The short answer
Do not combine ephedrine-alkaloid-containing Ephedra sinica with phenelzine. The medication warnings indicate a potentially dangerous blood-pressure interaction. This is an avoidance issue, not one that can be addressed by taking the products a few hours apart.
What this answer covers
Oral Ephedra sinica stem or above-ground preparations containing ephedrine-type alkaloids. The assessment does not equate root preparations, other species, purified ephedrine products or unverified alkaloid-free products.
- Supplement or preparation
- Ephedra sinica
- Medication ingredient
- phenelzine
Why this can be dangerous
Ephedrine-type alkaloids stimulate adrenergic activity. MAOI treatment can make interactions with this kind of stimulant dangerous. The warning applies when the ephedra preparation contains those constituents, even if it is sold as an herb.
Check the plant part and ingredients
Ephedra sinica is a species name, not a complete product description. Stem preparations, roots and mixtures should not be assumed to contain identical chemicals. An unclear label is a reason for professional review, not reassurance.
Avoidance and washout are different from spacing
The oral ephedrine label says not to use it while taking an MAOI or for two weeks after stopping one. Do not stop your antidepressant to start a supplement. Any medication change or washout should be directed by your prescriber.
What the evidence can establish
The recommendation rests on medication and constituent warnings with a documented botanical bridge, rather than a trial of this exact pair. Ephedrine alkaloids in dietary supplements are prohibited by the FDA; serious symptoms such as severe headache or chest pain require urgent assessment.
Evidence and practical considerations
Side effects & toxicity
Phenelzine prohibits sympathomimetic agents. Ephedrine oral labeling separately prohibits use during MAOI treatment and for two weeks after stopping. Ephedra sinica stem contains relevant alkaloids.
- Exact scope
- Oral Ephedra sinica stem or above-ground preparations containing ephedrine-type alkaloids. The assessment does not equate root preparations, other species, purified ephedrine products or unverified alkaloid-free products. with Oral phenelzine tablets; current sulfate-tablet labeling uses the named active ingredient.
- Medication form and route
- oral
What remains uncertain
- The botanical application uses a plant/constituent bridge. No exact Ephedra sinica coadministration trial was identified; composition and amount vary.
Factors that may matter: Exact supplement preparation and complete concomitant-medication list require assessment..
Read the supporting source summaries
Source 1: Current U.S. prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral phenelzine sulfate tablets.
The label prohibits sympathomimetics, L-tryptophan, L-tyrosine, phenylalanine and serotonergic agents. It warns about excessive caffeine and high-tyramine exposures.
How this applies: Primary authority for phenelzine oral-tablet precautions; each article identifies whether the supplement is named or the application is a constituent/class inference.
Regulatory instructions do not quantify an exact-pair event rate or validate every botanical formulation.
Source 2: U.S. oral-product labeling
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Users of the labeled oral ephedrine hydrochloride product.
Do not use during prescription MAOI treatment or for two weeks after stopping an MAOI. The label also warns about blood-pressure and heart-rate increases.
How this applies: Constituent-level warning applicable to ephedrine-containing ephedra preparations; no botanical coadministration trial is claimed.
The source concerns a specific ephedrine salt and product. The botanical bridge depends on actual ephedrine-alkaloid content, not shared wording alone.
Source 3: Federal botanical evidence summary
ods.od.nih.gov · Source check Sep 10, 2026
Population: Botanical and clinical literature summarized by NIH; not patients receiving the exact MAOI pair.
The source identifies ephedrine and related adrenergic alkaloids in stems and distinguishes ephedra species.
How this applies: Historical fact sheet contains outdated marketing context. Used only for plant/part/constituent information, not current regulatory status or exact-pair outcome rates.
Historical fact sheet contains outdated marketing context. Used only for plant/part/constituent information, not current regulatory status or exact-pair outcome rates.
Source 4: Federal safety information
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of ephedra-containing products.
NCCIH describes serious cardiovascular and neurologic risks and the FDA prohibition on ephedrine alkaloids in dietary supplements.
How this applies: Does not establish a measured interaction rate with phenelzine or tranylcypromine. Does not cover every ephedra species or plant part.
Does not establish a measured interaction rate with phenelzine or tranylcypromine. Does not cover every ephedra species or plant part.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Initial targeted research draft. Inspected source material, adjudicated the current checker statements, and recorded preparation limits. Clinical review has not occurred. | |
| Research summary published |
Article revision: c5ff1434451b1847
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.