
The system is accessed via Facebook’s Help Centre where the use of search terms provided by Samaritans automatically direct users to a form where they can report friends in need to the charity.
Facebook notifies the Samaritans who can then contact the person and offer assistance.
Alongside the Help Centre link, Samaritans is running an awareness campaign to highlight its work and recruit volunteers by asking the UK’s 30 million Facebook users to Like its page.
Catherine Johnstone, chief executive of Samaritans, said the organisation was "harnessing the power of friendship so people can get help".
She added: "We want to remind people that if a friend says that life isn’t worth living, they should always be taken seriously. Facebook is a part of daily life for so many of us and we must make sure that people online have support when they need it."
Samaritans provides confidential support via 18,500 volunteers who respond to five million calls every year.