Polyampholyte-based physical hydrogels exhibit high toughness and viscoelasticity, offering a versatile platform for structural biomaterials. These hydrogels are formed by random copolymerization of oppositely charged ionic monomers at high concentrations, resulting in a supramolecular structure with multiple ionic bonds of varying strengths. The strong bonds act as permanent crosslinks, while the weak bonds reversibly break and reform, enabling energy dissipation and self-healing. This unique structure allows the hydrogels to be tuned for a wide range of mechanical properties, including stiffness, strength, toughness, damping, fatigue resistance, and self-recovery. The hydrogels contain 50-70 wt% water, making them highly viscoelastic with a fracture energy of 4000 J/m², 100% self-recovery, and high fatigue resistance. They also demonstrate partial self-healing and shape memory effects, with mechanical properties adjustable by selecting appropriate ion combinations. The hydrogels are synthesized by polymerizing oppositely charged ionic monomers in a concentrated aqueous solution near the charge balance point. The resulting hydrogels exhibit a wide range of mechanical properties, with Young's modulus and damping ability tunable by ion selection. The hydrogels are non-toxic and anti-fouling, making them suitable for biomedical applications. They show excellent biocompatibility and anti-biofouling properties, as confirmed by cytotoxicity and adhesion tests. The hydrogels are highly versatile, with mechanical properties that can be adjusted to match the requirements of various applications, including load-bearing materials, surgical devices, and tissue engineering. The hydrogels demonstrate unique mechanical behavior, including high toughness, self-recovery, fatigue resistance, and self-healing. They are strongly viscoelastic, with high loss factor values and shock-absorption capabilities. The hydrogels also exhibit universal behavior as supramolecular materials, with properties dependent on the chemical structure and ion combinations. The hydrogels show excellent mechanical performance, with tensile fracture stress ranging from 0.1 to 2 MPa, fracture strain from 150% to 1500%, and work of extension at fracture from 0.1 to 7 MJ/m³. These properties make the hydrogels suitable for a wide range of applications, including structural biomaterials, medical devices, and hygiene products. The hydrogels are the first example of supramolecular hydrogels that demonstrate high toughness, offering a new approach for designing tough materials.Polyampholyte-based physical hydrogels exhibit high toughness and viscoelasticity, offering a versatile platform for structural biomaterials. These hydrogels are formed by random copolymerization of oppositely charged ionic monomers at high concentrations, resulting in a supramolecular structure with multiple ionic bonds of varying strengths. The strong bonds act as permanent crosslinks, while the weak bonds reversibly break and reform, enabling energy dissipation and self-healing. This unique structure allows the hydrogels to be tuned for a wide range of mechanical properties, including stiffness, strength, toughness, damping, fatigue resistance, and self-recovery. The hydrogels contain 50-70 wt% water, making them highly viscoelastic with a fracture energy of 4000 J/m², 100% self-recovery, and high fatigue resistance. They also demonstrate partial self-healing and shape memory effects, with mechanical properties adjustable by selecting appropriate ion combinations. The hydrogels are synthesized by polymerizing oppositely charged ionic monomers in a concentrated aqueous solution near the charge balance point. The resulting hydrogels exhibit a wide range of mechanical properties, with Young's modulus and damping ability tunable by ion selection. The hydrogels are non-toxic and anti-fouling, making them suitable for biomedical applications. They show excellent biocompatibility and anti-biofouling properties, as confirmed by cytotoxicity and adhesion tests. The hydrogels are highly versatile, with mechanical properties that can be adjusted to match the requirements of various applications, including load-bearing materials, surgical devices, and tissue engineering. The hydrogels demonstrate unique mechanical behavior, including high toughness, self-recovery, fatigue resistance, and self-healing. They are strongly viscoelastic, with high loss factor values and shock-absorption capabilities. The hydrogels also exhibit universal behavior as supramolecular materials, with properties dependent on the chemical structure and ion combinations. The hydrogels show excellent mechanical performance, with tensile fracture stress ranging from 0.1 to 2 MPa, fracture strain from 150% to 1500%, and work of extension at fracture from 0.1 to 7 MJ/m³. These properties make the hydrogels suitable for a wide range of applications, including structural biomaterials, medical devices, and hygiene products. The hydrogels are the first example of supramolecular hydrogels that demonstrate high toughness, offering a new approach for designing tough materials.