The Netherlands international left Dutch club Twente, but has struggled to find his best form in the Bundesliga so far this campaign.
"Things are not yet going as I was hoping them to go," the 22-year-old told Goal.com.
"All I can do is keep on working hard and give my all in every game. I definitely do not regret joining Gladbach.
"It's amazing to play in the Bundesliga every week. I can learn a lot here."
De Jong has scored just one goal in the Bundesliga so far.