Regarding
https://twitter.com/zev_dr/status/1304019820707487745
as mentioned there it turned out that green tea can also do the trick, let the water boil, wait for 1,5 - 2 minutes cooloff, then brew the tea for NOT LONGER than 5 minutes. This way, you will get the highest concentration of the main ingredient EGCG, here:

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Flavonoids are well bioavailable with > 15% [1]. Preparation in water can lead to a 50% loss of water-soluble flavonoids. A temperature of 85 °C is suitable for optimal brewing of green tea. After only 3 minutes, the EGCG content of 50.69 mg/100 ml is at its highest [4]. In a study it was found that the contents of epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate increase within the first 3 to 5 minutes.
With the duration of the infusion time, the content of epicatechin, epicatechin gallate and epigallocatechin gallate in green tea decreases [5].
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Here is an overview of the best way to achieve the appropriate temperature:
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Water temperature

The water temperature can also be roughly determined without a thermometer. The later the water is used for infusion after boiling, the lower the temperature of the water.

As a rule of thumb:
Water temperature directly after boiling about 95 °C (black tea, fruit tea, herbal tea)
Water temperature 1 to 2 minutes after boiling about 80 °C (Oolong tea, yellow tea, white tea)
Water temperature 3 to 4 minutes after boiling about 70 °C (green tea, yellow tea, white tea)
Water temperature 8 to 9 minutes after boiling about 60 °C (Japanese green tea)
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Always COMBINE this with zinc, as zinc is the key here.

You can use the tea leafs for a second brew, but you will not get the EGCG with the second brew, so just drink it for pleasure :-)
(and to use the green tea to the max, as there will be other valuable substances in the 2nd brew :-))