Originally from Angola, Hibiscus is now cultivated throughout tropical and subtropical regions, especially in Sudan, Egypt, Thailand, Mexico, and China.
In Egypt and Sudan, Hibiscus is used to help maintain a normal body temperature, support heart health, and encourage fluid balance.* 
North Africans have used hibiscus internally for supporting upper respiratory health including the throat throat and also use it topically to support skin health.
In Europe, hibiscus has been employed to support upper respiratory health, alleviate occasional constipation, and promote proper circulation.* It is commonly used in combination with lemon balm and St John’s Wort for restlessness and occasional difficulty falling asleep.*
Hibiscus is traditionally used for supporting normal blood pressure maintenance in Iran — a use that has been validated in several recent studies.
Phytochemistry
Approximately 15-30 percent of the hibiscus plant is made up of plant acids, including citric acid, malic acid, tartaric acid and allo-hydroxycitric acid lactone — i.e. hibiscus acid, which is unique to hibiscus.
Other chemical constituents are many; however, some of the most important include alkaloids, anthocyanins, and quercetin.
Indications
Scientific interest in hibiscus has grown in the last several years, thanks to a small burst of published research studies — especially in regards to cholesterol and blood pressure maintenance.
Cholesterol Maintenance 
In 2007, a one-month clinical trial tested the effects of hibiscus extract on cholesterol levels. A total of 42 subjects were randomized to three groups for the study. Group 1 received one 500-mg capsule 3x daily (1,500 mg/day), Group 2 received two capsules 3x daily (3,000 mg/day), and Group 3 received three capsules 3x daily (4,500 mg/day). Interestingly, by the fourth week, participants in both Groups 1 and 2, but not Group 3, experienced a cholesterol maintenance effect. The optimum dose was 1,000 mg taken 3x daily.
In 2009, another trial studied hibiscus’s ability to support cholesterol maintenance, this time in people concerned with healthy blood sugar levels. Sixty subjects, mostly women, were given either one cup of hibiscus tea or black tea twice per day. After one month, hibiscus was able to help maintain total, LDL, and HDL cholesterol levels — as well as triglycerides — already within a healthy range.* Black tea, on the other hand, only impacted HDL levels.
 
A larger trial, in 222 adults, was published on hibiscus in 2010. The subjects — about a third of whom had metabolic challenges — were randomly assigned to one of three groups: a healthy diet, hibiscus, or a healthy diet plus hibiscus. Those with metabolic challenges experienced several benefits from hibiscus, including cholesterol maintenance. Similar effects on supporting normal blood sugar were also noted.*
 
Blood Pressure Maintenance
In 2007, a randomized, controlled, double-blind study researched Hibiscus’s blood pressure maintenance capacity. Participants received either a dried powdered hibiscus extract, containing a total of 250 mg anthocyanins, or an alternate intervention. Hibiscus extract was able to maintain blood pressure levels already within a healthy range, but importantly, it did not alter blood potassium levels, nor did it affect salt-water balance.*
 
A trial comparing Hibiscus to black tea among people seeking to support healthy blood sugar levels was published in 2009. Subjects were randomly assigned to drink one cup of hibiscus tea or black tea two times per day for one month. Hibiscus tea demonstrated a maintenance effect on systolic (but not diastolic) blood pressure, while black tea did not.*
 
A Cochrane review of Hibiscus’s effects on blood pressure published in 2010 resulted in five articles. The reviewers included randomized controlled trials of three to 12 weeks in duration that compared hibiscus to either placebo or no intervention at all. All five of these studies found hibiscus had a blood pressure maintenance effect.
 
Safety and Dosage
The safety profile of Hibiscus is excellent, with no proven adverse reactions. 
It is difficult to clarify dosing recommendations when different products are used in different studies. However, positive studies used the following dosages:
For cholesterol maintenance: 1,000 mg dried herb 3x daily, one cup of hibiscus tea 2x daily, or 100 mg of standardized extract 2x daily.
For blood pressure maintenance: One cup of hibiscus tea 2x daily or dried powdered hibiscus extract providing 250 mg anthocyanins per day.
 
Conclusion
 
It is exciting to see the use of this simple, safe plant evolve from home beverage to medicinal utilization for such common health support such as blood pressure and cholesterol maintenance.
Hibiscus helps maintain cholesterol levels that are already within a healthy range.*
Hibiscus helps maintain blood pressure levels that are already within a healthy range.*
 
(this is research and should not be consumed or taken as a medical suplement with out speaking 1st with your dr.)