Winter can leave your immune system running low, making you more susceptible to coughs and colds. Bee Health Propolis Winter Liquid is a versatile way of accessing the benefits of this wonderful, natural ingredient. Propolis is a natural substance collected by honey bees from buds and trees containing tree resin, essential oils, waxes and bioflavonoids. Propolis offers an array of benefits for many ailments and is one of nature’s richest sources of bioflavonoids for immune support. Bee Health guarantees the bioflavonoids present are naturally occurring flavonoids, with no synthetic substances added. This unique natural substance is subject to tests for potency and quality.