Histamine Block only acts on histamine contained in foods within the digestive tract. It is not intended to have systemic effect.
We do offer a product called HistaminX, which is designed to help support mucus membranes and seasonal comfort. It may also help support a healthy immune system, which is important for managing any kind of allergy - however, we are not able to make any claims regarding its effects on other histamine-induced allergy symptoms.*