Tesco says its home delivery service is "maxed out" at the moment.
It is looking for people to consider whether they can make it to the shops themselves to free up space for those who cannot.
Chief operations officer Geoff Byrne says there is huge demand at the moment amid the Covid-19 pandemic.
"To be honest it's maxed out at the minute. People can't get slots," he said.
"What we will do is we would ask a lot of able-bodied, healthy people that probably could [to] get to a shop. We'd really like to free up slots where we can for over 65s."
- The HSE have developed an information pack on how to protect yourself and others from coronavirus. Read it here
- Anyone with symptoms of coronavirus who has been in close contact with a confirmed case in the last 14 days should isolate themselves from other people - this means going into a different, well-ventilated room alone, with a phone; phone their GP, or emergency department;
- GPs Out of Hours services are not in a position to order testing for patients with normal cold and flu-like symptoms. HSELive is an information line and similarly not in a position to order testing for members of the public. The public is asked to reserve 112/999 for medical emergencies at all times.
- ALONE has launched a national support line and additional supports for older people who have concerns or are facing difficulties relating to the outbreak of COVID-19 (Coronavirus) in Ireland. The support line will be open seven days a week, 8am-8pm, by calling 0818 222 024