We’re updating Claude Fable 5’s biology safeguards to reduce false positives. In our testing, this update reduced biology-related fallbacks by about 85% across our product surfaces.

Fable can now assist on a wider range of everyday health and educational questions.

We believe the biggest positive impacts of AI will be in biology and medicine, and we’re committed to putting frontier intelligence safely into the hands of as many researchers as possible. Fable will continue to fallback to Opus 5 for requests we consider dual-use—including virology, toxicology, and molecular design—so it isn't yet usable for professional biology research and drug development.

We're committed to closing that gap through trusted access pathways for frontier biology capabilities.

https://www.anthropic.com/news/improving-fable-5-s-biology-safeguards