The consistent, multi-day use of marijuana topicals at varying THC levels did not result in a negative drug test for any participant of a new study published by the journal Forensic Science International.
For the study, researchers used “two commercially produced products topically that contained 1.7ng and 102ng THC per mg, respectively”.
In an experiment; “three volunteers (25, 26 and 34 years) applied both types of salves” every two to four hours over a three day period. The application was “extensive (50-100cm2)”, and each volunteer applied the products “to different parts of the body (neck, arm/leg and also trunk, respectively).”
After the first application blood and urine samples of the participants were taken “every 2-4h until 15h after the last application (overall there was 10 blood tests and 10 urine tests conducted for each participant).”
All of these blood and urine samples were tested negative for THC, as well as 11-hydroxy-THC and 11-nor-9-carboxy-THC.
Researchers conclude; “According to our studies and further literature research on in vitro testing of transdermal uptake of THC; the exclusive application of (these two) topically applied products did not produce cannabinoid findings in blood or urine.”
The study was conducted at the University of Bonn’s Institute of Forensic Medicine in Germany. Click here for the full text and also abstract.