Can someone please help identify this plant?

We were given this as a cutting because it has medicinal properties, but have forgotten its name.

Characteristics include:

It flourishes and grows very fast... almost like a weed!

It grows into a bush, not a tree.

It's leaves are slightly fleshy; they're covered with some very light fuzz making them soft to touch; the leaves also carry a strange mild odor.

I know it's not mint.

Would very much appreciate someone identifying this for us.

Thank you in advance!