An “unrecognizable” Gwen Stefani just returned to The Voice — and it’s not just her new hairstyle that makes her look so different.

Plastic surgeons, who spoke to RadarOnline.com, speculate she might have blown almost half a million bucks on a series of brutal nips and tucks.

The No Doubt singer, 55, has traded her signature slick ponytail for long wavy tresses and full bangs – but her face also clearly has fewer wrinkles and less sagging.

Source: MEGAStefani has traded her signature slick ponytail for long wavy tresses and full bangs – but her face also clearly has fewer wrinkles and less sagging.

“The new hairstyle with bangs makes her look totally different,” Dr. Brian J. Reagan of CosmetiCare in Newport Beach, Calif, told RadarOnline.com.

“But she could have had Botox and filler, which would account for the smoother features and plumper lip.”

Plastic surgeon Dr. Charles Runels, the creator of the Vampire Facial and Vampire Facelift, said: “It appears she’s had her eyes opened a few millimeters with [Botox], and her mouth has been augmented in width and has a different shape.

“The overall effect looks younger and more sassy.”

Dr. Gary Linkov, a New York plastic surgeon who discusses celeb nips and tucks on his YouTube channel, goes even further, suggesting the “Hollaback Girl” singer may have spent as much as $428,000 on procedures over the years, including Botox, veneers for her teeth, a brow lift and two revision brow lifts, a facelift, cheek, undereye and lip filler, and an eyebrow hair transplant.

Just her Botox bill for the past 18 years could top 100 grand, Linkov said.

Dr. Corey Maas, a plastic surgeon in San Francisco, said he thinks Stefani may have had a lower facelift, noting the absence of any loose skin on her lower jaw.

Source: MEGAAn expert thinks Stefani may have had a lower facelift, noting the absence of any loose skin on her lower jaw.

“A lower facelift … does a really nice job of tightening the jawline and chin, and hers are nearly perfect,” Maas said.