Restylane Lyft for "deep" tear-trough filler - good or bad idea?

Thank you for your question.  It is important that you seek out care from advanced practices preferably associated with board certified plastic surgery providers for your injections.  This is essential when treating areas such as the tear trough where you want to have the local or regional with the most experience possible perform these specialty injections. Technique and experience of the injector impacts outcome particularly in these areas.  We do NOT suggest Restylane Lyft in the tear trough region as this filler is a bit too thick and cohesive.  A softer product is needed for this delicate region and injection using a blunt tip canula to ensure safety is recommended.  Refyne is a better Galderma product for this area although again is an off-label, albiet safe, application of HA fillers. All My Best ~ Dr. Bengtson

Lyft can be used in the tear trough, but it is not very popular in this location in the hands of most surgeons. The most popular filler for the tear trough continues to be Restylane. It's a decision that needs to be based on the goals and physical examination, but it would not be inappropriate to suggest lyft to some patients.
Best wishes, Dr. ALDO 

Great Question! 
Each patient is different and presents unique issues. I don't use lyft in the troughs and here's why: the eyelid skin (in the trough area) is the thinnest skin in the whole body. We know that if we place thick or "harsh" fillers in these places that it shows... big time. 
We also know that there can be several issues resulting in hollows under the eyes.. Soft tissue changes is the main issue. I don't think that placing material on the bone is the best way to treat this problem. Yes, some patients get bony resorption, but most patients have problems with the soft tissue- thus in my hands, I use a filler that is able to be placed in the soft tissue. This gives my patients an excellent outcome. 
Be careful with your face- not saying their way is wrong.. just do your homework (as you're doing!) 
hope this helps and God Bless!
Dr. Robb