I would suggest seeing a primary doctor to make sure that your electrolytes aren't out of balance.

Do you drink enough water during the day?

Cramping muscles can be from increased MG weakness as well.

I would not use astragalus as a way to wean off of Pred! That herb can reduce the effectiveness of immune suppressant drugs, including steroids.

First find out what is going on with your body, by having some basic tests like a chem panel and CBC done. Then allow your docs to figure out a good course of action. Experimenting on the body can be quite dangerous. Simply because an herb is "natural" does not mean the effects are benign!

I can appreciate wanting to find alternative medicine for MG. But there has not been sufficient research on anything for us.

I hope you can find a safe way to taper off of Pred (small doses at a time like 1 mg.).

Annie