Gwyneth Paltrow has experienced "waves of grief and sadness" since her children left home.

The 52-year-old actress has daughter Apple, 20, and son Moses, 18, with her ex-husband Chris Martin, and Gwyneth has revealed that she's struggled to adjust to her children leaving home to attend college.

During a Q and A with her fans on Instagram, Gwyneth was asked: "How's life as a free bird?"

In response, the Oscar-winning star replied: "Thank you for asking. It's very different. I have waves of grief and sadness."

On the other hand, Gwyneth acknowledged that there are some positives to her kids leaving home.

The Hollywood star said: "I am kind of getting back in touch with this part of myself that I haven't felt like since I was in my 20s before I had kids. Like, a little more space and imagination, maybe. A little more inner space for what I might want to do that day, stuff like that.

"So, it's evolving. It's interesting."

Earlier this year, Gwyneth admitted that she felt anxious about her kids going to college.

She said at the Goop Health Summit: "It’s kind of giving me a nervous breakdown.

"If I’m honest, I started being like, ‘Oh, my God, and I need to quit my job and I need to sell my house and I need to move.’ It’s sort of putting things into turmoil."

Gwyneth has enjoyed significant success with her Goop brand in recent years - but the actress always made her kids her number one priority.

Gwyneth shared: "My identity has been being a mother.

"Apple’s going to be 20 in May. So I’ve oriented my whole life around them and their schedules and when school starts.

"You start to let go in increments when they’re driving themselves around or doing certain things. It is a slower process.

"I feel really lucky because I have a close group of mom friends, and we all raised our kids alongside one another. So we’re kind of in it together."