When you get a charley horse, massages, stretching, warm baths, and ice are all generally recommended (although none are scientifically proven to work). Those who want relief in pill form
can try vitamin B12 supplements."
I've had this under the left breast pain for 10 days now and although the intensity of the pain varies it hasn't totally gone away at any time. I'll be trying the suggested muscle cramp remedies to see if they can provide some lasting relief.