My limited experience (one version of sambuca made from star anise and one from elderberries) seems to indicate that the elderberries are far more effective at boosting the immune system. Star anise doesn't affect my ME, while the elderberry version made my symptoms seriously worse, as though my immune system was strongly activated. If I really needed an immune booster, I'd try the elderberry extract first (or the sambuca, though the star anise one tasted better).
One problem for me, if I wanted immune system boosting, is that many of the boosters are antioxidants or peroxynitrite scavengers, which make my symptoms worse.
One problem for me, if I wanted immune system boosting, is that many of the boosters are antioxidants or peroxynitrite scavengers, which make my symptoms worse.