Excellent, it lowers the pressure (tested on my 84-year-old mother) when it is due to cardiovascular issues (because my mother has 2 sources of pressure = mainly gastrointestinal problems, and less problems due to age-related wear in the cardiovascular system).
I open the capsule, pour it into a little juice, e.g., peach (which changes its color to red), and administer it.
In fact, together with the product Swanson Naringin 60 capsules, it works even better (when there is also a high hematocrit, which Naringin lowers within 15 days to 1 month).
Hibiscus has no side effects, but Naringin (= produced from the peel of grapefruit) can interact with medications, so a little caution is needed in administration.