Amazon said Wednesday that it had completed its $3.9 billion acquisition of health care provider One Medical after the US Federal Trade Commission indicated it wouldn't challenge the merger.

Amazon said the acquisition, which was announced in July, will boost expand the primary care services Amazon is already offering through its Amazon Care brand, which includes prescription-delivery service Amazon Pharmacy and message-based telehealth service Amazon Clinic.

One Medical runs a chain of more than 150 primary care clinics in over a dozen US cities and offers online and mobile services to more than 800,000 individual subscribers as well as workers who receive its benefits from employers.

"Customers want and deserve better, and that's what One Medical has been working and innovating on for more than a decade," Amazon CEO Andy Jassy said in a statement. "Together, we believe we can make the health care experience easier, faster, more personal, and more convenient for everyone."

The deal's closure comes a day after antitrust regulators said they wouldn't sue to block the takeover but would still probe the acquisition. "The commission will continue to look at possible harms to competition created by this merger as well as possible harms to consumers that may result from Amazon's control and use of sensitive consumer health information held by One Medical," FTC spokesperson Douglas Farrar said in a statement to the media.

Lawmakers and regulators have expressed concern over possible monopoly power that Big Tech companies have. The FTC is also reviewing Amazon's $1.7 billion acquisition of iRobot.

After launching Amazon Care in 2019, the company followed up in 2020 by launching its own online pharmacy. Amazon Pharmacy fulfills prescriptions for people with or without insurance, and delivers them to customers' homes. Prime members receive special savings and free two-day shipping.