A 2004 study found that how you treat your hair determines how long incriminating drug evidence can stay hidden amongst your strands.
The American Association for Clinical Chemistry conducted research to find how effective hair was in holding in “cannabinoids” and THC (the chemical that invokes that high feeling). Four differently treated strands of the same hair was subjected to an hour long marijuana session and then the strands were individually tested.
As always, the cleaner you are, the better it is for everyone.
If your hair is greasy and dry, it holds a lot more of the weed chemicals than if it’s clean and dry. Bleached and permed hair has a 20 percent increase in the number of cannabinoids held compared to natural hair because your hair is more broken and frayed.
The research found that washing your hair with methanol spirits reduced the evidence but in my opinion, it would make your hair brittle and strip away all it’s natural goodness. Unless you’re on an absolute paranoid trip, don’t do this.
As for drug testing in general, hair testing is the least favourite choice around the globe because it costs more than urine testing and requires a lab, although it provides a bigger window of detection. If you have long hair, they could find weed you smoked six months ago. The cool thing about hair testing is that even if you go full skinhead and shave everything, they can still find evidence in your hair follicles. Big Brother is Watching.
To read the full study, download it.
It’s funny how the healthier your hair is, the less “weed evidence” it holds. Gives you reason to be an all out hippy.
HOLYMOLY. Thats insane. Yes I did wash my hair with methanol spirits just to test your theory…..I have no hair now.
P. HA jokes luv jokes. Big Brother is Watching and he should just a life 
P.
wow… i never even THOUGHT about the traces that stay in your hair. scary.