The research was aimed at examining the safety of pantohematogen, which is produced from velvet antlers of the Altai Wapiti and is used as a functional ingredient in a range of supplements. Wistar rats (males and females) were injected with pantohematogen intragastricly in the maximum dose possible. During a six-month-long study, the influence of pantohematogen on the overall well-being, weight, peripheral blood, bone marrow, liver, kidneys, central nervous system, and cardiovascular function was examined. Throughout the experiment, the rats behaved as usual, their skin, hair, and appetite remained normal, reflexes were preserved, and the digestive and excretory systems were functioning properly. Therefore, no manifestations of the toxic effect of pantohematogen, administered intragastrically, were observed. The findings of the study revealed that doses of 250 and 500 mg/kg of pantohematogen led to increased liver weight, as well as decreased testicles in the male rats (the condition remained 2 weeks after the end of the administration). Examination of other internal organs in all experimental groups did not reveal any pathology when compared with the control and the intact animals. The doses of pantohematogen used in the experiments exceeded the doses for humans (per 1 kg of weight) by 2, 10, and 20 times. The findings of the study revealed no toxicity of pantohematogen. The study was performed at Tomsk National Research Medical Centre of the Russian Academy of Sciences and supervised by Suslov N.I., Doctor of Medical Science.