Neuralink Criticisms and Controversies: The Full Story
- Neuralink's animal testing drew reports of complications, a USDA inspector general investigation, and an FDA inspection that found record-keeping problems at its own lab.
- The FDA rejected Neuralink's first request to start human trials in 2022 before clearing them in May 2023.
- Critics have also questioned workplace safety, data privacy, and the gap between Elon Musk's predictions and trial results.
Neuralink has faced public scrutiny on several fronts, as other new medical technologies have. This article sets out the main criticisms and how the company responded.
Animal welfare controversies
Development of the N1 implant began with monkey testing at UC Davis, and reports published from 2022 described surgical complications and euthanasia in those studies. Reuters reported in December 2022 that about 1,500 animals had died in Neuralink's testing since 2018. These incidents prompted a USDA inspector general investigation, and lawmakers asked the SEC to investigate Musk's statements about monkey deaths.
Neuralink now does its animal research in its own facilities, under Institutional Animal Care and Use Committee oversight. An FDA inspection of Neuralink's California animal lab in June 2023 found record-keeping and quality-control problems; the FDA said they warranted voluntary fixes rather than regulatory action, as Reuters reported in early 2024.
FDA scrutiny and early regulatory hurdles
The FDA rejected Neuralink's first application for human trials in 2022, citing risks that included the lithium battery, the possibility of the wires migrating in the brain, and how the device could be removed. Neuralink addressed those concerns, and the FDA cleared human trials in May 2023.
Neuralink has since received Breakthrough Device Designations for its device-control implant, for Blindsight vision restoration (September 2024), and for speech restoration (May 2025). By October 2025, 10 US implants and expansions to Canada and the UK had followed. Neuralink reported zero serious device-related adverse events as of January 2026, and a paper on the first three participants was submitted to the New England Journal of Medicine.
Many of the first participant's threads retracted in 2024. Software changes restored and then improved his performance even though most threads had retracted, according to Neuralink.
Employee concerns
Whistleblower accounts described pressure to move fast in animal studies, and a 2024 lawsuit over workplace safety involved a pregnant employee who worked near infected monkeys. The lawsuit settled with policy upgrades. Neuralink has since hired specialists in neurology and robotics and raised a $650 million Series E in June 2025.
FDA staff cuts in February 2025 included people who had reviewed Neuralink, but the cuts did not halt the trials. Interest from patients has grown: Jon Noble, a UK participant, wrote in December 2025 that more than 10,000 people were on the US waiting list.
Privacy, ethics, and hype
Critics have raised mental privacy fears and questioned Elon Musk's broader claims about cognitive enhancement and who will be able to afford it. The implant processes signals on its chip and sends them over Bluetooth to the participant's paired device. Neuralink's privacy policy says data from clinical trials is governed by the trial protocol and each participant's informed consent.
The medical results are what the company points to in answer: Noland Arbaugh games and studies on his own a year after his implant, and Neuralink participants have set a brain-computer interface record of 11.32 bits per second.
This article was first published in October 2025 and corrected in October 2026; the latest patient count is on the patient table.
