These bumps are they external or...?
Like pimples or...?
The soy protein maybe a bad idea, reason is that some research has shown that their are female hormones and precursors to these hormones in the product, everybody biochemical reaction is different but, why take the chance.
Even though this shows up during her cycle, take a good hard look at the diet, alot of conditions are from food allergies.
Grandpa, who was a Chiropractor too, alway said, "allergic reactions must be sweated out, do you like to run?"
As far as a topical agent, depending on a more desciptive account of these bumps, remeber this:
Oils will provide moisture and sometimes fuel a surface outbreak.
Drying agents such as alcohol, astringents, etc. have a drawing/drying affect, this is why things like acne cleansers are marketed so well, they dry the skin, in turn causing the skin to produce more oil, making the user fell greasy, who uses more product...