Ma Huang and Atenolol: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 15, 2026 · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Atenolol
Ma Huang
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Atenolol (Tenormin) is a beta-blocker that helps lower your blood pressure and slow your heart rate. Ma Huang, also called ephedra, works in the opposite direction. It naturally contains ephedrine, a stimulant that can push your blood pressure and heart rate up.
When you take them together, the Ma Huang can work against your atenolol and make it less effective at controlling your blood pressure. Some people have even had a sharp spike in blood pressure. This is based mostly on theory and a few reports, so it isn't guaranteed to happen, but it's worth taking seriously. Please talk with your pharmacist or doctor before using any product with Ma Huang or ephedra.
Effect: Reduced hypotensive/antihypertensive efficacy of atenolol.
Mechanism: Pharmacodynamic antagonism. Ma Huang (ephedra) is a natural source of ephedrine and pseudoephedrine, sympathomimetics that oppose beta-blockade and raise blood pressure and heart rate. Neither agent requires metabolic activation.
- Onset: Rapid
- Evidence: Theoretical, supported by variable BP effects and a reported acute hypertensive response
- Management: Concomitant use is not advised in patients on antihypertensives. Monitor BP and heart rate if exposure occurs. Contraindicated in ephedrine/pseudoephedrine sensitivity, pheochromocytoma, or renal failure.
What happens
Reduced hypotensive effect of beta-adrenergic blockers
Interaction Deep Dive
In normotensive individuals, Ma Huang produced inconsistent effects on blood pressure1, and it may have been responsible for an acute hypertensive reaction in a patient who took an herbal product thought to contain Ma Huang2. By reducing the efficacy of antihypertensive drugs, Ma Huang (ephedra) can interfere with blood pressure control. This herb (ephedra) serves as a natural source of both ephedrine and pseudoephedrine1. Its content of ephedra alkaloids ranges from 0.5 to 2.5%. Ephedrine represents the predominant alkaloid, accounting for 30 to 90% of the overall ephedra alkaloid content, with the proportion varying according to growing conditions3. While pseudoephedrine is regarded as generally safe, ephedrine ought to be avoided in patients with hypertension4. Anyone who is sensitive to ephedrine or pseudoephedrine, as well as those with pheochromocytoma, should steer clear of products that contain these substances, including Ma Huang.
Why it happens (mechanism)
Antagonistic effect through sympathomimetic activity of ephedrine and pseudoephedrine in Ma Huang
How to manage this interaction
The main step here is avoidance. Ma Huang (ephedra) is generally not advised while you are taking a blood pressure medicine like atenolol, because its ephedrine content can counteract your treatment and raise your blood pressure.
- Keep taking your atenolol exactly as prescribed.
- Before starting any herbal supplement or weight-loss/energy product, check the label for ephedra or Ma Huang and ask your pharmacist.
- If you have used it, your care team may check your blood pressure and heart rate more closely.
- Ma Huang should be avoided entirely if you are sensitive to ephedrine or pseudoephedrine, or have pheochromocytoma or kidney failure.
Raise any planned supplement use with your pharmacist or prescriber first.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Inconsistent blood pressure responses were observed in 12 normotensive patients who took 4 capsules of ma huang (each dose providing ephedrine 19.4 mg and pseudoephedrine 4.9 mg) with breakfast, followed by an additional 4 capsules nine hours later at the evening meal. Four subjects had a significant rise in systolic blood pressure three hours after ingestion, while two subjects had a fall in diastolic blood pressure. Six (50%) patients had a significant increase in the mean 12-hour heart rate, going from 81 to 94 beats per minute (bpm), 79 to 84 bpm, 87 to 97 bpm, 77 to 83 bpm, 69 to 74 bpm, and 77 to 84 bpm (p less than 0.05 for all) 1.
b) A 21-year-old man came to the emergency department with hypertension after consuming one glass of alcohol, one marijuana cigarette, and four capsules of "herbal ecstacy" reportedly containing ginseng, kola nut, and nutmeg (elapsed time: 90 minutes). His initial blood pressure recorded by paramedics was 220/110 mmHg and was 190/116 mmHg on arrival at the emergency department, along with ventricular dysrhythmias. His symptoms cleared within 9 hours after treatment with lidocaine and sodium nitroprusside. The urine screen was positive for ephedrine or pseudoephedrine, cannabinoid metabolites, and traces of opiate and caffeine. The authors credit the patient's condition to the ephedrine content of the herbal preparation. Because the entire product had been consumed, the herbal product was not assayed to establish its relative ephedrine and caffeine contents 2.
Common questions
Can I take Ma Huang and Atenolol together?
Ma Huang (ephedra) can work against atenolol and raise your blood pressure, so it is not advised while you are on a blood pressure medicine. Check any supplement with your pharmacist before using it. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ma Huang and Atenolol interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How is the Ma Huang and Atenolol interaction managed?
The main step here is avoidance. Ma Huang (ephedra) is generally not advised while you are taking a blood pressure medicine like atenolol, because its ephedrine content can counteract your treatment and raise your blood pressure. Keep taking your atenolol exactly as prescribed. Before starting any herbal supplement or weight-loss/energy product, check the label for ephedra or Ma Huang and ask your… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Ma Huang or Atenolol need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- White LM, Gardner SF, & Gurley BJ: Pharmacokinetics and cardiovascular effects of Ma-Huang (ephedra sinica) in normotensive adults. J Clin Pharmacol 1997; 37:116-122.
- Zahn KA, Li RL, & Purssel RA: Cardiovascular toxicity after ingestion of "herbal ecstasy.". J Emerg Med 1999; 17:289-291.
- Blumenthal M & King P: Ma huang: ancient herb, modern medicine, regulatory dilemma. Herbalgram 1995; 34:22-26, 43, 56-57.
- Chua SS & Benrimoj SI: Non-prescription sympathomimetic agents and hypertension. Med Toxicol Adverse Drug Exp 1988; 3:387-417. PubMed
Keep reading about Atenolol
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