R3 Bio is actively developing technology to grow headless human bodies known as "bodyoids."

These genetically engineered structures contain full organ systems but lack a brain, rendering them nonsentient and incapable of feeling pain.

The Bay Area startup's project is accelerating as President Trump phases out federal animal experimentation across government agencies.

R3 Bio's long-term goal is to create human versions that serve as a direct source of tissues and organs for people who need them.

Immortal Dragons CEO Boyang Wang, whose Singapore-based longevity fund backs the company, stated: "If we can create a nonsentient, headless bodyoid for a human being, that will be a great source of organs."

For now R3 Bio is focusing on monkey organ sacks.

These would replace live monkeys in drug toxicity testing, providing scalable models with complete organ complexity including blood vessels.

The company uses stem-cell technology combined with gene editing to disable brain development while allowing organized organ growth.

Cofounder Alice Gilman said the approach eliminates the ethical issues of pain and suffering in animal research.

R3 Bio was inspired in part by organ shortages.