Neuralink implanted the first brain-computer chip into a human patient, Elon Musk said in a post on X Monday evening.

Musk did not provide any details about the patient, only noting in the X post that the patient was “recovering well.” He added that initial results show “promising neuron spike detection.”

Brain-computer technology, otherwise known as brain-computer interface or BCI, involves implanting a device onto the surface of the brain which can connect its electrical activity with an external device like a smartphone or computer. 

The idea is for people who are paralyzed or unable to speak to be able to control movement and the use of computers with just their thoughts.

This has been a long time coming for Neuralink, which has been on a rollercoaster ride to this first implant. In mid-2022, it completed a $280 million fundraising round led by Peter Thiel’s Founders Fund.

In September, Neuralink said it was launching the first human trials for the brain implant — which would be focused on patients with quadriplegia due to cervical spinal cord injury or amyotrophic lateral sclerosis (ALS). 

The study, dubbed PRIME (Precise Robotically Implanted Brain-Computer Interface), would involve a robot to surgically sew an implant onto the brain that could then record and transmit brain signals to an app.

Shortly after the announcement, Musk added in another X post that the first Neuralink product would be called “Telepathy,” and it would enable “control of your phone or computer, and through them almost any device, just by thinking.”

“Initial users will be those who have lost the use of their limbs,” Musk explained. “Imagine if Stephen Hawking could communicate faster than a speed typist or auctioneer. That is the goal.”

The announcement of the first implant comes after Neuralink has faced scrutiny — especially over the past year — regarding safety concerns with the implants.

In a series of exposés published in 2022 and 2023, Reuters reported that Neuralink implants were responsible for the deaths of some 1,500 animals over the course of four years.

Neuralink was the subject of separate federal investigations by the Department of Transportation as well as the Department of Agriculture’s inspector general. The latter investigation found that the company did not violate animal research rules other than a previously reported 2019 incident.

Neuralink also faced several regulatory setbacks from the Food and Drug Administration, though the agency in May 2023 agreed to clear the company for human trials.

Neuralink isn’t the first or only company to explore BCI. Other companies, including Synchron, Precision Neuroscience and Blackrock Neurotech, have sought to commercialize products in the space. Blackrock Neurotech said it has managed to implant an older device into patients, helping them eat and use robotic arms just using their thoughts.

Despite the milestone implant news, plenty of users on X reacted with mocking, humorous responses about the dangers of brain implants, while others brought up some of the moral questions that come with the technology.