The Voynich Manuscript remains undeciphered despite extensive cryptographic and linguistic efforts. This paper proposes a functional interpretation of the manuscript as a cyclical medical–astrological atlas rather than a linguistically encoded text. It argues that the manuscript’s imagery, textual elements, and zodiac diagrams form an integrated system for representing physiological, botanical, and temporal cycles, particularly those related to female fertility and lunar timing. The text is interpreted not as a natural language or cipher, but as a non-linguistic marker system identifying phases, transitions, and prohibitive states. By situating the manuscript within medieval medical, botanical, and astrological traditions, the study offers a coherent and testable interpretive model that accounts for all major sections of the manuscript without requiring decipherment.