At 41, Jennifer Aniston's age is starting to catch up with her.
When the actress recently watched the final cuts from her upcoming romantic comedy The Switch (out Aug. 20), "she thought she looked rough -- especially in the daytime scenes," a movie insider tells the new issue of Us Weekly, on stands now.
PHOTOS: See what stars look like without airbrushing
"She wanted them retouched further, but the studio had already spent its postproduction budget," continues the source. "The studio discussed making her foot the bill for any enhancements."
Though a rep for the star tells Us that "all films go through print adjustments, and this is no different from the rest,” the insider adds that Aniston was just as self-conscious during filming, often pulling her hair down to cover any facial lines.
PHOTOS: See how Jen's bikini bod has changed over the years
Snipes the source, "She's starting to show her age."
Making matters worse: The actress -- who once declared she'd be "devastated" if coffee, dairy or wine were cut from her diet -- is currently filming Just Go With It alongside 23-year-old model Brooklyn Decker, who graced the cover of Sports Illustrated swimsuit issue earlier this year.
PHOTOS: Jen and Brooklyn filming
Aniston "is jealous" of Decker's hot bikini bod, adds a source.
For more details on Aniston's grueling seven-day-a-week exercise regimen, her "obsession" with staying young and her deprivation diet (that includes baby food, despite her denials), pick up the new issue of Us Weekly, on stands now.