Green Tea Extract and medications.
Green Tea Extract is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.
Green tea extract is concentrated for EGCG, the catechin behind most of its effects. The Grade B evidence supports a small lift in fat oxidation, some LDL cholesterol reduction, and general antioxidant and cardiovascular benefit. The important detail most products get wrong is dosing on EGCG content, around 400 to 500mg, not total extract weight, which is why many supplements are effectively underdosed. There is a real liver-safety point, and it is not a simple dose ceiling. Rare, idiosyncratic liver injury has been reported across EGCG intakes from about 140mg up to 1000mg a day, a range that spans and sits below the effective dose, with large differences between people in susceptibility, so 800mg is not a safe line to stay under. Take it with food and never on an empty stomach, since fasted dosing raises absorption and liver risk; do not use it if you have a liver problem; and stop and see a doctor promptly on any sign of liver trouble such as jaundice, dark urine, abdominal pain or unusual fatigue. It should not be stacked with other compounds that stress the liver. Separate it from iron by two hours, and treat anticoagulants as a reason for mild caution because of slight blood thinning. It is also not recommended for anyone with a current or past eating disorder, since its stimulant and appetite-suppressant effect can reinforce restrictive patterns. If you are caffeine-sensitive, choose a decaffeinated form. Read the EGCG number, respect the upper limit, and it is a reasonable metabolic support.
Below are the 7 documented pairs we have explicitly assessed for Green Tea Extract: 7 amber. The pairs cluster around 3 mechanisms: CYP1A2 inhibition, OATP transporter inhibition (reduced absorption), and Vitamin K pathway. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 14 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
CYP1A2 inhibition
Amber Does interact with Fluvoxamine?
Fluvoxamine slows the enzyme that breaks down caffeine, and green tea extract contains caffeine. Taking the two together can let caffeine build up and may cause jitteriness, a racing heart, or trouble sleeping. Choosing a decaffeinated or low-caffeine green tea extract, or keeping the dose modest, lowers the risk.
Evidence: Supported by human study data.
OATP transporter inhibition (reduced absorption)
Amber Does interact with Atenolol?
Green tea catechins can lower how much atenolol your body absorbs, which may make the beta-blocker less effective at controlling blood pressure or heart rate. The clearest evidence is for a related beta-blocker called nadolol, where green tea cut absorption sharply; atenolol travels through the same gut transporter, so the same effect is plausible. A practical step is to separate green tea extract from your atenolol dose by a few hours and to keep your intake steady rather than starting or stopping it suddenly.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Atorvastatin?
Green tea extract may lower the amount of atorvastatin your body takes up, because both rely on the same cell transporter. This is suggested by reviews of related statins rather than by a direct atorvastatin study, so the size and importance of any effect are not yet clear. Keeping your green tea extract intake steady and telling your prescriber you take it is a reasonable precaution, particularly around a cholesterol check.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Nadolol?
Green tea can sharply cut how much nadolol your body absorbs, which can leave the beta-blocker working much less well at controlling your blood pressure or heart rate. In a study in healthy people, drinking green tea reduced nadolol levels in the blood by about 85 percent and blunted its blood-pressure effect. If you take nadolol, it is best not to take it with green tea or green tea extract: keep them several hours apart, keep your intake steady rather than starting or stopping suddenly, and tell your prescriber so your readings can be checked.
Evidence: Supported by human study data.
Amber Does interact with Rosuvastatin calcium?
Green tea extract can lower the amount of rosuvastatin in your bloodstream by interfering with the transporter that moves the drug into cells. In a study of healthy volunteers, a concentrated green tea extract reduced rosuvastatin levels by about a fifth. It is not certain whether this changes how well rosuvastatin lowers cholesterol, so the sensible approach is to keep your green tea extract intake steady and let your prescriber know you take it, especially around a cholesterol check.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Vitamin K pathway
Amber Does interact with Acenocoumarol?
Green tea contains vitamin K, which can work against acenocoumarol, a vitamin-K-based blood thinner, and changing how much you drink can swing your INR. Large or fluctuating intakes are the concern. If you take acenocoumarol, keep green tea intake steady and tell your anticoagulant clinic.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Warfarin sodium?
Green tea can work against warfarin, but the documented cases involve drinking large volumes of brewed green tea, which carries vitamin K. Concentrated green tea extract capsules contain far less vitamin K, so the same effect is less likely from a standard supplement. Either way, keep your green tea habit steady rather than changing it suddenly while on warfarin, and tell your anticoagulation clinic what you take.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
No affiliates. No commission. We earn nothing on what you buy.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyA full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
£49 introductory price for early customers. Standard price £79.
Something missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.