A study of 1.19 million biomedical papers on PubMed Central shows generative AI is rapidly used in academic writing, with 77% of papers showing AI assistance by 2025, up from 19% in 2023 and 52% in 2024. The discussion section has the highest AI usage rate at around 78%, followed by abstracts at 68%. Researchers from non-English speaking countries use AI at over 80% compared to around 63% in English speaking nations. The technology helps improve grammar and expression but also risks creating false facts and missing references, with some authors failing to disclose AI use. Experts call for guidelines rather than bans, proposing requirements for fact checking, reference verification and AI disclosure to set reasonable usage boundaries.