Slimmer Nose with More Height Through Fillers?

Unfortunately, generally fillers do not do a very good job reshaping the tip.  Fillers are best used to fill depressions and do limited adjustments to the bridge and profile.

Every technique has its value. And the improvement varies between areas. With tissue fillers, the nasal bridge is well treated, so is small areas of asymmetry and irregularity. However the nasal tip isn't at the top of the list. There can be improvement, but by the very nature of the product; its a soft gel, the degree of definition is limited. Plus its an area that hurts more than the bridge. So more pain, less gain. My advice is you're better of with a surgical rhinoplasty. But please choose your surgeon with care. You don't want to find you're needing injections after wards for surgical irregularities.

Great question.
Unfortunately, In my hands, surgical rhinoplasty is the treatment of choice to get narrowing and definition of a wide, flat, African American nose. Even surgery is a bit unpredictable since some noses have very thick skin, and weak soft cartilage.
You should go for a consultation with a board certified facial plastic surgeon with experience, and lots of photos of noses that resemble yours.
I hope this helps, and best regards.

The most pleasing appearance to the nose is achieved with good balance and proportion to the elements of the nose in relation to the face. In one patient a nose that is wide when viewed with respect to the face may be balanced and appear very pleasing. In another person with a different face an nose that is thinner or smaller may appear "wide". An expert in rhinoplasty can evaluate your face and determine whether or not a nonsurgical option will achieve your goals.

Fillers are great to address specific nasal shape concerns. They can in fact create the appearance of a sharper tip and a smoother bridge and less of a hump. Noses that start out wide and flat will have an improvement in the bridge with fillers. The other areas are tougher and you will likely get a modest improvement. If you are really looking for something to dramatically slim your nose and refine the tip, then you are a better candidate for surgery. Having said that, it is true that thicker skin on the nose makes it harder for the surgical result underneath to be visible on the outside, but it has a better chance of addressing all your concerns. Good luck.