Artificial intelligence (AI) is transforming medical writing by supporting scientific publishing, regulatory documentation, and clinical research communication. Advances in machine learning, natural language processing, and large language models enable AI-assisted literature retrieval, evidence syn thesis, manuscript development, language editing, quality control, and regulatory document preparation. AI is increasingly used to support clinical and regulatory document development, improving efficiency, consistency, scalability, and workflow management through automation and content standardisation. However, challenges remain, including inaccurate or fabricated content, bias, limited explainability, data privacy concerns, intellectual property issues, and the need for accountability and human oversight. This review examines the technological foundations, applications, benefits, limitations, ethical considerations, and regulatory expectations associated with AI in medical writing, as well as the evolving role of medical writers. AI has significant potential to enhance scientific and regulatory communication, provided robust governance, transparency, and expert human review support its use.