Heron’s (HRTX) Zynrelef Gets FDA Nod for Label Expansion Posted byZacks Equity Research December 10, 2021 Leave a comment on Heron’s (HRTX) Zynrelef Gets FDA Nod for Label Expansion The FDA grants label expansion to Heron???s (HRTX) Zynrelef for pain relief after small to medium abdominal surgeries, lower extremity total joint replacements, and foot and ankle surgeries in adults.