Dangers of Ma-huang

October 1998; Volume 1: 119

Source: Powell T, et al. Ma-huang strikes again: Ephedrine nephrolithiasis. Am J Kidney Dis 1998;32:153-159.

Ephedrine and its metabolites are naturally occurring alkaloids that can be derived from evergreens worldwide, and they have been used as medicinals for centuries. The alternative medicine industry has popularized them as "herbal ecstasy" and "herbal phen-fen" and suggested many uses, including asthma control, weight loss, and energy and sexual enhancement. Several recent reviews have documented the dangerous nature of using these "drugs" unsupervised, including multiple deaths, and the FDA is currently reviewing ephedrine's use in the alternative medicine industry.

We report a new toxicity, ephedrine nephrolithiasis, in a patient using an energy supplement, Ma-huang extract, which contains ephedrine. Although previously unreported, the Louis C. Herring and Company kidney stone database shows that this is an endemic complication of ephedrine with hundreds of previous episodes. Using gas chromatography (GC) mass spectrometry, we were able to identify the chemical structure of our patient's stone, as well as other similar stones from Louis Herring, as containing ephedrine, norephedrine, and pseudoephedrine.


A 27-year-old male smoker with a history of body building, hypertension, and a congenitally absent left kidney developed a ureterovesical junction stone requiring basket retrieval. Three months later, he presented with a recurrence and acute renal failure. Two radiolucent stones 2 mm and 12 mm in length were removed, and the patient's creatinine dropped from 4.3 mg/dL to 1.3 mg/dL. Crystallographic laboratory analysis revealed 95% ephedrine metabolite and 5% protein matrix. The patient had been taking up to 12 tablets daily of Pro-Lift to enhance body building. Each tablet contains 170 mg of Ma-huang (6% ephedrine).

To their credit, the investigators called the lab, which sent them seven more stones like those of their patient. These stones also contained ephedrine. Of the 166,466 stones in the registry from January 1996-June 1997, 106 (0.06%) contained ephedrine. Seven of 15 questionnaires returned to the lab by the former stone carriers admitted to using more than 25 tablets daily of various ephedrine or pseudoephedrine preparations.

Ephedrine has played a starring and startling role in herbal medicine. At least 44 deaths have been associated with ephedrine, and the State of Florida, for one, has restricted its sale. The FDA has cautioned against ingesting more than 24 mg daily. A nonspecific alpha and beta agonist, ephedrine's effects in herbal phen-fen are intended to mimic those of the anorexigenic agent phentermine, but appetite suppressant effects too often vaporize with proximity to the vending machine. Unfortunately, ephedrine's toxicity does not.


No one should take Ma-huang for anything until it is re-classified as a pharmaceutical, its formulation is standardized, and its use can be carefully monitored. It is especially dangerous in patients with cardiovascular disease, hypertension, and, apparently, renal stone formers. People who do take it must hydrate themselves adequately-a minimum of eight glasses of water daily, and more for regular exercisers-as ephedrine is highly water soluble.