The speciation of epinephrine (Eph−) in the presence of alginate (Alg2-) and two biological and environmental relevant metal cations (Cu2+, UO22+) was investigated atT= 298.15K,I= 0.15–1.00 mol dm−3in NaCl(aq). The formation of binary and ternary complexes was evaluated and, since epinephrine can behave as a zwitterion, theEph−/Alg2-interaction was studied by means of DOSY NMR. The dependence of the equilibrium constants on ionic strength was studied using an extended Debye-Hückel type equation and the SIT approach. The effect of temperature was investigated by means of isoperibolic titration calorimetry: the entropic contribution was the driving force for the Cu2+/Eph−complexes formation. The sequestering ability ofEph−andAlg2-on Cu2+, evaluated by the pL0.5calculation, increased with pH and ionic strength. The determination of pM parameter showed thatEph−had a higher Cu2+affinity with respect toAlg2-. The formation ofEph−/Alg2-species was also investigated by UV-Vis spectrophotometry and1H NMR measurements. The ternary Cu2+/Eph−/Alg2-and Cu2+/UO22+/Eph−interactions were also studied. The “extra-stability” calculated for the mixed ternary species confirmed that their formation was thermodynamically favorable.