Claude Fable 5 Biology Safeguards Update

Fable 5 now answers everyday health and biology questions it used to refuse or hand off.

Anthropic's own testing showed the number of biology questions Fable 5 refused or handed to another model dropped about 85% across its products
Requests Anthropic treats as dual-use, including virology, toxicology, and molecular design, still get passed to Opus 5 instead of being answered by Fable 5
Because of that handoff, Fable 5 still is not usable for professional biology research or drug development
Anthropic says it plans to open frontier biology capabilities through vetted access pathways rather than by loosening the model's default behavior