Will .5ml syringe of Juvederm be enough to fill sunken tear troughs? 23 years old. (photos)

This will create very subtle improvement. I recommend getting a consultation with a cosmetic dermatologist to go over your desired results. Hope this helps.

Good Morning and thank you for your question. Typically for under eye restoration treatments I start with 1ml (0.5ml per eye) in order to achieve a desired result.  While 0.5ml is conservative to treat both under eyes you can always start with that amount and gradually inject more over time.  The best option would be to consult with an expert injector.  The great thing about injectable fillers is that they are very customized and can be tailored specially for your needs. Best of luck to you.

The amount of filler you are considering is conservative.  You may notice enough improvement with that amount.  The wonderful thing about fillers is that you can go slowly.  If you find you need more product you can always return for a touch up.