Effectiveness

Effective for treatment of genital warts4,5

Conflicting evidence for prevention and treatment of cancer 7–14

Conflicting evidence for weight loss15–18

Possibly effective for prevention of stroke10

Conflicting evidence for decreasing risk of cardiovascular disease10,19,20

Adverse effects

Central nervous system stimulation; gastrointestinal upset; case reports of hepatotoxicity involving green tea extract in pill or beverage form21

Topical ointment may cause local irritation6

Interactions

Additive effect with stimulants (caffeine component)

Dosage

Available as tea, liquid and solid extracts, and ointment

Cost

Prices vary widely for tea and extracts by brand and quality, but potentially as low as $5 to $18 for one-month supply; ointment pricing varies by pharmacy, currently in $250 range or higher for 15-g tube

Bottom line

Safe alternative to treat genital warts; inconsistent evidence for use in cancer prevention, cardiovascular disease and stroke prevention, and weight management