Green Tea and Drug Testing - EGCG and Morphine

I will be doing a drug screening test today to be a substitute teacher for one of our local schools. I take 300 milligrams of green tea extract a day for health purposes. I have never, ever taken any type of illegal drugs. Will the green tea have any bearing on this test? I have heard that it will make a test show positive for drugs. Is this true?


Hey, as far as I am aware, there is no evidence that green tea will influence drug test results. The major compounds in green tea are catechins, caffeine and theanine. None of them is associated wtih drug chemicals.

Interestingly, a 2007 study conducted by National University of Korea found that green tea active compound EGCG (epigallocatechin gallate) inhibits morphine withdrawal symptoms such as orepaw tremor, rearing, teeth chattering, urination, and wet dog shake.

In addition, EGCG reduced the morphine-induced increase in the cAMP levels in the locus coeruleus at 100 mg/kg and the signaling of the dopamine D2 receptor at 100 microM.

This study also shows that one has to take a large amount of green tea to have an impact. At 100 milligrams per kilogram, this translates to 7 gram of EGCG for a 70-kilogram human being. This is probably too much green tea extract for a human being to consume in any one day. So it remains to be seen how useful green tea can be in curing drug symptoms.

In conclusion, taking green tea could help drug addicts cope with withdrawal symptoms, but there is no evidence that green tea consumption would result in you being tested positive in tests if you have not taken any form of drug.


Oh KW, Eun JS, Kwon HN, Cho EY, Kim KM (2007). Effects of (-)-epigallocatechin gallate on the development of morphine-induced physical dependence. Arch Pharm Res. 2007 Sep;30(9):1111-5. College of Pharmacy, Chungbuk National University, Cheongju 361-763, Korea.

Comments for Green Tea and Drug Testing - EGCG and Morphine

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Jan 05, 2010
E.G.C.G. Test
by: Bill

It seems all tea vendors claim a high amount of egcg in their products. Is there an easy test to accurately determine amount of egcg?

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