I did some research and found that oregano oil and other "volatile oils" cannot be taken during pregnancy. Also, herbs containing berberine like goldenseal and oregon grape are not safe during pregnancy and breastfeeding. Another that can't be taken during pregnancy is licorice root - bummer, as this is one of my best-working supplements!

I did find that lysine, blue-green algae and echinacea are safe.

Note to Backpacker - I couldn't find anything specific on red marine algae other than generic warnings like "contact your physician." Any suggestions?