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Limited evidenceHeart & metabolic

Black Tea Theaflavins

Theaflavins are the pigments that make black tea black, sold as a liver-friendlier alternative to high-dose EGCG for cholesterol. The landmark trial used a mixed extract that also contained green tea catechins, so the theaflavin-specific evidence is far thinner than the marketing implies.

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What the science says

  • Lowers LDL cholesterol Limited evidence

    In the best-known RCT (n = 240, 12 weeks, mildly hypercholesterolemic adults on a low-fat diet), a theaflavin-enriched green tea extract lowered total cholesterol by 11.3% and LDL-C by 16.4% relative to placebo. Critically, the capsule contained 75 mg of theaflavins alongside roughly 150 mg of green tea catechins and other polyphenols — the effect cannot be attributed to theaflavins, and theaflavin-only trials have not convincingly reproduced it.

  • Reduces body fat Limited evidence

    A 10-week randomized, double-blind pilot in 30 Japanese adults reported that 50–100 mg/day of theaflavin improved body fat percentage, subcutaneous fat and skeletal muscle percentage versus placebo, while 400 mg of catechin did not. Thirty participants split across four arms is a hypothesis-generating pilot, not a basis for buying a fat-loss product.

  • Antimicrobial and oral-health effects Limited evidence

    Theaflavins inhibit oral bacteria and several viruses in vitro, and a small randomized placebo-controlled study in Japanese subjects found effects on oral bacterial counts. There are no clinical endpoint data — no caries, gingivitis or infection outcomes.

Dosage & safety

Studied doseStudies used 75 mg/day of theaflavins within a mixed tea extract, or 50–100 mg/day of isolated theaflavins, over 10–12 weeks. Commercial black tea extracts are typically standardised to 20–40% theaflavins at 300–500 mg per capsule, which lands in or above the studied range — but many also carry undeclared catechins and caffeine.
SafetyTheaflavins are large, poorly absorbed molecules and are generally well tolerated; GI upset is the most common complaint. Unlike high-dose EGCG, isolated theaflavins have not been associated with hepatotoxicity — but many products labelled "black tea extract" also contain green tea catechins, so read the full label if liver safety is the reason you chose them. Tea polyphenols substantially reduce non-heme iron absorption when taken with meals; take away from iron-rich meals or iron supplements. Caffeine content varies by product. Not studied in pregnancy at supplemental doses.

How to take it

TimingTiming does not matter.
With food?With food, but away from iron-rich meals and iron supplements.
Worth knowingCheck whether your "black tea extract" also contains green tea catechins and caffeine — many do, and that changes both the liver-safety and stimulant picture.

Interactions

With other supplements

  • iron supplements

    Tea polyphenols substantially reduce non-heme iron absorption. separate by at least 2 hours

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Do black tea theaflavins lower cholesterol?

The evidence that black tea theaflavins lower cholesterol is limited: the best-known trial cut LDL-C by 16.4% over 12 weeks, but its capsule also contained about 150 mg of green tea catechins alongside 75 mg of theaflavins. Theaflavin-only trials have not convincingly reproduced the effect.

Do theaflavins help with fat loss?

A 10-week pilot in 30 Japanese adults reported better body fat percentage with 50-100 mg/day of theaflavins versus placebo (limited evidence). Thirty people split across four arms is hypothesis-generating, not a basis for buying a fat-loss product.

Is black tea extract safer for the liver than green tea extract?

Isolated theaflavins have not been associated with liver injury, unlike high-dose EGCG, but many products labelled black tea extract also contain green tea catechins and caffeine. If liver safety is why you chose theaflavins, read the full label.

Can I take black tea theaflavins with iron?

Tea polyphenols, including those in black tea theaflavin extracts, substantially reduce non-heme iron absorption. Take the extract away from iron-rich meals and separate it from iron supplements by at least 2 hours.

Scientific references

Where to buy

Life Extension, Theaflavin, Standardized Black Tea Extract, 30 Vegetarian Capsules (400 mg per Capsule)

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