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Facebook shares tumbled on Wednesday after the social media network's revenue and user growth fell short of investor expectations.
The firm, which is facing backlash for its handling of fake news and privacy, said it had 2.23 billion monthly active users at the end of June.
That was up 11% compared to 2017the slowest growth in more than two years.
The firm reported revenue of $13.2bn for the three months to the end of June, up 42% year-on-year.
But expenses grew even faster, rising 50% to about $7.4bn.
Shares in Facebook fell about 8% in after hours trade in New York.
Facebook had said it planned to spend more heavily as it responded to criticism of how it monitors content on its platform and protects user data.
"Our community and business continue to grow quickly," said Mark Zuckerberg, Facebook founder and CEO. "We are committed to investing to keep people safe and secure, and to keep building meaningful new ways to help people connect."
The firm said profits in the quarter were $5.1bn, up 31% from the same period in 2017.