low, check your readings before making it a daily habit; see low blood pressure.50 In the umbrella review of 26 trials, hibiscus came with a small rise in the liver enzyme AST that the authors judged clinically insignificant, with no rise in side effects.38

The bottom line

Hibiscus tea: frequently asked questions

References

1. Axe J. The High Blood Pressure Protocol. DrAxe.com protocol. 2026 (p. 7, "The Eight Drivers": insulin resistance and hyperinsulinemia "THE #1 DRIVER", chronic stress and sympathetic overdrive "THE FUEL LINE"; p. 9, "The Reset Roadmap": "You don't manage high blood pressure — you remove what's driving it. Relax the vessels, refill the minerals, and the body remembers how to hold a healthy pressure."; Step 1, Calm: a home blood-pressure cuff with a morning and evening reading, and "If on medication, keep taking it exactly as prescribed"; Step 5, Sustain: "Aged garlic or hibiscus for ongoing support"; p. 15, foods that heal: blueberries' anthocyanin polyphenols; p. 16, 7-day meal plan, Daily drinks: "Hibiscus tea, 2–3 cups (lowers systolic pressure in trials)"; p. 17, tiered supplement plan: hibiscus, "Hibiscus extract · Per label, or 2–3 cups tea", "A traditional heart tea shown to lower systolic pressure in prehypertensive and mildly hypertensive adults"; Troubleshooting & FAQ: "Never stop or change a blood-pressure medication on your own").
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Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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