United lost 1-0 to Newcastle United on Saturday to suffer back-to-back home defeats for the first time since 2002.
The reigning English champions are also 13 points adrift of Arsenal at the top of the Premier League, but Moyes insists that he will not be pressured into signing new players.
"In any transfer window you don't want to be bringing in a full batch of players, so I think there's a period of time that it takes," The Mirror quotes him as saying.
"I don't think I'll feel under pressure personally to do it (buy in January) as I'll try to do the right things.
"I tend to take my time and try to assess what are the best talents to bring in. You can see that from the players I brought in at Everton."