My books on medicinal herbs state that goldenseal affects circulation,
muscle tone and uterine contractions.  It is also an antiseptic and
antibiotic.  Precautions include over-use because it can be toxic
in large doses.  It shouldn't be used if you have high blood pressure
or heart disease.  It doesn't say anything about lactating women.  (If
an herb is thought to be unsuitable for pregnancy and/or lactation, it
says so.)  As far as I know, goldenseal is used mostly externally
anyway.

Susan Nachman-Srebrnik
Ranana, Israel