Can a Facelift Be Tweaked Afterwards if One Side of my Face is Saggier?

It is possible to have a revision surgery to correct any concerns you've developed, but please wait about 6 months after your initial surgery.

Although it is hard to tell without seeing your pictures what you are describing is possibly due to having less volume (fat0 on one side of your face.  You should consider fat grafting as an option.

Your question is a good one. The important thing to remember during the post-operative healing process is that asymmetries inevitably occur but will typically resolve on their own after a period of six to twelve months.  Minor adjustments are sometimes necessary after this period, and you should make an appointment to see your surgeon to discuss your concerns.

It is absolutely normal and reasonable to have a touch up procedure to help you achieve everything you were looking for from your surgery.  Your timing for a revision is about right also.  Contact your surgery and schedule a visit to discuss this option.  Offices have differing policies regarding revisional surgery, but most charge a discounted surgeon's fee for this type of work but require that you bare the expense of the operating room and anesthesia.

5 months after your primary procedure, it is still possible to have slight asymmetries which could resolve spontaneously.  I would recommend waiting a full year prior to considering any type of revision work.