The name "hawthorn" is derived from "hedgethorn," reflecting this spiny tree's use as a living fence in much of Europe. Besides protecting estates from trespassers, hawthorn has also been used medicinally since ancient times. Roman physicians used hawthorn as a heart drug in the first century AD, but most of the literature from that period focuses on its symbolic use for religious rites and political ceremonies.

During the Middle Ages, hawthorn was used for the treatment of dropsy, a condition we now call congestive heart failure. It was also used for treating other heart ailments as well as for sore throat.

What Is Hawthorn Used for Today?

Meaningful evidence indicates that hawthorn is a safe and effective treatment for congestive heart failure (CHF). Like other treatments used for CHF, hawthorn improves the heart's pumping ability. However, it may offer some important advantages over certain conventional drugs used for this condition.

Digoxin, as well as other medications that increase the power of the heart, also make the heart more susceptible to dangerous irregularities of rhythm (arrhythmias). In contrast, preliminary evidence indicates that hawthorn may have the unusual property of both strengthening the heart and stabilizing it against arrhythmias.1-3

It is thought to do so by lengthening what is called the refractory period. This term refers to the short period following a heartbeat during which the heart cannot beat again. Many irregularities of heart rhythm begin with an early beat. Digoxin shortens the refractory period, making such a premature beat more likely, while hawthorn protects against such potentially dangerous breaks in the heart's even rhythm.

Another advantage of hawthorn is its lower toxicity. With digoxin, the difference between the proper dosage and the toxic dosage is dangerously small. Hawthorn has an enormous range of safe dosing.4

However, keep in mind that digoxin is itself an outdated drug. There are a great many newer drugs for CHF (such as ACE inhibitors) that are much more effective than digoxin. Many of these have been proven to prolong life in people with advanced CHF. There is as yet no reliable evidence that hawthorn offers the same benefit (although one large study found tantalizing hints that it might).22 One small study concluded that it may be safe to combine hawthorn and digoxin,23 but whether hawthorn interacts safely with other heart drugs remains to be determined.

Finally, CHF is simply too dangerous a condition to rely solely on self-treatment.

The bottom line: If you have CHF, do not use hawthorn except under close physician supervision.

The bottom line: If you have CHF, do not use hawthorn except under close physician supervision.

In addition to CHF, hawthorn is sometimes used as a treatment for annoying heart palpitations that have been thoroughly evaluated and found to be harmless. Common symptoms include occasional thumping as well as episodes of racing heartbeat. These may occur without any identifiable cause and may not require any medical treatment, except for purposes of comfort. However, there is no evidence that hawthorn is effective for this purpose. Furthermore, because there are many dangerous kinds of heart palpitations, it is absolutely necessary to get a thorough checkup first. It is only worth considering hawthorn as a treatment for palpitations if a doctor tells you that you have no medically significant heart problems.

Hawthorn is sometimes recommended for the treatment of high blood pressure, but its effects appear to be marginal at best.5,6,13,20 Furthermore, there is some evidence that a combination herbal treatment made from hawthorn and camphor can help prevent the sudden fall in blood pressure that may occur on standing up from a sitting or lying position (orthosatic hypotension).16,17 In these studies, the mixture acted to increase blood pressure.

Hawthorn has also been tried for other heart-related conditions, such as angina and atherosclerosis in general, but there is no reliable evidence to support these uses.

What Is the Scientific Evidence for Hawthorn?

At least nine reasonable quality, double-blind, placebo-controlled trials, involving a total of more than 750 participants, have found hawthorn effective for the treatment of mild to moderate congestive heart failure.12,14,15,18,19

In one of the best of these studies, 209 people with relatively advanced congestive heart failure (technically, New York Heart Association [NYHA] class III) were given either 1,800 mg or 900 mg of standardized hawthorn extract or matching placebo.15 The results after 16 weeks of therapy showed significant improvements in the hawthorn groups as compared to the placebo groups. Benefits in the high-dose hawthorn group included a reduction in subjective symptoms as well as an increase in exercise capacity. Subjective symptoms improved to a similar degree in the lower-dose hawthorn group, but there was no improvement in exercise capacity.

In an analysis that mathematically combined the results of 10 controlled trials involving 855 patients, hawthorn extract was found to be significantly better than placebo for improving exercise tolerance, decreasing shortness of breath and fatigue, and enhancing the physiologic function of an ailing heart in mild to moderate CHF.24

In another study, however, researchers found that patients with mild-to-moderate CHF taking a special extract of hawthorn,900 mg daily, were more likely to experience an initial worsening of their condition compared to those taking a placebo. But, by the end of six months, there was no difference in the two groups. In light of numerous other studies supporting the safety and effectiveness of hawthorn in CHF, the results of this special extract study need to be repeated before drawing any firm conclusions.25

A comparative study suggests that hawthorn extract (900 mg) is about as effective as a low dose of the conventional drug captopril.10 However, while captopril and other standard drugs in the same family have been shown to help reduce hospitalizations and mortality associated with CHF, there is no similar evidence for hawthorn.

Dosage

The usual dosage of hawthorn is 300 to 600 mg 3 times daily of an extract standardized to contain about 2% to 3% flavonoids or 18% to 20% procyanidins. Studies indicate that full effects may take up to 6 months to develop, although some improvement should be apparent much sooner.

Safety Issues

Hawthorn appears to be generally safe. Germany's Commission E lists no known risks, contraindications, or drug interactions with hawthorn, and mice and rats have been given very large doses without showing significant toxicity.11 In clinical trials, reported side effects were relatively rare and nonspecific, consisting primarily of mild dizziness, stomach upset, headache, and occasional allergic reactions (skin rash).21

Perhaps the biggest risk with hawthorn is that using it instead of conventional treatment might increase risk of death or other complications of CHF. In addition, it is not known whether hawthorn can be safely combined with other drugs that affect the heart. Therefore (to reiterate), do not self-treat CHF with hawthorn.  A physician's supervision is essential.

Safety in young children, pregnant or nursing women, or those with severe liver, heart, or kidney disease has not been established.

Interactions You Should Know About

  • If you are taking any medications that affect the heart: It is possible that taking hawthorn could cause problems.