The short answer
Check the caffeine content before combining green tea extract with phenelzine. Caffeine-containing products may add to the medication's blood-pressure risk, particularly with high total intake. It would be too broad to say that every Camellia sinensis preparation has the same interaction.
What this answer covers
Camellia Sinensis Leaf Extract, taken orally; the extraction method and caffeine content matter. This does not cover topical tea preparations.
- Supplement or preparation
- Camellia Sinensis Leaf Extract
- Medication ingredient
- phenelzine
Tea and extract are different exposures
A leaf beverage, concentrated capsule and decaffeinated extract are not interchangeable. For an extract, check both the preparation and any declared caffeine amount. A general green-tea name does not establish that a capsule is caffeine-free.
Why the warning is conditional
The strongest reason for caution here is the caffeine warning attached to phenelzine. It is an inference from the constituent and the medication label, rather than a measured risk in people taking this exact tea product with the drug.
What contrary research means
One randomized study of a defined decaffeinated green-tea capsule in healthy adults found lower blood pressure. This challenges a blanket claim that all tea extracts raise it, but those participants were not receiving this MAOI.
Discuss the actual product
Show your prescriber the label and include coffee, energy drinks and other caffeine sources in the discussion. A few hours of spacing has not been established as protection. Get urgent care for a sudden severe headache, chest pain or severe blood-pressure symptoms.
Evidence and practical considerations
Side effects & toxicity
Phenelzine labeling warns against excessive caffeine, while tea products can supply caffeine. A trial of one decaffeinated extract lowered blood pressure in healthy volunteers, showing why preparation matters.
- Exact scope
- Camellia Sinensis Leaf Extract, taken orally; the extraction method and caffeine content matter. This does not cover topical tea preparations. with Oral phenelzine tablets; current sulfate-tablet labeling uses the named active ingredient.
- Medication form and route
- oral
What remains uncertain
- No exact MAOI plus Camellia preparation trial was identified. The decaffeinated trial is not evidence that tea is safe with this medication.
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: Federal botanical safety information
nccih.nih.gov · Source check Sep 10, 2026
Population: Consumers of green tea beverages, oral extracts and a distinct topical prescription preparation.
Tea contains caffeine; oral extracts differ from beverages and can have adverse effects including increased blood pressure.
How this applies: Not an exact MAOI interaction study. The botanical name alone cannot establish caffeine content, extract equivalence or suitability of a specific product.
Not an exact MAOI interaction study. The botanical name alone cannot establish caffeine content, extract equivalence or suitability of a specific product.
Source 3: Randomized placebo-controlled human trial
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 111 healthy adult volunteers aged 21 to 70; not a MAOI-treated population.
The tested preparation reduced blood pressure; adverse events were few, mild and similar to placebo.
How this applies: Contrary evidence to an indiscriminate claim that all tea preparations raise blood pressure; not evidence refuting the caffeine-MAOI warning.
Abstract only. One decaffeinated preparation does not establish safety with an MAOI or transfer to other tea extracts.
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: b8c0f9c5e93acba8
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.