Herbal traditions have used these plants for centuries, but we like to go a step further and look at what modern research actually shows. Below are seven herbs in our Heart & Blood Vessels loose leaf blend, along with a plain-language look at the peer-reviewed studies behind each one.
Hawthorn – Flower and Leaves (Crataegus laevigata)
In a randomized, double-blind, placebo-controlled clinical trial, a flower-and-leaf preparation of C. laevigata added to standard statin treatment lowered LDL cholesterol and non-HDL cholesterol in diabetic patients with chronic coronary heart disease over six months. In a separate randomized controlled trial, daily hawthorn extract produced a significantly greater reduction in diastolic blood pressure than placebo in patients with type 2 diabetes already taking prescribed medication. A comprehensive review of hawthorn's role in atherosclerosis found that its extracts consistently lower blood lipids, fight oxidative stress, and protect the vascular endothelium — the inner lining of blood vessels where plaque begins to form. 🔗 LDL cholesterol trial (PubMed) · Blood pressure trial (PubMed) · Atherosclerosis review (PubMed)
Ginkgo (Ginkgo biloba)
In a randomized study in healthy elderly adults, Ginkgo biloba extract significantly increased coronary blood flow, an effect linked to improved function of the endothelium — the inner lining of blood vessels responsible for healthy dilation. In an earlier randomized, placebo-controlled crossover study, a single dose of Ginkgo biloba significantly increased blood flow in the nail fold capillaries by about 57% within an hour, without any change in blood pressure or heart rate. Separately, in patients with peripheral arterial occlusive disease, 48 weeks of Ginkgo biloba extract improved blood cell flexibility and measurably increased the pain-free walking distance these patients could achieve. 🔗 Coronary blood flow study (PubMed) · Peripheral microcirculation study (PubMed) · Peripheral arterial disease study (PubMed)
Breckland Thyme (Thymus serpyllum)
In a study using an established animal model of high blood pressure, an aqueous extract of Breckland (wild) thyme produced a significant reduction in systolic blood pressure, diastolic blood pressure, and total peripheral resistance, with no effect seen in normal-pressure animals — indicating the extract works specifically to correct elevated pressure rather than acting as a general sedative on the cardiovascular system. The extract's high content of rosmarinic and caffeic acids was linked to both strong antioxidant activity and meaningful nitric oxide-scavenging capacity, two properties relevant to protecting blood vessel walls. A comprehensive review of wild thyme's health benefits confirmed this antihypertensive and antioxidant activity as one of its most well-documented pharmacological properties. 🔗 Antihypertensive study (PubMed) · Health benefits review (PubMed)
Motherwort (Leonurus cardiaca)
Motherwort has a long traditional use as a cardiotonic herb for calming a racing heart and easing tension linked to cardiovascular strain. In an open clinical trial, patients with stage 1 and 2 arterial hypertension who took a Leonurus cardiaca oil extract for 28 days showed significant improvements in systolic blood pressure, diastolic blood pressure, and heart rate, alongside improvements in the anxiety and sleep disturbances that often accompany high blood pressure. 🔗 Human hypertension clinical trial (PubMed)
Thyme (Thymus vulgaris)
In an animal model of hypertension induced by restricting blood flow to the kidney, eight weeks of Thymus vulgaris extract produced a clear antihypertensive effect while also reducing hypertension-related increases in cholesterol, and protected the thoracic aorta from the structural damage to its endothelial lining seen in untreated hypertensive animals. Complementing this, laboratory testing on isolated rat aorta found that thymol and carvacrol, thyme's two dominant compounds, both produced genuine vasorelaxant effects on blood vessel tissue. 🔗 Blood pressure/aorta protection study· Vasorelaxant compound study
Rosemary (Rosmarinus officinalis)
In a recent clinical trial, healthy volunteers and patients with grade 1 hypertension who drank a daily rosemary leaf infusion for 45 days experienced a genuine reduction in blood pressure, an effect the researchers linked to rosemary's rosmarinic acid content acting on blood vessel dilation and inflammation. Interestingly, a separate clinical trial found that rosemary essential oil produced the opposite, blood pressure-raising effect in patients with chronically low blood pressure, suggesting rosemary may help support healthy circulation from either direction depending on the preparation and starting point. In an animal model of heart attack, rosemary supplementation reduced harmful remodeling of heart tissue afterward, improving heart function and lowering oxidative stress in the damaged heart muscle. 🔗 Human hypertension trial · Human hypotension trial · Cardiac remodeling study (PMC)
Nettle (Urtica dioica)
In a pharmacological study, continuous perfusion of an aqueous nettle extract produced a dose-dependent reduction in blood pressure alongside a correlated increase in diuresis and sodium excretion — helping the body clear the excess fluid that can contribute to elevated blood pressure. This dual action supports nettle's traditional use for both cardiovascular and circulatory support. 🔗 Diuretic/blood pressure study (PubMed)
Why This Matters
Each of these herbs has been studied individually for its effects on the heart and blood vessels — with genuine human clinical trial evidence for hawthorn, ginkgo, motherwort, and rosemary specifically on blood pressure and circulation. We combine them because their documented modes of action support cardiovascular health from several different angles: relaxing and protecting the blood vessel wall, improving blood flow to the heart and extremities, helping regulate blood pressure in either direction, and reducing the oxidative stress that drives long-term vascular damage.
This post is for educational purposes and summarizes existing scientific literature. It is not medical advice, and our blend is not intended to diagnose, treat, cure, or prevent any disease. Please consult a healthcare provider before using herbal supplements, especially if you have diagnosed heart disease, high or low blood pressure, or are taking blood pressure, heart, or blood-thinning medication, as several of these herbs have measurable effects on blood pressure and circulation that could interact with your treatment.