I just began to use it. You get a roll on or a balm or straight essential oil you can mix with what is termed a carrier oil - i use sweet almond oil but olive oil is fine too.
I didn't have to wait long to test it - I turned into a door frame the next day carrying towels from the dryer and banged my forearm.
I mix it in a little plastic container with a lid intended for condiments. I try to mix a solution that is maybe 3 teaspoons all together - 2 tsps of carrier oil and one dropper of the essential oil. That is based on reading a lot about strengths. A lot of people report they just do full strength and i may work up to that.
You should test it on your arm - I put some in the crook of my elbow because it is less likely to get inadvertently wiped off there. Give it a while to make sure you don’t get hives or itchy, etc.

I am going to show two pics - one the day it happened and one four days later. I don't know how fast anyone else heals, but this event would typically take four weeks to fade. This seems significantly faster. One time is not proof and it isn’t magic but it is better than Arnica.