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Ma Huang

Ma Huang

Botanical Description & Habitat

Ephedra sinica or Ephedra equisetina


Common names

Ma Huang (Yellow Horse)
Sea grape

Found in eastern Asia

A small, erect or prostrate plant. Stems are pale green, grooved, erect, and grow from 12 to 35 inches in height. The leaves are scale-like and reach two to four millimeters in length. Yellowish-green flowers grow in terminal catkins; female catkin later develops into a poisonous berry. The flowers are horse-shaped.

Medicinal parts
Root or stem - dried

Historical Properties & Uses

Ma huang, a member of the species Ephedra, is a source of the powerful pressor drug ephedrine. The plant shares many of the same properties, to a lesser degree, but is much less toxic than the pure substance.

Ma huang has proven vasodilatory, hypertensive (pressor), circulatory stimulant, and anti-allergic properties. Both ephedrine and ma huang find primary application in mild to severe allergic reactions, from hay fever to asthma. In Asia, Ephedra species are used to treat asthma, rheumatism, syphilis, cardiac insufficiency, malaria, influenza, post-partum problems, typhoid, and other feverous conditions.

This herb has approval status by the German Commission E for diseases of the respiratory tract.


Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Method of Action

Ma huang is a nasal decongestant and anti-asthmatic
Ephedra and ephedrine, the active alkaloid, are used for their ability to clear nasal congestion and asthma. Other sympathomimetic effects are produced: such as, elevation of blood pressure, stimulation of the central nervous system (which makes it a good treatment for narcolepsy), dilation of the pupils, nervousness, and insomnia. Other symptoms are listed in the Toxicity section.

Ma huang has a powerful and fast-acting anti-allergic property. The two major components of ephedra, ephedrine (E) and pseudo-ephedrine (PE), possess the following proven physiological properties:

1. Both E and PE stimulate the sympathetic and vagus nerve-endings of the heart. E also stimulates the sympathetic ganglia.

2. Both E and PE have a pressor action, E being more powerful than PE; the rise of blood pressure is produced by direct stimulation of the vasomotor nerve endings. With PE, the persistent rise seen after paralysis of the vasomotor nerves is due to the increase of cardiac output and the stimulation of the muscles of the blood vessels.

3. PE stimulates the myocardium while E, especially in large doses, depresses it.

4. PE dilates the bronchioles and contracts the mucous membrane of the nose almost as much as does E. PE has no action on the respiratory center, hence its value as an anti-asthmatic.

5. PE is a more powerful diuretic than E. Its action is mainly vascular; the vessels of the kidneys are dilated and the volume of the organ is increased. PE's diuretic action is valuable as a cardiac tonic where edema is present.

6. Both E and PE are useful in asthma and as cardiac stimulants; however, E yields more unpleasant side effects, especially in the treatment of asthma.

Ma huang has hyperglycemic properties
One interesting study compared the effects of the individual alkaloids to a crude extract of the plant when administered duodenally to intact dogs. With respect to pressor and hyperglycemic effects, changes in time course of the effects produced by these two drug preparations were similar and, in either of the two physiological parameters, the maximal value given by the extract was about half that given by the alkaloid fraction.

A maximum level of blood pressure and blood glucose concentration was reached 10-15 minutes after administration of the two drug preparations, while the amount of alkaloid absorbed in the portal vein by this time was about 2-3 times as much under administration of the alkaloid fraction as under administration of the extract.

Although administration of alkaloid in the extract occurred more slowly, it lasted longer. Alkaloid-free extracts had no effect on blood pressure or blood glucose concentrations, but did produce tachycardia.

It seems, therefore, the whole ephedra extract has the same effect as its individual components, but less pronounced and longer lasting.

Some additional effect on the heart might also be expected from the whole-plant extract.

Ephedrine lowers respiration
Unlike the other alkaloids in ma huang, ephedrine lowers blood pressure. It also produces a slight amplitude of respiration and contracts isolated guinea pig uterus and intestine. Ephedrine probably acts by stimulating smooth muscles and by depressing heart muscle, which accounts for the fall in blood pressure.

Drug Interactions & Precautions

Known Interactions

The combined action of ma huang and isoproterenol may lead to cardiac arrhythmia.

The German Commission E notes the following possibilities:

Disturbances of heart rhythm in combination with cardiac glycosides or Halothane.

Enhancement of the sympathomimetic effect of Guanethidine.

Raise the sympathomimetic effect of ephedrine with MAO-inhibitors (Monoamine oxidase inhibitors).

The development of hypertension with secale alkaloid derivatives.

Possible Interactions

The sympathomimetic action of the uterine relaxant ritodrine HCl and the sympathomimetic property of ma huang are additive. Furthermore, the pressor effect of this sympathomimetic agent may be markedly potentiated by monoamine oxidase inhibitors (MAOI's) and tricyclic antidepressants.

Additive pressor effects may occur when using ma huang with the analeptic doxapram HCl.

Use of ma huang in obstetrics (e.g., to correct hypotension) in conjunction with oxytocic drugs may produce hypertension. Concurrent administration of large amounts of ma huang and procarbazine antineoplastic drugs may induce a sudden hypertensive crisis. The antihistaminic property of this herb will antagonize the effects of heparin. Ma huang may decrease absorption and diuretic response to furosemide. The herb may also inhibit the stimulant effect of glucagon on insulin released by islet of Langerhans cells. Conversely, colchicine may increase sensitivity or enhance the response to ma huang.

Metabolism of ma huang may be decreased by propoxyphene, troleandomycin, para-aminosalicylic acid (PAS), antihistamines, chloramphenicol, disulfiram, halothane, isoniazid, methylphenidate, phenothiazines, and sulfa drugs.

Ma huang's analgesic effects may be additive with other analgesics and anesthetics. Conversely, those effects may be inhibited by barbiturates, despite any CNS-depressant effects which may occur. The analgesic property of the herb may be reversed or even eliminated by P-chlorophenylalaine, cyproheptadine HCl, and phenobarbital.

The CNS-depressant tendency of this analgesic may be potentiated by chlorprothixene HCl, haloperidol, and tranquilizers.


The cardiac alkaloids in ma huang may antagonize the action of heparin.

Angina pectoris drugs, such as nadolol and propranolol HCl, may reduce AV conduction induced by this herb. Additionally, ma huang has a hyperglycemic effect which could decrease responsiveness to antidiabetic drugs.

In the absence of other hard data, it may be assumed observable interactions occur between the many central nervous system drugs and the psychoactive principles in ma huang.

There is evidence to show combined use of bactericidal and bacteriostatic agents will lower the effectiveness of the bacteriostatic agent. However, how this finding applies to herbal anti-infectives is not known.


Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Safety Factors & Toxicity

Ephedra abuse can produce long-lasting hypertension, nervousness, insomnia, tremor, vertigo, headaches, tachycardia, palpitation, sweating, nausea, vomiting, loss of appetite, cardiac arrhythmia, and chronic anxiety.

Severe overdosege will cause nausea, vomiting, chills, cyanosis, fever, tachycardia, dilated pupils and blurred vision, opisthotonos, convulsions, coma, and respiratory failure.

This herb ("Ephedra") has approval status by the German Commission E.

The German Commission E recommends the use of this herb for a short-term, only.


Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Preparation & Administration

Three times a day
Do not use if hypertensive, or with monoamine oxidase inhibitors (MAOs)

Dried stems
1-4 grams

made from 1 tsp of dried stems

Fluid extract
1:1 in 25% alcohol, 1-3 ml

1:4 in 45% alcohol, 6-8 ml

This herb has approval status by the German Commission E.

Recommended daily dosages in Germany are as follows:

15 - 30 mg calculated as ephedrine.

The German Commission E recommends the use of this herb for a short-term, only.


Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Note: This Herbal Preparation information is a summary of data from books and articles by various authors. It is not intended to replace the advice or attention of health care professionals.



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