Fraxel Laser and fat injections can be done together, do fat transfer first
I do treat patients with fat grafting and fractional laser resurfacing using Starlux2940 at the same time.
I typically do this procedure on the eyelid as part of an arcus marginalis release and fat grafting to correct dark circles under the eye.
The fat will be injected deep into the lip beneath the skin. The Fraxel will be affecting the skin surface down to 300-500 microns and will not go below the skin surface, where the fat will be placed.
I would do the fat transefer first, because once the Fraxel has been done, I would not want to then pass a needle through the resurfaced skin.
Better to separate elective procedures
I am not aware of any reported cases of complications from doing both the same day, but it is always advisable when doing elective cosmetic procedures not to take unnecessary risk. I would feel more comfortable to perform them independently.
Depends on which Fraxel treatment
If you are contemplating full face fat transfer and Fraxel re:store treatment that would be okay at the same time. I would not recommend having full face fat transfer and Fraxel re:pair at the same time due to the post treatment wound care and frequent washes and skin manipulation. Also the risk of infection would be increased.
I would recommend having the Fraxel re:pair first, followed by fat transfer after at least two months, preferably 4 to 6 months later.
Good luck and be well.