This study investigates the performance of three types of gel electrolytes—hydrogels, iongels, and eutectogels—as dielectric layers in organic electrochemical transistors (OECTs). The eutectogel, composed of poly(glycerol 1,3-diglycerolate diacrylate) as the polymer matrix and choline chloride combined with 1,3-propanediol as the ionic component, outperforms hydrogels and iongels in terms of transient and steady-state performance for both p-type depletion and p-type/n-type enhancement mode OECTs. The eutectogel-integrated enhancement mode OECTs exhibit exceptional operational stability, maintaining a consistent signal-to-noise ratio (SNR) over 5 hours of continuous operation and 30 days of daily measurements. These devices also show higher ECG signal amplitudes and SNR compared to those using a commercially available hydrogel. The eutectogel's high mechanical durability and nonvolatile nature make it suitable for long-term physiological signal monitoring. The study highlights the potential of eutectogels as a semisolid electrolyte for OECTs, particularly in applications requiring robust and prolonged physiological signal monitoring. The results demonstrate that eutectogels offer superior performance compared to hydrogels and iongels, with the best performance achieved using DES4 as the electrolyte. The study also shows that the performance of OECTs is influenced by the type of electrolyte, with eutectogels providing the best results in terms of stability, signal quality, and long-term operation. The findings suggest that eutectogels are a promising alternative to traditional aqueous electrolytes for OECTs, particularly in wearable and biomedical applications.This study investigates the performance of three types of gel electrolytes—hydrogels, iongels, and eutectogels—as dielectric layers in organic electrochemical transistors (OECTs). The eutectogel, composed of poly(glycerol 1,3-diglycerolate diacrylate) as the polymer matrix and choline chloride combined with 1,3-propanediol as the ionic component, outperforms hydrogels and iongels in terms of transient and steady-state performance for both p-type depletion and p-type/n-type enhancement mode OECTs. The eutectogel-integrated enhancement mode OECTs exhibit exceptional operational stability, maintaining a consistent signal-to-noise ratio (SNR) over 5 hours of continuous operation and 30 days of daily measurements. These devices also show higher ECG signal amplitudes and SNR compared to those using a commercially available hydrogel. The eutectogel's high mechanical durability and nonvolatile nature make it suitable for long-term physiological signal monitoring. The study highlights the potential of eutectogels as a semisolid electrolyte for OECTs, particularly in applications requiring robust and prolonged physiological signal monitoring. The results demonstrate that eutectogels offer superior performance compared to hydrogels and iongels, with the best performance achieved using DES4 as the electrolyte. The study also shows that the performance of OECTs is influenced by the type of electrolyte, with eutectogels providing the best results in terms of stability, signal quality, and long-term operation. The findings suggest that eutectogels are a promising alternative to traditional aqueous electrolytes for OECTs, particularly in wearable and biomedical applications.