Jennifer Aniston may have looked immaculate in her tuxedo-style Christian Dior top as she made her way down the red carpet, but her back told a different stoy.

While attending the premier of Lifetime's Call Me Crazy, which the Friends star helped produce, Aniston revealed some interesting marks on her back. According to US Weekly, the marks are the tell tale sign of "cupping."

The Eastern medical method, which involves suctioning glass cups to the skin using either heat or suction, is said to help stimulate circulation, although doctors debate the actual value of the procedure, reports the Huffington Post.

Aniston appears to have attempted to cover up the marks with makeup, a choice that failed to work on her tanned skin. The Daily Mail reports that the actress has been using the technique for quite some time - six years in fact.   

According to E!, Anniston is not the first celeb to go in for cupping. Gwyneth Paltrow reportedly gave the method a seal of approval while talking it up on The Oprah Winfrey Show.

Call Me Crazy deals with the perception of mental health and is produced by Aniston with the same group of executive producers who handled last years Five, A film which also aired on Lifetime and focused on breast cancer.

Meanwhile, tabloids are reporting that the actress is pregnant  and "expecting a baby with her soon-to-be-husband" Justin Theroux's child.

An insider told Star magazine: "She actually started having fertility treatments six months into her relationship with Justin!"

The source continued: "Almost two years after beginning the in-vitro process, Jen and Justin received the happy news they'd be waiting for."