This article is part of a research work on non-binary genders and gender fluidity within everyone. The ideas that emerge are drawn from scientific readings and accounts given by those in question. Their realities are highlighted in order to clarify the issues of specifically non-binary identifications, for them and more generally for any person questioning their gender assigned at birth, in particular when a medical setting is involved. A political term, the phrase ‟non-binary” brings to light feelings which go beyond the strict framework of men and women and require, through this radical statement, a social questioning. It also accounts for the experience of identity all human subjects are confronted to in their search for themselves facing alterity that alienates them and sets in motion a creative process. Individual realities are thus very diverse and require, especially on behalf of health professionals, an enlightened reading of the reference texts and a reflection on the relevance of these concepts in their practice.