This article is a criticism of the idea of human “biological insufficiency” in transhumanism. The revelance is caused by the significance of the biological side into understanding of human nature and its development prospects. Methods: The basic methodology of research is dialectical approach, which allows to present the essence of human as a profound unity of the social and the biological that exist in the process of co-evolutionary development. There is also the use of several specific approaches in anthropology and human biology for more complex analysis. Conclusions: It is shown that transhumanism radicalizes real limits of human biology to justify the necessity of its fundamental “enhancement”. Transhumanism connects it with direct intervention of technologies in human body or with transformation of the genetic apparatus. Criticism of the idea consists in that scientific facts demonstrate only relative character of “insufficiency” of human biology. Consequently, it can be compensated by further progress of medicine, its transition to personalized form. It makes transhumanist approach to human biology overabundant. Application: The results can be applied to the analysis of alternative scenarios of development of human and its biology, the prognostication of this process.