The Good Morning Service, based in Springburn, previously covered only the north of the city but as part of its expansion it has been launched in South Ayrshire.
Health minister Alex Neil isited the project as the plans were announced, thanks to a £50,000 Scottish Government grant.
As part of the project, elderly people who sign up are given a call every morning, with additional night calls in winter, to make sure they are OK.
Staff at the Good Morning Service work to build relationships with those they call and if someone fails to answer the phone or they seem unwell, they can raise the alarm.
The staff hold details of next of kin and GPs and they and will follow up an unanswered call until they locate the person and know they are safe and well.
Police Scotland is also alerted if someone cannot be found and their safety verified.
Last year staff discovered four people who had fallen at home and one person had suffered a stroke. Emergency services were alerted and they were taken to hospital.
The average age of a member is 81 but people can join from as young as 60.
Nicky Thomson, chief executive of the Good Morning Service, said: "Our older people have overcome many challenges throughout the years and now it's time for us to say thank you, by providing those who need a helping hand with the light-touch support from Good Morning Service.
"Members feel safer knowing that potential problems will be picked up, they are connected to the Good Morning community and in turn to their wider community, but most importantly they feel valued as a worthy human being by being really listened to by someone who cares. Our motto is that five conversations a day are as important to your health as five portions of fruit and veg."
She added: "We're delighted to have the health minister launch our new South Ayrshire service and expansion across Glasgow."
The service was first launched in 2000 for the Milton area. It grew to cover north Glasgow but is now available to all in the city. Staff say the calls help older people feel more secure in their homes and can also improve their confidence.
One 76-year-old service user said: "My call boosts me up and makes me want to get ready and go out even if it's just a wee walk round the shops.
"I've made a lot of new friends to blether to.
"And it's a great feeling to go to bed and know if I take ill during the night they are always there to help - it's security."
Another, aged 94, added: "It makes you live your life because you are never really on your own.
"They make me feel like a person - not an old woman. I can discuss things like politics and keep in touch with the world - they just keep me going."
To join the Good Morning Service call Andy or Laura on 336 7766 or 0333 101 0036.