I'd not heard of it before but it looks as if it's apple cider vinegar (with the mother), natural ginger and garlic juice.
They have it on iHerb btw. There are reviews there if you want to read them.

Try eating more of foods like kumara, avocado, papaya and lentils.

I don't get leg cramps but have had restless leg syndrome most of my life on and off and I find magnesium helps (as well as a few other little tricks I've learned to help keep at bay.