Hibiscus tea may help lower blood pressure, according to clinical research, although evidence is not strong enough to recommend it as a replacement for established hypertension treatments.
The drink is made from Hibiscus sabdariffa, a flowering plant commonly known as roselle. It is consumed in different parts of the world under names including bissap in West Africa, flor de jamaica in Mexico and soobolo in Ghana.
The tea has a tart taste, a deep red colour and can be served hot or cold. It contains plant compounds, including anthocyanins and other polyphenols, that have antioxidant properties.
What research says about blood pressure
A 2021 systematic review and meta-analysis published in the Journal of Human Hypertension examined 13 randomised controlled trials involving 1,205 participants with mild-to-moderate hypertension or related metabolic conditions.
The researchers found that hibiscus preparations reduced systolic blood pressure, the pressure in the arteries when the heart contracts, by an average of about 6.7 millimetres of mercury compared with a placebo. Diastolic blood pressure, measured when the heart relaxes between beats, also fell by an average of about 4.4 mmHg.
However, the findings varied across studies, and the researchers said further trials were needed to establish the effectiveness of hibiscus and identify the people most likely to benefit.
The US National Center for Complementary and Integrative Health also lists roselle among foods and supplements that may help reduce blood pressure, while cautioning that the evidence remains limited and the effects are small compared with those of established hypertension medicines.
High blood pressure that remains uncontrolled increases the risk of heart disease, stroke and other complications. People diagnosed with hypertension should continue following their prescribed treatment plan rather than relying on herbal tea alone.
Antioxidants and cholesterol
Hibiscus contains antioxidants, including anthocyanins, which are plant pigments responsible for much of its red colour. Antioxidants help protect cells against oxidative stress, a process involving unstable molecules that can damage cells.
Laboratory research and some human studies have investigated whether these compounds could also improve cardiovascular health by affecting blood pressure and blood fats.
A systematic review published in Nutrition Reviews in 2022 found that hibiscus consumption was associated with a reduction in low-density lipoprotein (LDL), often called bad cholesterol, compared with placebo or other teas. However, the evidence for changes in other blood fats was less consistent.
These findings do not establish hibiscus tea as a treatment for high cholesterol or diabetes. More research is needed to determine the size and reliability of its effects, including whether the changes translate into fewer cardiovascular complications.
Does hibiscus tea help with weight loss?
Hibiscus is sometimes promoted as a weight-loss drink, partly because of claims that it acts as a diuretic, increasing the amount of water excreted through urine.
However, losing water is not the same as losing body fat. Any temporary change in weight caused by fluid loss does not establish that hibiscus tea produces sustained weight reduction.
Some laboratory and animal studies have examined the plant’s effects on fat metabolism and inflammation, but such findings cannot automatically be applied to people. There is insufficient clinical evidence to recommend hibiscus tea as a proven weight-loss treatment.
Safety and possible interactions
Hibiscus tea is consumed as a beverage in many countries, but its safety can depend on the amount consumed, the preparation and a person’s health or medication use.
Because hibiscus may lower blood pressure, people taking blood pressure medicines should consult a healthcare professional before using it regularly for that purpose. Interactions between hibiscus preparations and some medicines remain insufficiently studied.
People who are pregnant or trying to conceive should seek medical advice before using hibiscus in medicinal amounts. Evidence on its safety during pregnancy is limited, and claims that it reliably induces menstruation are not supported by sufficient human research.
Anyone concerned about high blood pressure should have it measured and seek appropriate medical advice. Hibiscus tea may be an addition to a balanced diet, but it should not replace medical assessment, prescribed medicines or other recommended measures for controlling hypertension.
