Chewing coca leaves and drinking coca tea is common in Peru, especially in the Andes. It is legal and is frequently recommended as a means to prevent altitude sickness (although its effectiveness is unproven). The problem, however, is the coca alkaloid content of coca, which may cause a drug test to show positive for cocaine. So, if there’s a possibility you might have a drug test when you return home from Peru, be careful with any form of coca consumption while on holiday.
Drinking Coca Tea Results in Positive Drug Test Outcomes
The 1995 study, the “Identification and Quantitation of Alkaloids in Coca Tea” by Forensic Science International, authors Jenkins, Llosa, Montoya, and Cone warn coca tea drinkers of the potential risks of positive drug tests after consuming the tea:
This study has shown that consumption of one cup of coca tea results in detectable concentrations of cocaine metabolites in the urine for at least 20 h. Therefore, coca tea drinkers may test positive in a urine drug test for cocaine. (“Identification and quantitation of alkaloids in coca tea”; Jenkins et al; 1995)
According to Amitava Dasgupta in Beating Drug Tests and Defending Positive Results: A Toxicologist’s Perspective Amitava Dasgupta; Humana Press; 2010, "like decaffeinated coffee, residual cocaine may still be present after “de-cocainization” of coca leaves.” Even coca teas that are supposedly free of cocaine may result in a positive drug test.
Dasgupta recommends greater caution regarding coca teas and drug tests: “Because of the possibility of testing positive for cocaine following drinking coca tea, it is advisable to avoid any herbal tea originating from South America at least for a few weeks prior to any workplace drug testing.”
Chewing Coca Leaves Results in Positive Drug Test Outcomes
Less research seems to exist about the precise risk of chewing coca leaves (rather than drinking them in a tea) prior to a drug test. But it seems reasonably safe to assume that if drinking coca tea can result in a positive drug test than so too can chewing large amounts (or perhaps even small amounts) of coca leaves.
If a workplace drug test is a possibility, therefore, you should certainly consider avoiding chewing coca leaves in the weeks leading up to the potential test.
Bringing Coca Leaves and Coca Tea Into the United States
Thinking about bringing some coca back into the U.S.? Think again. It should come as no surprise that coca is a controlled substance, and according to the U.S. Department of State:
Although coca-leaf tea is a popular beverage and folk remedy for altitude sickness in Peru, possession of these tea bags, which are sold in most Peruvian supermarkets, is illegal in the United States.
The same is true for many countries, including the United Kingdom, whose government offers the following travel advice for Peru: "Don’t take coca leaves or coca tea out of the country. It’s illegal to import these items into the U.K."