High concentrations of catechins and caffeine in green tea extract can be harmful
A recent study by the American College of Gastroenterology concluded that green tea extract, a common ingredient in weight-loss pills, is unsafe and can cause liver damage.
It is best to get green tea benefits naturally.
Green tea extract is not regulated
Green tea extract supplements are regulated in the US and Europe as foods, not medicines. Specific safety testing has not been required.
https://www.bbc.com/news/stories-45971416
Taking green tea extract can impact overall health
Green tea pills can be effective for short-term weight loss. Side effects can negate that temporary loss in your waistline.
It is not just your liver. Other vital organs can be negatively affected by consuming green tea extract.
https://www.womenshealthmag.com/health/a19966040/green-tea-extract-supplement-organ-damage/
Supplements can be bad for the environment
Many supplements are petroleum extracts, coal tar derivatives, or chemically processed sugar, with other acids and industrial chemicals (like formaldehyde) used for processing. These compounds can be harmful to the environment and your health.
Japanese people drink green tea
They do not take green tea extract pills. For decades Japan has been at or near the top in longevity statistics.
Real Japanese green tea is healthy and invigorating!