Since Hughes replaced Neil Warnock in early January the Loftus Road club have taken just four points from six league matches, leaving the 17th-placed side out of the relegation zone on goal difference only.
Moyes believes not every new manager could have an instant impact, and said: "When a new manager comes in you can sometimes get the instant effect of winning a few games like Martin O'Neill (at Sunderland). But in other situations it takes time to get results and bed in what you are trying to do."
He added: "But there is no right way and wrong way because if that was the case chairman would be changing managers every three months just to get an instant hit.
"It is one of these things: I am sure in time Mark Hughes will prove his ability as a manager at QPR.
"I am maybe not surprised (at their league position) because you wouldn't expect a newly-promoted team to be much further up.
"But I've said from the start of the season I expected the newly-promoted teams to stay up and I still believe that.
"Norwich are almost a certainty and Swansea are close to being safe and the only ones who are in any difficulty are QPR but I've always had a feeling they have enough to get out of trouble.
"They have spent well and they will fight all the way to the end."
Source: PA
Source: PA