Hibiscus

The English names roselle, red sorrel and sour tea refer to the plant Hibiscus sabdariffa, whose red calyces give the tea its colour and tart taste (Egyptian Drug Authority, 2023). The plant is traditionally used as a wild medicinal plant in the Nile region of Egypt and is now grown in many tropical and subtropical countries (Egyptian Drug Authority, 2023). It has been used traditionally as a food, in hot and cold herbal drinks, as a flavouring in the food industry and as a herbal medicine (Da-Costa-Rocha et al., 2014). 

In the Egyptian monograph, the medicinal use of the calyx is based on long-standing traditional use and not on regulatory approval (Egyptian Drug Authority, 2023). In India, roselle is known by regional names such as Lal ambari, Patwa and Gongura. The plant should not be confused with Hibiscus rosa-sinensis, a separate species known as Gudhal or Gurhal in Hindi and Japa in Sanskrit.

Hibiscus sabdariffa is known by the following names in different languages. Regional names and spellings may vary.

• Botanical name: Hibiscus sabdariffa L.
• English: Roselle, sorrel, red sorrel, sour tea, Jamaica sorrel, red tea
• Hindi: Lal ambari, Patwa
• Marathi: Lal ambadi, Tambdi-ambadi
• Telugu: Gongura, Yerra gongura, Yerragogu
• Tamil: Gogu, Pulichai-keerai, Simaikkasuru, Sivappukkasuru
• Malayalam: Polechi, Puli-cheera, Mathipuli, Papuli, Puichchai
• Kannada: Pulichakeere, Kempupundrike, Pulichakire, Pundibija
• Bengali: Chukar
• Assamese: Chukiar, Tengamora
• Manipuri: Silo-sougree
• Sanskrit: Ambasthaki

The calyx contains various compounds, and their amounts vary depending on the plant, growing conditions and preparation (Da-Costa-Rocha et al., 2014). The main compounds are listed below. 

• Delphinidin-3-sambubioside and cyanidin-3-sambubioside: anthocyanin pigments that give the calyx its red colour (Da-Costa-Rocha et al., 2014).
• Protocatechuic acid: a phenolic acid present in the calyx (Da-Costa-Rocha et al., 2014).
• Chlorogenic acid and caffeic acid: phenolic acids present in the calyx (Egyptian Drug Authority, 2023).
• Hibiscus acid and hydroxycitric acid: organic acids that contribute to the sour taste (Da-Costa-Rocha et al., 2014).
• Citric acid, malic acid and tartaric acid: organic acids present in the calyx (Egyptian Drug Authority, 2023).
• Quercetin, rutin, luteolin and kaempferol: flavonoids present in the calyx (Egyptian Drug Authority, 2023).
• Mucilage polysaccharides and pectin: plant fibres that form a gel in water (Egyptian Drug Authority, 2023).
• Vitamin C (ascorbic acid): a vitamin present in the calyx (Egyptian Drug Authority, 2023).

Laboratory and animal studies have described several activities of calyx extracts. Most findings have not been confirmed in well-designed clinical trials (Da-Costa-Rocha et al., 2014).

Laboratory and animal studies have investigated the following potential properties of hibiscus calyx extracts (Da-Costa-Rocha et al., 2014).

• Antioxidant: may help neutralise free radicals in laboratory tests, an activity linked to its anthocyanins and phenolic acids.
• Antibacterial: has shown activity against some bacteria in laboratory studies, but this does not establish effectiveness in treating infections in humans).
• Diuretic: has been associated with increased urine output in experimental studies, which is why caution is needed with kidney conditions and diuretic medicines.

Most of these properties have been investigated mainly through laboratory and animal research, which cannot confirm the same effects in humans. The reviewers of this research state that better-designed clinical trials are needed (Da-Costa-Rocha et al., 2014). Hibiscus extracts may also affect blood pressure and blood glucose, so medical advice is needed before use with regular medicines. Hibiscus is not a substitute for medical treatment or prescribed medicines.

Hibiscus (Hibiscus rosa-sinensis) contains plant compounds studied for antioxidant and anti-inflammatory activity. Research has also explored its potential effects on cardiovascular health, blood sugar, weight management, relaxation, skin and hair health, although evidence for these benefits in humans remains limited. Findings from studies of Hibiscus sabdariffa (roselle) should not automatically be applied to Hibiscus rosa-sinensis, and hibiscus should not replace prescribed medical treatment.

1. May Support Cardiovascular Health

Hibiscus contains polyphenols and anthocyanins that have been studied for their antioxidant effects and possible influence on blood vessel function. Human studies of Hibiscus sabdariffa preparations have reported modest reductions in blood pressure and low-density lipoprotein (LDL) cholesterol, potentially involving mechanisms related to blood vessel relaxation and the regulation of vascular responses. However, these findings cannot be directly generalised to Hibiscus rosa-sinensis, and further research is needed to establish its cardiovascular effects in humans. Hibiscus should not replace prescribed medicines for blood pressure or cholesterol management.

2. May Support Weight Management

Hibiscus extracts have been investigated for their potential effects on fat metabolism and body weight. Experimental studies suggest that certain bioactive compounds may influence processes involved in lipid metabolism. However, evidence from human studies is limited, and it has not been established that Hibiscus rosa-sinensis reduces fat absorption or produces sustained weight loss. Any temporary reduction in body weight due to fluid loss should not be interpreted as fat loss.

3. Has Been Studied for Its Effects on Glucose Metabolism

Hibiscus extracts have been investigated for possible effects on blood glucose regulation and insulin-related processes. Some experimental findings suggest that its bioactive compounds may influence pathways involved in glucose metabolism. However, the evidence is insufficient to establish that Hibiscus rosa-sinensis improves insulin sensitivity or controls blood sugar levels in humans. It should not be used as a substitute for prescribed diabetes medicines.

4. Contains Compounds with Antioxidant Activity

Hibiscus contains various bioactive compounds that have been studied for their antioxidant properties. These compounds may help neutralise free radicals and limit oxidative stress, which can contribute to cellular damage. However, antioxidant activity observed in laboratory studies does not establish that consuming hibiscus strengthens the immune system, increases resistance to infections or prevents illness in humans.

5. Contains Compounds Studied for Anti-inflammatory Activity

Certain hibiscus extracts have demonstrated anti-inflammatory activity in laboratory and animal studies. Their bioactive compounds may influence signalling pathways involved in the body's inflammatory response. These findings provide a basis for further investigation of hibiscus in relation to inflammation. However, clinical evidence is insufficient to establish that Hibiscus rosa-sinensis relieves arthritis-related pain, treats asthma or manages other inflammatory conditions in humans.

6. May Be Associated with Relaxation

Hibiscus tea can be enjoyed as part of a relaxing daily routine, and its aroma and flavour may contribute to the drinking experience. However, there is insufficient clinical evidence to establish that consuming hibiscus has a direct calming effect on the nervous system, reduces anxiety or improves mood. It should not be presented as a treatment for stress or mental health conditions.

7. May Support Skin and Hair Health

Hibiscus contains plant compounds that have been investigated for antioxidant, antimicrobial and other biological activities. These properties have prompted research into its potential topical applications for skin and hair care. However, the available evidence does not establish that hibiscus prevents skin ageing, improves skin elasticity, treats acne or dandruff, prevents hair loss or promotes hair growth in humans. These effects depend on the preparation used and require further clinical investigation.

Hibiscus is used in the ways below. These uses reflect traditional and everyday practices and are not proven treatments (Da-Costa-Rocha et al., 2014).

Preparation of Hibiscus Tea

The dried calyces are steeped in hot water to make hibiscus tea, also called sour tea, which can be served hot or cold (Da-Costa-Rocha et al., 2014). The infusion is red and has a tart taste. It is a herbal infusion, not a tea made from the tea plant. 

Use in Food and Flavouring

Hibiscus calyces are used as a flavouring and colouring in drinks and foods, and the plant has been used traditionally as a food (Da-Costa-Rocha et al., 2014). This is a food-level use and does not give the amounts studied in trials.

Traditional Herbal Medicine and Extracts

In traditional medicine, the calyx is taken as a tea or as a dry extract in capsules or tablets, based on long-standing traditional use rather than regulatory approval (Egyptian Drug Authority, 2023). Persistent symptoms need medical assessment, and herbal use must not delay it. 

Hibiscus is not suitable for everyone. The groups and situations below should seek medical advice before use.

Pregnancy and Breastfeeding

Safety in pregnancy and breastfeeding has not been established, and use during these periods is not recommended (Egyptian Drug Authority, 2023). Avoid hibiscus tea and extracts unless a doctor advises otherwise. 

Children and Teenagers

A safe dose of hibiscus for children and teenagers has not been established. Use it in these age groups only if advised by a paediatrician or a qualified Ayurvedic physician.

Low Blood Pressure and Blood Pressure Medicines

Hibiscus use may lower blood pressure, and combining it with blood pressure medicines may cause blood pressure to fall too low (Egyptian Drug Authority, 2023). Anyone with low blood pressure, or taking these medicines, should consult a doctor before use and have blood pressure checked regularly. 

Diabetes and Blood Glucose

Blood glucose levels may change with hibiscus use, potentially affecting blood glucose control in people taking diabetes medicines (Egyptian Drug Authority, 2023). Anyone with diabetes should monitor blood glucose and consult a doctor before use. 

Planned Surgery

Hibiscus may affect blood glucose control during and after surgery. The cited monograph recommends discontinuing use at least 2 weeks before a planned operation (Egyptian Drug Authority, 2023). Tell the surgeon about any hibiscus product in use and seek advice on when to stop taking it. 

Allergy

People who are hypersensitive to hibiscus, or to other plants of the same family, should not use it (Egyptian Drug Authority, 2023). Stop use if skin rash or itching appears, and seek emergency care for swelling of the face or lips or difficulty breathing. 

Product Identity

Two different plants, Hibiscus sabdariffa and Hibiscus rosa-sinensis, are called hibiscus. Choose a product that states Hibiscus sabdariffa and the calyx as the plant part, and do not use garden flowers for tea.

Long-Term Use

The monograph limits the use of the dry extract to a maximum of 6 weeks (Egyptian Drug Authority, 2023). Consult a doctor before using hibiscus extracts continuously for longer. 

Hibiscus is available as dried calyces for tea and as a dry extract in capsules or tablets. Use only the form and amount advised by your doctor or Ayurvedic physician. The steps for each form are given below.

Preparing Hibiscus Tea

• Place 1.25 to 1.5 g of dried hibiscus calyx in a cup.
• Pour 240 mL of freshly boiled water over the calyx.
• Cover the cup and let the infusion steep for 5 to 10 minutes.
• Strain the tea, and drink it warm or let it cool.

Swallowing Extract Capsules or Tablets

• Read the label to check that the botanical name is Hibiscus sabdariffa and to find the amount of extract in each capsule or tablet.
• Swallow the capsule or tablet whole with water.
• Follow the dosage instructions on the label, and do not use the product for longer than advised by your doctor.

Disclaimer: These steps are for general information. Hibiscus is not a treatment for any disease. Ask a doctor or a qualified Ayurvedic physician before use, especially if you are pregnant, take regular medicines or have a medical condition.

An official dose of hibiscus has not been set for general use. The dosage guidance below is based on the cited monograph and applies to adults (Egyptian Drug Authority, 2023).

Children

The safe dose of hibiscus for children has not been established. Give it to a child only if a paediatrician or a qualified Ayurvedic physician advises, and follow the dose they prescribe.

Teenagers

Dose guidance specific to teenagers is not available. A teenager should use hibiscus only on the advice of a doctor or a qualified Ayurvedic physician.

Adults

• Tea: 1.25 to 1.5 g of dried calyx in 240 mL of boiling water, up to 3 times daily (Egyptian Drug Authority, 2023).
• Dry extract: 300 mg, 3 times daily, for up to 6 weeks (Egyptian Drug Authority, 2023).
• Other extracts and supplements: follow the product label and seek advice from a doctor before use, as preparations and concentrations may vary.

Older Adults

Dose guidance for older adults is also not available. Many older adults take blood pressure medicines or diabetes medicines that may interact with hibiscus, so medical advice is particularly important before use (Egyptian Drug Authority, 2023). 

Disclaimer: These amounts come from a traditional monograph and are not a prescription. Hibiscus is not a treatment for any disease. Ask a doctor or a qualified Ayurvedic physician for the dose that suits you, especially if you are pregnant, take regular medicines or have a medical condition.

A regulatory monograph lists no known undesirable effects, but information is limited, and the effects below may occur (Egyptian Drug Authority, 2023).

Low Blood Pressure

Hibiscus might lower blood pressure, which may cause dizziness or fainting, particularly when used with blood pressure medicines.

Allergic Reactions

Skin rash, itching or swelling can occur in people who are sensitive to hibiscus or to other plants of the same family. Stop use if these symptoms appear.

Changes in Blood Glucose

Hibiscus may affect blood glucose levels. In people who take diabetes medicines, a change in blood glucose may cause shakiness, sweating, hunger or confusion.

Digestive Discomfort

Stomach discomfort or loose stools may occur in some people, particularly with large amounts of the acidic tea. Reports are limited, and the frequency is not known.

When to Seek Medical Help

Stop using hibiscus and contact a doctor if dizziness, fainting, a very slow pulse, shakiness with sweating, or persistent vomiting or diarrhoea occurs. Seek emergency care for swelling of the face or lips or difficulty breathing.

Hibiscus may affect how some medicines work. The potential interactions listed in a regulatory monograph are described below (Egyptian Drug Authority, 2023). 

Blood Pressure Medicines

Blood pressure may fall with hibiscus use. Combining it with medicines that lower blood pressure may cause blood pressure to go too low, so it should be monitored closely under medical guidance (Egyptian Drug Authority, 2023). 

Diabetes Medicines

Hibiscus may affect blood glucose control when used with diabetes medicines. The nature and clinical significance of this potential interaction are not fully established, so blood glucose should be monitored closely (Egyptian Drug Authority, 2023). 

Chloroquine

Hibiscus tea may reduce the effect of chloroquine when the two are used together (Egyptian Drug Authority, 2023). Anyone using chloroquine for malaria should consult a doctor before combining it with hibiscus. 

Simvastatin

The effect of simvastatin may be reduced when hibiscus is also used (Egyptian Drug Authority, 2023). Consult a doctor before using both products. 

Disclaimer: Do not stop or change any prescribed medicine without advice from your doctor. Tell your doctor and pharmacist about every herbal product you use, including hibiscus.

Storage of Hibiscus

Proper storage helps maintain the quality and safety of hibiscus products. The points below apply to dried calyces, tea, capsules and tablets.

• Store dried calyces in a tightly closed container in a cool, dry place away from direct sunlight.
• Keep the product away from moisture, and discard it if it smells musty or shows mould.
• Use brewed tea on the same day, or keep it in a covered container in the refrigerator.
• Do not use any product after its expiry date.
• Keep all products out of the reach of children.
• Follow the storage instructions printed on the label of any capsule or tablet.

• Hibiscus (Hibiscus sabdariffa) is a plant whose dried red calyces are used for hibiscus tea and herbal preparations, and the name Gudhal usually refers to a different species (Egyptian Drug Authority, 2023).
• Laboratory and animal studies describe antioxidant, antibacterial and diuretic activity, but well-designed clinical trials are needed to establish these effects in humans (Da-Costa-Rocha et al., 2014).
• Blood pressure might fall and blood glucose may change with use, so potential interactions with blood pressure medicines, diabetes medicines, chloroquine and simvastatin require caution (Egyptian Drug Authority, 2023).
• Use during pregnancy and breastfeeding is not recommended, and the cited monograph advises stopping use at least 2 weeks before planned surgery (Egyptian Drug Authority, 2023).
• This herb is not a treatment for any disease, and a doctor should be consulted before use, especially if you have a medical condition or take regular medicines.