Aim: To investigate the effect of succinic acid on the humoral component of the immune system in rats. Materials and Methods: The study was conducted on two groups of mature non-linear white rats (males) of similar weight (200-270 g, aged 6-8 months), with 5 animals in each group. The control group was fed a standard diet with free access to water throughout the experiment. Rats in the experimental group were subcutaneously injected with a 0,1% solution of succinic acid in a liposomal emulsion at a dose of 20 cm³ for five days. The state of the humoral component of the immune system was assessed by measuring serum immunoglobulins A, M, and G using solid-phase enzyme-linked immunosorbent assay. Circulating immune complexes were determined in a 40% solution of polyethylene glycol. Results: Under the influence of succinic acid in liposomal emulsion the content of class A immunoglobulins increased by 44,0% (p<0.01) compared to rats in the control group. The activation of class A immunoglobulin synthesis points to the provision of local immunity of the mucous membranes in the rat's body. The content of class M immunoglobulins increased by 61,0% (p<0.001) compared to the control group rats. This high activity of class M immunoglobulins indicates their rapid activation in the body of rats in response to primary contact with succinic acid in liposomal emulsion. The content of class G immunoglobulins increased by 36,0% (p<0.05) compared to the control group rats. No clinical deviations from physiological norms were observed in the rats after the use of succinic acid in liposomal emulsion. After the use of succinic acid in liposomal emulsion in the experimental group of rats, the concentration of CICs increased by 15,0% (p<0.05) compared to the control group rats. In our case, the increase in CIC levels is not correlated with clinical manifestations but is a consequence of increased levels of class M and G immunoglobulins. Conclusions: The succinic acid in liposomal emulsion activates the production of class A, M, G immunoglobulins, circulating immune complexes, it prevents the development of secondary immunodeficiency and has a positive impact on the humoral branch of the immune system in rats.