Why One Herb Doesn’t Fit Every Case of High Blood Pressure
Written by N. Streawbridge| 29 April 2026
How Clinical Herbal Medicine Approaches Hypertension
Two people can have exactly the same blood-pressure reading. But the physiology producing that reading may be very different. That distinction matters. It is one of the reasons clinical herbal medicine does not begin with the question:
“What herb lowers blood pressure?”
Instead, we ask a broader question:
“What may be contributing to elevated blood pressure in this particular person?”
Because hypertension is not one single physiological problem — and understanding the pattern behind it can change the way we formulate.
Blood pressure is a measurement, not a mechanism
Blood pressure tells us about the force exerted by circulating blood against the walls of the arteries. It is an extremely important measurement. Persistently elevated blood pressure increases the risk of cardiovascular disease, stroke, kidney disease and other forms of organ damage. Bur the reading itself does not tell us why the pressure is elevated.
Modern cardiovascular physiology recognises hypertension as the product of complex interactions between the kidneys, cardiovascular system, nervous system, hormonal signalling, blood vessels, metabolism, genetics, behaviour and environment.
In most people, hypertension is classified as primary or essential hypertension. This means there is no single identifiable disease responsible for it. Rather, several regulatory systems may gradually become dysregulated and contribute to the development of persistent high blood pressure.
In other people there is an identifiable secondary cause, such as renal disease, primary aldosteronism, obstructive sleep apnoea, certain endocrine disorders or medicines that raise blood pressure. These require appropriate medical investigation and treatment.
So when we talk about the “drivers” of hypertension in clinical herbal medicine, we are usually talking about the physiological processes contributing to the individual picture — not claiming that every case has one hidden underlying cause waiting to be discovered.
The same reading can come from different physiology
Consider several very different possibilities.
1. Kidney and fluid regulation
The kidneys are central to long-term blood-pressure regulation. They regulate sodium, water balance, circulating volume and several hormonal systems involved in vascular tone and blood pressure.
In some people, altered sodium handling, salt sensitivity, renal dysfunction or activation of the renin–angiotensin–aldosterone system may form an important part of the hypertensive picture. Contemporary hypertension guidelines specifically recognise renal and neurohormonal mechanisms as central contributors to blood-pressure dysregulation.
That is a very different physiological situation from hypertension dominated primarily by increased vascular resistance.
2. Increased vascular resistance
Blood pressure is strongly influenced by how constricted or relaxed the arterial system is.
The endothelium — the specialised cellular lining of our blood vessels — is actively involved in regulating vascular tone.
Healthy endothelial signalling helps vessels dilate when required. Nitric oxide is one of the important signalling molecules involved in that process. When endothelial function deteriorates, vascular smooth muscle remains more constricted, oxidative and inflammatory signalling may increase, and resistance to blood flow can rise.
In that person, the therapeutic reasoning may therefore place greater emphasis on vascular tone, endothelial support and the integrity of the vessel wall. This is very different from simply asking whether a plant has demonstrated an average blood-pressure-lowering effect in a clinical trial.
3. Sympathetic nervous-system overactivity
Blood-pressure regulation is also intimately connected with the autonomic nervous system.
The sympathetic nervous system increases heart rate, cardiac output and vascular tone when the body needs to respond to demand or threat.
That response is entirely physiological. The problem arises when sympathetic activation becomes persistently elevated or poorly regulated. Stress, sleep disturbance, obstructive sleep apnoea and other physiological disturbances can all interact with autonomic regulation of blood pressure. Modern hypertension models recognise the central nervous system and sympathetic signalling as important components of the disorder. For this person, simply choosing a vasodilating herb may miss an important part of the picture.
4. Metabolic dysfunction
Hypertension frequently exists within a broader cardiometabolic picture. Obesity, insulin resistance, abnormal glucose regulation, dyslipidaemia and physical inactivity can interact with vascular, renal, inflammatory and sympathetic pathways that influence blood pressure. The WHO identifies obesity, inactivity, dietary factors and diabetes among important hypertension risk factors and associated conditions.
This means that in someone with hypertension alongside insulin resistance, raised triglycerides, central adiposity or impaired glucose regulation, treating blood pressure in isolation may make little physiological sense. The cardiovascular and metabolic systems are communicating with one another. Our treatment strategy should recognise that.
So how does clinical herbal medicine approach this differently?
This is where herbal formulation becomes important. A clinical herbal formula is not simply a collection of plants that have all appeared on a list of “herbs for high blood pressure.”
We identify the dominant physiological picture and then select plants whose actions make sense within that picture.
For example, where increased vascular resistance and endothelial dysfunction appear important, a formula might contain several plants selected for complementary actions relevant to vascular regulation.
Where fluid and renal regulation are more prominent, the formulation logic may be different.
Where metabolic dysfunction is strongly involved, the treatment may place considerably more emphasis on glucose regulation, lipid metabolism, diet, weight management and cardiometabolic function.
And where persistent sympathetic activation, poor sleep and chronic stress are significant contributors, autonomic regulation may need to form part of the therapeutic strategy.
Frequently, of course, these patterns overlap. That is why herbal formulation is a process of clinical reasoning, rather than matching one disease name to one plant.
But don't some herbs lower blood pressure?
Yes. There is human clinical evidence that certain botanical preparations can reduce blood pressure. For example, systematic reviews of Hibiscus sabdariffa have found reductions in systolic and diastolic pressure in people with mild-to-moderate hypertension, although responses vary between populations and studies.
A 2024 systematic review of aged garlic extract trials also found modest reductions in systolic and diastolic pressure among people with hypertension.
Olive leaf (Olea europaea) has increasingly interesting clinical evidence. A 2025 systematic review found potential reductions in blood pressure, while a large randomised placebo-controlled trial subsequently reported reductions in 24-hour systolic pressure alongside improvements in several cardiometabolic markers. The evidence is promising, although preparation, dose and study quality still matter.
Celery preparations have also been investigated. A 2025 systematic review of randomised trials reported improvements in blood pressure as well as some glycaemic and lipid measures, but substantial heterogeneity and relatively small studies mean the findings still require careful interpretation.
These studies are important.But they do not mean that hibiscus, garlic, olive leaf or celery is automatically “the herb for hypertension.” That would take us straight back to the problem we started with. The clinical question remains:
Does this plant — in this preparation, at an appropriate dose — make sense for this particular patient and this particular physiological picture?
From plant action to formulation
This is one of the most important distinctions between simply consuming a medicinal plant and practising clinical herbal medicine. A plant can have several pharmacological actions. A formula can bring together several plants whose actions complement one another. And the formula can be changed according to what we are trying to achieve.
We may be thinking about:
- vascular tone;
- endothelial function;
- nitric-oxide signalling;
- renal and fluid regulation;
- sympathetic nervous-system activity;
- metabolic health;
- oxidative and inflammatory vascular stress;
- sleep and recovery;
- or the wider cardiovascular risk picture.
Not every patient needs every one of these addressed. That is precisely the point: The formulation follows the physiology.
An old principle with a modern physiological basis
The article that inspired this discussion, Eric Yarnell and Kathy Abascal's Treating Hypertension Botanically, was published in 2001. Its opening principle remains remarkably relevant: there is no single botanical treatment for hypertension because hypertension differs according to aetiology, risk factors and the individual.
Twenty-five years later, our understanding of hypertension has become considerably more sophisticated. Current European guidelines describe blood-pressure regulation as an interaction between genes, environment, behaviour, renal function, cardiovascular physiology, central nervous-system signalling, neurohormonal pathways, vascular mechanisms and immune biology.
That complexity does not make treatment less rational. It makes individualisation more important.
Treat the physiology, not simply the label
There is an understandable temptation to reduce herbal medicine to:
Condition → herb.
Insomnia → valerian.
Anxiety → passionflower.
Hypertension → hibiscus.
But clinical herbal medicine can be much more sophisticated than that. Two people may share the diagnosis of hypertension while having substantially different contributing physiology. So rather than beginning with:
“What herb treats hypertension?”
we begin with:
“Why might blood pressure be elevated in this person, and which physiological processes can we reasonably influence?”
From there, the herbs, preparation and formulation can be chosen with purpose. Because the same blood-pressure reading can arise from very different biology. And different biology calls for different treatment.
A note on safety
Hypertension is an important medical condition and herbal treatment should not replace appropriate medical assessment or prescribed antihypertensive therapy. Some medicinal plants can add to the effects of blood-pressure medicines or interact with other medication, and treatment therefore needs to take the person's full medication and health history into account.
Clinical herbal medicine grounded in science and individualised care.
Wildberry Clinic
References
Yarnell E, Abascal K. Treating Hypertension Botanically. Alternative & Complementary Therapies. 2001;7(5):284–290. DOI: 10.1089/107628001753312121.
McEvoy JW, et al. 2024 ESC Guidelines for the management of elevated blood pressure and hypertension. European Heart Journal. 2024;45(38):3912–4018.
World Health Organization. Hypertension. Updated September 2025.
Abdelmonem M, et al. Efficacy of Hibiscus sabdariffa on reducing blood pressure in patients with mild-to-moderate hypertension: a systematic review and meta-analysis of published randomized controlled trials. Journal of Cardiovascular Pharmacology. 2022;79(1)–e74.
Hasanzadeh S, et al. Effects of aged garlic extract on blood pressure in hypertensive patients: a systematic review and meta-analysis of randomized controlled trials. 2024.
Lachovicz R, et al. Efficacy of olive leaf extract in improving blood pressure in pre-hypertensive and hypertensive individuals: a systematic review and meta-analysis. Phytotherapy Research. 2025.
Liu D, et al. Effects of celery (Apium graveolens) on blood pressure, glycaemic and lipid profile in adults: a systematic review and meta-analysis of randomized controlled trials. Frontiers in Nutrition. 2025;12:1597680.
Recent Posts











