Greig, who plays Jackie Goodman in Friday Night Dinner, told The Guardian that she thinks it is important to accept the ageing process.
When asked if she would contemplate Botox or similar procedures, the actress said: "No! I'm an actor and I'm supposed to reflect real people. I think it's dishonourable to women, I think you just have to be the age you are and live with it.
"You just have to engage with the little deaths, otherwise we just don't know how to do the big death. I'm not saying these things are easy, or I do this lightly, but you have to make a proper decision about things."
Greig also said that she found it "quite funny" when a woman suggested she should have Botox while starring in David Hare's play Gethsemane three years ago.
Friday Night Dinner airs on Friday nights at 10pm on Channel 4.