Black Tea Extract

Black tea · Theaflavins · Black tea extract

Snapshot

Indications	Contraindications
Blood pressure support¹ LDL cholesterol² Glucose tolerance³ Attention and alertness⁴ Endothelial function^5–8 Post-exercise muscle soreness⁹	Pregnancy or breastfeeding¹⁰ Caffeine sensitivity¹⁰ Surgery within two weeks¹⁰

Black tea extract concentrates theaflavins and thearubigins, the pigments formed when Camellia sinensis leaves are fermented¹¹. These pigments act largely as antioxidants that support vascular function¹². Supplementation follows from that effect: it is used for blood pressure and low-density lipoprotein (LDL) cholesterol, for glucose tolerance, and for alertness.

A Cochrane review noted that no trial reported cardiovascular events and that few trials contributed to each analysis¹³. In a 2024 mouse model of histamine-induced dermatitis, black tea and two other tea extracts reduced itching; no human trial has tested this. Products listing black tea extract are mostly tea bags, with fewer capsules and liquids; see Form comparison.

Product labels carry pregnancy and breastfeeding warnings, and some ask for a physician's advice first with heart disease, high blood pressure, or liver disorders¹⁰. Some labels also direct users to stop before surgery¹⁰.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

62 sources, 55 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources