Are there side effects to having Juvederm for deep wrinkles between the brows?

Dear conservative; I like your name and encourage you to follow that approach. Yours is a very important question.
Juvederm between the eyes has risk associated with skin necrosis, blindness and granuloma. 
Skin necrosis results from a blood vessel being blocked and the skin losing its blood supply, potentially dying and subsequently forming an open wound.
Blindness occurs when product travels upstream in the blood vessel between your eyes to where it meets the blood vessel that supplies the eye. It then travels downstream to the eye, cutting off it's critical blood supply. There have been over 100 cases of blindness worldwide associated with filler, the large majority being from injections in this area between the eyes. In our clinic we identify this risk in our consent forms and have patients sign with a witness. Of course, 100 patients is a small number considering how many injections have been performed worldwide, but the severity of this complication deserves patient awareness and complete understanding. 
Granuloma occurs when your body reacts to the product and forms a firm capsule around it. Granulomas will go away on their own; they are best left alone unless they are cosmetically apparent. If so, they can be treated and dissolved.
Expert injectors know their anatomy, and will be aware of the more risky areas like this one. They draw back on the needle before injecting injecting small amounts, with gentle pressure at the right depth. They watch carefully after injecting for any subtle signs of problems and have an enzyme on hand that can immediately dissolve the product. 
I recommend starting with Botox. This will relax the muscles that are creating the lines. The Botox will quickly provide a nice lift for a more rested, relaxed appearance. I ask our clients to be patient with the lines and allow them to recover naturally over time. 
I also recommend an anti-aging skin care program to help build thicker, more elastic skin. Healthy skin looks amazing and is less likely to form the creases that cause you to look angry. Laser resurfacing of healthy skin will provide safe, fabulous results by improving the quality of your skin.  
Good luck. You can never go wrong with your face treatments by being conservative!

Thank you for your question about juvederm side effects.
First and foremost, fillers in the brow/forehead area must be done by a very experienced injector.  There are risks associated with injecting fillers in any area, but the forehead has a large risk of vascular compromise.  As with any HA filler injections, you can expect some short term side effects after Juvederm injections.  The most common are bruising at the site of the injection and mild swelling over the areas treated.  Hyaluronic Acid Fillers, including Restylane Defyne are "hydrophilic" and attract and hold on to water, causing swelling.  This is typically mild and only lasts for a few days.  Your provider should also counsel you on post injection care.  This includes, but is not limited to, avoiding exercise for 24 hours, avoidance of aspirin/ibuprofen/fish oils to avoid bruising, avoiding heat or sun exposure for 24 hours, avoid waxing or laser treatments to the area for 24 hours, and avoiding massage of the injection site. 
  To be sure, see two or more experienced, licensed and board-certified providers in your area for a complete evaluation to make sure you are a good candidate and that it is safe for you to have treatment. I hope this helps.

Hi, great question. If you are looking to improve the area between your brows, I would suggest trying botox first or using it in addition to fillers. These lines in between the brows develop because of the strong muscles in this area, fillers can help the wrinkles but they will quickly reform with regular facial expressions. If you maintain with botox through the year every 3-4 month you can help to reverse wrinkles and prevent them from forming.- Dr. P