The Hyaluronic Synergy Ampoule by Iancell-L does not explicitly mention the acid percentage in the provided reviews. However, based on the reviews, the product is praised for its hydrating properties and gentle formulation, which suggests it may contain a balanced level of acids suitable for most skin types. If you are concerned about the specific acid percentage, it would be best to check the product's ingredient list on the official website or packaging for detailed information.