To add to others, Symphytum officinale. Especially extract processed to gel works pretty nicely. Longest used combination is with Camphor. Good for light to medium muscle and joint aches. Good for high volume treatment after exercise and training. For Manga/Light novel readers, this combination was used in Spice and Wolf to treat Holo's back and Kraft's face injury.
It's great, it works both for muscle and joint aches and for healing broken bones too.
Apart from other effects, it positively triggers accelerated cell division for faster healing.
However, it's known to be toxic during prolonged usage. Wikipedia lists liver damage.
Increased cell division also means higher risk of cancer when taken regularly in high volumes.
One time exposure for max 4-5 days are ok, then there should be pause at least 2-4 week without exposure.