I am having supply issues and have with all 3 kids. The other day, someone told me to drink red raspberry tea, and she said I should be able to tell as soon as overnight. I had heard of the tea for bringing on labor, but not for this, but she gave me some, and I gave it a try.
I have to say, my daughter seemed to be gulping and swallowing way more the next day.
I know pumping helps people, but it never seemed to "let down" when I pumped.
Good luck to you, let us know how it goes.