Arterial hypertension is classified as systolic blood pressure (SBP) >140 mmHg (millimetre of mercury) or diastolic blood pressure (DBP) >90 mmHg (Chobanian et al., 2003). Prehypertension is a designation used to identify people at high risk of developing hypertension, being classified when SBP is between 120 and 139 mmHg or a DBP between 85 and 89 mmHg (Chobanian et al., 2003). In addition to these, there is a subtype of hypertension known as white-coat hypertension, which refers to the elevation of blood pressure (BP) observed during medical consultations, while values remain normal outside this environment in people who are not under antihypertensive treatment (Kario et al., 2019). According to the American College of Cardiology and the American Heart Association, this condition is characterised by an office BP between 130/80 and 160/100 mmHg, while daytime BP is measured by ambulatory blood pressure monitoring (ABPM) or home BP measurement should be lower than 130/80 mmHg (Whelton et al., 2018).

The global prevalence of hypertension is 1.3 billion adults between the ages of 30 and 79, and approximately 10 million deaths a year may be associated with the hypertensive condition (World Health Organization, 2023, Zhou et al., 2021). Almost half of adults are unaware that they suffer from this chronic disease, and only 21% of adults with hypertension manage to control their condition (Global Health Observatory [GHO], 2023). If appropriate interventions are implemented to increase the rate of hypertension control to 50% worldwide, it is estimated that around 76 million deaths could be avoided between 2023 and 2050 (World Health Organization, 2023). Therefore, successful control of BP in patients with hypertension reduces the occurrence of all causes of cardiovascular mortality, including sudden death, stroke, coronary heart disease, heart failure, atrial fibrillation, arterial disease, and kidney dysfunction (Liu et al., 2024, Mensah et al., 2023).

The medications initially prescribed to control high BP are diuretics, long-acting calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and beta blockers (Joint Committee for Guideline Revision, 2019). A significant percentage (∼70%) of hypertensive patients require more than two medications to reach recommended BP levels, thus increasing the risk of side effects and costs associated with treatment (Guerrero-García and Rubio-Guerra, 2018); and a significant percentage of patients with hypertension (14.7%) (Noubiap et al., 2019) do not respond to conventional treatment (Winner et al., 2024). Therefore, it is important to explore other treatment alternatives (Champaneria et al., 2023).

Phytotherapy is an area of medicine that uses plants to treat diseases or as health-promoting agents (Falzon and Balabanova, 2017). Studies indicate that some plants have antihypertensive properties, species such as garlic (Allium sativum), celery (Apium graveolens), black cumin (Nigella sativa), ginseng (Panax ginseng), and hibiscus (Hibiscus sabdariffa) and are among the most common and used therapeutically to control hypertension (Ajebli and Eddouks, 2020, Jänicke et al., 2003, Verma et al., 2021).

The objective of this systematic review was to gather and synthesise data from experimental trials that explored the most commonly used phytotherapeutic interventions in the treatment of hypertension (A sativum, A graveolens, N sativa, P ginseng, and H sabdariffa), in order to analyse their impact on BP in prehypertensive and hypertensive adults.