Warfarin & Green Tea
Green tea contains high vitamin k & can inhibit the effects of
There are many different grades of green tea, from bottled to canned to freshly
brewed green tea.
The best & most famous type of green
tea is Dragon Well (龙井茶) tea.
I had an opportunity to visit Mei Jia Wu –“Plum Family
Village", at Xi Hu (西湖) during a holiday trip to China in May 2007. My tour guide was a school
mate of the plantation owner’s son. Hence my tour group, including myself, had the priviledge of sampling very
high grade Dragon Well tea (龙井茶) for free.
Each of us was given a glass of about 200ml of Dragon Well tea
When I first started warfarin medication, nurses & doctors had
warned me against taking green tea as it was known to have adverse impact on the anticoagulation
Flashed back to May 2007, I could still remember the sweet aroma of
the Dragon Well tea (龙井茶), & the undescrible, refreshing taste when I had my first sip. Unable to resist the
great taste, I finished half of the glass before I knew it (when I had initially meant to take a sip
It was an unwise choice. About 10 minutes later, I broke into cold
sweat & felt the air becoming very thin.
I tried to take in more deep breath but it didn’t help.
I excused myself from the tour group & chose a less crowded area to rest. By now, my body had started to
shiver a little uncontrollably, & my hands were icy cold. I tried standing up, sitting down, walking a bit but
nothing helped. A while later, I was panting badly & feeling very ill. I panicked when I remained
breathless still & that my fingernails had turned light purplish.
There were a lot of wild thoughts racing in my mind then. I didn’t
want to be hospitalized in a foreign country, & whatever it was, I was kind of
I forgot how much time had passed. Seemed ages to me.
Slowly, my breathing became less laboured & I began to feel a little
better. Whatever it was (causing me the great
discomfort), the effects had eased over time.
About an hour later, after I had the half glass of green tea,
I was able to walk, though my knees still felt weak. I guessed my face might have looked pale as many
people there were staring at me. I had no chance to look in the mirror, so I wasn't sure how I had looked
As of today, I am still unable to apprehend what exactly had caused such
an adverse reaction in my case.
What I am certain is, after that terrifying experience, I have promised myself
that I would never take this potent drink again. The consequence was too much for me to bear, & I
hope no one else would go through the same experience which I have had.
One interesting point to note is, prior to my China trip, back in Singapore, I had
ever drank half a packet of green tea, or a third of a bottled green tea without such adverse impact. The
only reason I can offer is that, commercialised green tea drinks (e.g. packet or bottled green tea) may
have lost most of its potency during the manufacturing process. Freshly brewed & high grade ones
should be avoided at all cost.
My word of advice to other warfarin users - please
AVOID taking any high grade Dragon Well tea (龙井茶), or freshly brewed green