Peptides are often treated like supplements you can stack for convenience. One for repair, one for metabolism, one for inflammation. That mindset leads people to assume they can simply mix peptides in the same syringe and inject once. The problem is peptides are not pills. They are fragile, information-carrying molecules whose behavior is governed by physics, chemistry, and biology at the same time. A peptide is not just a chain of amino acids. In solution it exists as a three-dimensional structure held together by weak forces like hydrogen bonds, electrostatic interactions, and hydrophobic effects. These forces are highly sensitive to the environment. Small changes in pH, ionic strength, or solvent conditions can change the peptide’s shape, stability, and behavior. When a peptide is manufactured, it is stabilized in a very specific formulation. That formulation controls pH, charge, ion balance, and solubility so the peptide stays folded correctly and remains biologically active. When you mix two peptides together, you destroy that controlled environment and create a new, untested chemical system. One of the first things that goes wrong is charge balance. Peptides carry electrical charge depending on pH. That charge helps keep molecules from sticking to each other. Mixing peptides can shift pH just enough to reduce repulsion between molecules. When repulsion drops, attraction wins, and peptides begin to stick together. Ionic strength matters too. Mixing solutions often increases ion concentration, which compresses the electrical “buffer” that keeps peptides apart. This allows molecules to drift close enough for hydrophobic regions to interact. Water dislikes exposed hydrophobic surfaces, so peptides clump together to lower free energy. This is basic solution physics. Once aggregation starts, it accelerates. A few misfolded molecules form a nucleus, which seeds further aggregation. Early clumps may be invisible, but they still matter. They reduce the amount of active peptide, alter absorption, and change signaling behavior.