I remember the last time I had a hair test.
I guess it all depends on what they are looking for.

Weed is the thing that stays in your system the longest.

If I recall, 3 months and your are clean from weed.

I had smoked weed just about 3 months before the test and I came up clean.

I had done coca and heroine about a month before the test and nothing happend.

Again, I don't know what they were testing for but I passed the test and got the job.

Good luck.

You can always shave everything including your eyebrows and you can tell them you are part of the Zab Judah cult.