How long should I wait between facial fat transfer & microneedling?

I agree , 3 weeks is plenty of time for microneedling after facial fat transfer. You want to wait enough time for the transferred fat to settle and do not want to manipulate it too much initially as it’s delicate and takes time to get incorporated into its new location.
3 weeks is a good amount of time to wait. We routinely perform microneedling with RF after facial fat transfer. So this is our protocol as well.

The success of grafting tissue requires minimizing movement and pressure during the early recovery.
Different plastic surgeons have different views on how long the process of re-establishing a blood supply and having this be secure for grafted tissue.
Three weeks is probably considered a little early for something as physical as micro needling.
Do you need to ask your surgeon what their recommendations are but I would guess most surgeons would want you to wait at least three months.
In the end whether it makes a difference or not most plastic surgeons want to patients to be very protective after fat grafting. The grafted tissue is very sensitive to not surviving and we want to do everything we can to maximize graft take.
I saw your previous posts about facelift and brow lift.
The choice of ending the incision horizontally towards your crows feet is not a good option. The incision should’ve followed your hairline up as high as it needed to not develop a dog ear. It’s really important to carefully fat plastic surgeons before considering any procedure. I recommend all patients do that by having multiple in person consultations. During each consultation ask each provider to open up your portfolio and show you their entire collection of before and after pictures.
Look very carefully at all before and after pictures and always ask them to show you pictures of patients who had similar characteristics to your own in the before pictures.
Specifically asked providers to show you examples of excellent outcomes, average outcomes and outcomes that didn’t turn out as well as they had hoped for it.
Being shown on the pre-selected pictures representing the best results of a providers career is insufficient to get a clear understanding of what average results will look like or what your results will most likely look like.
For reference a highly experienced surgeon should have no difficulty showing you at least 50 sets of before and after pictures of commonly performed procedures.
Patients need to be a bit insistent on seeing a high number of pictures including pictures not included in the show until photo albums most providers use to sell their procedures.
Recognize that you’re the person paying for the service and you are hiring the surgeon.
Do you have total right to see clear documentation of previous work including various outcomes.
Importance of finding the right provider cannot be overstated.
Best,
Mats Hagstrom MD