The National Enquirer is reporting that Brad Pitt has undergone filler injections as a way to look younger. According to Celebitchy :
The 46-year-old actor has been getting injections of the wrinkle filler Radiesse to make his face look younger and smoother, the Enquirer has learned. And it appears to be having the desired effect. Not only does Brad’s face look brighter and more radiant, Angelina has given her seal of approval. “Brad hasn’t looked this good in years - and Angelina is definitely pleased about his makeover…” For months, the actor hid behind a scraggly beard “because he was so self-conscious about how he was aging.”
I haven't seen photos of him, but a little Radiesse can definitely take off some years. I'd probably recommend a little Sculptra to fill in some of the gaunt areas of his face.