Wild Lettuce (Lactuca virosa) organic herbal resin extract from Latvia:
This is the product I used. It took 2 grams made into a tea with honey to stop my headache. I weigh about 200 lbs, so a gram for every hundred pounds was the dosage that worked for me.
I would suggest that as a start till you find out what works for you.
The first time I tired it for an injury I had many months before a half gram did nothing at all for me, so I figured it was worthless. I was seriously wrong! It works and eliminated all of my pain 100%, unlike the synthetic narcotic crap I was using that gave me maybe 15% pain relief after using the 5th or 6th percocet 5 mg tab I had taken over a 2 week period when the pain became unbearable!
Note, there are many products on the market made with WLO: dried extracts, dried powders, alcohol and glycerin, tinctures, tar, etc.. I can not attest to their efficacy, since I have not tried them. The tar from Latvia is what worked for me.