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The pre- and peri-implantation development of the human embryo remains poorly understood, limiting the improvement of the diagnosis and treatment of human infertility. Animal models have limited relevance, and human embryo research presents ethical and regulatory constraints. Blastoids, an in vitro embryonic model formed from human embryonic stem cells, have a very high morphological, molecular, and functional similarity to human blastocysts, and can be produced with high yield. They are therefore a very promising model of human embryonic development and implantation. The potential applications are numerous, from improving MAR results to ascertaining reproductive toxicity, while respecting the existing ethical and regulatory framework.