Speaking on BBC Radio Scotland's Call Kaye show the Edinburgh-born former international called on the NHS and government to do more to help those living with MND.
The 49-year-old said that no-one had ever beaten MND and told of his frustration that no difference is made around the timescales for progression of the illness.
Weir who was diagnosed almost three years ago was speaking after last week's emotional stage appearance at the Edinburgh International Book Festival where he hit out at the 'cut-throat' treatment of MND patients by the health service and spoke of his determination to live for as long as possible to see his children grow up.
He said: "My annoyance has to be that nothing has been done for the last 25 years - it is a terminal issue.
"When you're told you've got MND, you go home and you go and Google on the computer of how to try and rectify your issue on how to stay alive.
"It's a bit like you've got a broken arm and you're sent home to fix it yourself but with MND it's a much more serious condition because it's a terminal condition and no-one's actually beaten MND to date and that's my annoyance.
"The powers that be have done nothing over the last 25 years plus to bring any extra sort of drugs or help to the table.
"So there is no platform or pathway that helps.
"So for example - swimming, does it help?
"Does exercise help?"
The former Scotland and British Lions star whose charitable foundation is on the way to raising £4 million to help fund research projects across the UK and investigate possible cures, has previously said that the lack of drugs available to treat the condition across the country was "disgraceful".
He added: "Every patient has to look at their own self cure and I think a lot more could be done - through the NHS and the government as well.
"But the care and the individuals behind it are certainly helping everyone with MND and I thank them.
"The other statement I have said 'left to die' is very true in that once you are given you're diagnosis that's when the help of cure stops.
"There is no cure.
"There is no help but the care package continues.
"It's horrific what happens to people with MND so the care is there but the cure is not.
"You're told you've got MND - there's your care nurse - cheerio!
"And I don't think that's acceptable in today's environment."