Great-tasting liquid iron formula to support hemoglobin and myoglobin function | Pure Encapsulations Iron liquid contains SunActive Fe, a micronized water-soluble form of iron with high bioavailability. Research indicates SunActive Fe iron pyrophosphate bioavailability is similar to ferrous sulfate. In a 16-week randomized, double-blind, placebo-controlled study involving 122 women, supplementation promoted healthy iron status, including hemoglobin, ferritin, and transferrin saturation. A blend of cranberry and blueberry fruit extracts offers antioxidant protection and additional microvascular support.