Zinc sulfate and zinc oxide are the most common forms in multivitamins. They are also the forms with the lowest absorption rates and the highest likelihood of causing nausea.
Zinc bisglycinate is a chelated form where zinc is bound to two glycine molecules. This chelation protects zinc from interacting with other minerals in the digestive tract — particularly important because calcium and iron can block zinc absorption.
Studies show zinc bisglycinate has approximately 43% higher absorption than zinc gluconate and significantly better gastrointestinal tolerance. At 22mg per serving — 2X the daily value — ZENYVA delivers meaningful immune support in the form your body can actually use.