Improved Formula Nutritive Support for Healthy Leg Circulation Horse Chestnut Formula Guaranteed Potency Dietary SupplementWhat Is Venastat?. The Venastat formula is a natural supplement that is intended to provide nutritive support for tired legs and leg vein health and circulation. What makes Venastat special. Venastat's HC167 Horse Chestnut extract is standardized to 16.7% Escin to provide a consistent level of extract in every easy-to-swallow capsule. This is a level of standardization used....