Earlier this year the FDA approved Bellafill, the first injectable that claims to last safely for five years. With the much more popular hyaluronic acid fillers, people have to go in every six to nine months, which can be tiresome and expensive. However, unlike those short-term fillers, Bellafill is not reversible. The injectable was previously approved for filling smile lines and acne scars, and while it has not been studied as a volumizer for cheeks, it can be used in that area, off-label. It should not be used in the lips.

Bellafill’s five-year approval is based on the world’s largest and longest dermal-filler study, completed in February 2014. It involved 1,008 patients (88.9 percent of them female) in 23 centers across the U.S. who received injections of Bellafill in their nasal-labial folds (a.k.a. smile lines). At five years, there was an 87 percent retention rate. The formula (a reformulation of a previous filler called Artefill) is comprised of collagen, polymethylmethacrylate (PMMA) microspheres, and 0.3 percent lidocaine, a pain deadener for injection comfort.

So how does it work, exactly? After injection, the body absorbs the collagen over time and the PMMA spheres remain to plump the area. First-time users need to plan ahead, however, to make sure they’re not among the small percentage of the population that is allergic to cow collagen. All new patients must take an allergy test on an arm one month in advance of injection. In the five-year study, the incidence of treatment-related adverse events was 11.7 percent—and almost three quarters of those events were mild, one quarter were moderate, and 2 percent were severe. The most common complaints were redness, swelling, pain, tenderness, lumpiness, and granulomas.

With a short-term filler such as hyaluronic acid, any regrets can be addressed with an injection of hyaluronidase, which dissolves the acid gel. But Bellafill is nonreversible, so it’s important to understand the possible side effects. A lump is a palpable filler or scar tissue that has formed and can be transitory.

In contrast, granulomas are inflamed lumps or nodules. They are treated with steroids and/or a strong chemical agent called 5-FU.

At the end of the Bellafill study, 83 percent of participants rated themselves satisfied or very satisfied—and even those who had experienced lumps were almost equally pleased. Patients in the study reported better results at five years than at one year.

There is an ongoing but steady state of augmentation as the body responds to the PMMA spheres by laying down new collagen. These results should be reassuring to patients who want a long lasting

filler.