How soon after a facelift would you recommend microcurrent if at all?

Microcurrent therapy is not a well established nor scientifically proven therapy.  All plastic surgeons want the best results for their patients, so if microcurrent therapy really worked to maintain results, all plastic surgeons would use it or recommend it.  I know of no plastic surgeons who use it or recommend it.  However, should you decide to use microcurrent therapy, 3 months is adequate time for healing  and no harm should occur. 

Microcurrent should be very safe to do 3 months after a Facelift.  Whether or not it will be effective is another story

The benefits of microcurrent therapy are difficult to quantify and therefore it is difficult to provide you with any definitive recommendations. I would certainly consult with your surgeon first. and definitely avoid this for a minimum of 3 weeks. You must remember that while muscle bulk may provide some rejuvenative or volume correction, the repeated use of a muscle may result in secondary animation lines or wrinkles. It is for this reason that we use botulinum toxin.