I had transplant my hair it is the 8th day after. Is it ok if I smoke weed??

Smoking is generally bad for you.  However there is no data on if smoking will affect your surgery results. 

There is no data supporting a conclusion either way in regards to marijuana however smoking cigarettes is a different problem and IS supported by data. Heavy smoking can cause delayed healing and even a decrease in yield if the patient already has a circulatory issue.

It is never "ok" to smoke weed.  Having had a hair transplant 8 days ago does not change this one way or the other. 

Smoking anything is not recommended when you are healing, and there is also no data that shows THC or other marijuana compounds will inhibit hair growth.  I would call it a small risk and generally advise against it.
Good Luck!

At 8 days, smoking is never a good idea but I don't see a problem if you were my patient.  Many people do what you nare asking

You can smoke marjuana after seven days, as aling as you have stopped take ng your pain medication pills. If you are still taking them then you need to wait. Also check with your own doctor.