Double Board-Certified, Harvard-Trained · 141 Documented Before-and-After Cases · 4.9 Average  ·  314 Reviews

Underneath the skin, the scaffolding is changing

As the face ages, deep fat compartments shrink and shift, the underlying bone remodels and loses projection, and skin loses the collagen and elastin that once gave it a taut, supported quality. The result isn't simply "loose skin" — it's a genuine loss of the structural volume that skin used to be draped over, which is why skin alone, no matter how tight, can't fully restore a youthful contour once that support is gone.

Significant weight loss can produce a similar effect at any age, hollowing the cheeks and temples independent of the aging process. Dermal fillers work by directly replacing that lost volume beneath the skin — restoring the support structure rather than just smoothing the surface above it.

Not every filler does the same job

Each filler family is engineered with a different cross-linking density, consistency, and lifting capacity — which is why Dr. Kim selects a specific product for each treatment zone rather than defaulting to one filler for the whole face.

AreaTypical Product FamilyWhy
Cheeks & midfaceRestylane Lyft, Juvéderm Voluma, RADIESSEDenser, higher lift-capacity gels that support significant volume against gravity.
Nasolabial folds & marionette linesRestylane Defyne, Juvéderm VollureFlexible cross-linking (e.g. Restylane's XpresHAn technology) allows the gel to move naturally with facial expression.
Tear troughs (under-eye)Restylane, Juvéderm VolbellaVery soft, low-viscosity formulas suited to the thin skin of the lower eyelid.
Fine lines & superficial textureRestylane Silk, Belotero BalanceThinner gels that integrate smoothly into delicate skin without visible lumping.
Broad volume loss / collagen stimulationSculptra (poly-L-lactic acid)Works differently than HA fillers — stimulates the body's own collagen production gradually over several sessions.
HA vs. non-HA fillers. Restylane, Juvéderm, and Belotero are all hyaluronic acid (HA) fillers — reversible with an enzyme (hyaluronidase) if ever needed. RADIESSE (calcium hydroxylapatite) and Sculptra (poly-L-lactic acid) work through different mechanisms and are not reversible in the same way, which is part of why Dr. Kim reserves them for zones and patients where their specific properties are the right fit.

The same product doesn't last the same way twice

How long a filler lasts has less to do with the product alone than with where it's placed. The lips move almost constantly — talking, eating, expressing — and sit in an area with dense blood flow and thin overlying skin, all of which accelerate how quickly the body breaks the gel down. Lip filler typically lasts on the shorter end of the range, often 6–12 months.

The cheeks, by contrast, are relatively static and are usually treated with denser, structural gel placed against or near bone — a combination that consistently produces the longest-lasting results of any facial zone, often 12–24 months. Individual metabolic rate also plays a real role: patients who metabolize filler more quickly will generally see any given product resolve sooner than the published averages, regardless of where it's placed.

Why the benefit outlasts the product

Dermal filler is often described as "temporary," which is true of the gel itself — but it isn't the whole story. Published research has found that cross-linked hyaluronic acid filler placed in the skin causes the body's own fibroblasts (the cells responsible for producing collagen) to stretch and activate through a mechanical process called mechanotransduction, essentially triggering those cells to lay down new type I collagen in response to the physical support the filler provides.

In one published study, this collagen-building effect was still measurable a full year after a single injection — well after much of the filler itself would be expected to have broken down. This is part of why patients who maintain a consistent filler schedule over time often notice their skin holding its improvement increasingly well between appointments: each treatment isn't simply starting over from scratch, but building on a foundation of collagen the previous treatments helped stimulate.

A note on the research. This mechanotransduction effect — HA filler mechanically activating fibroblasts to produce new collagen via the TGF-β signaling pathway, independent of any inflammatory response — has been documented in peer-reviewed dermatology literature studying photoaged skin, with collagen changes persisting at least 52 weeks post-injection.

Two different problems, two different tools

Dermal fillers and wrinkle relaxers like Dysport or Botox are frequently confused, but they solve opposite problems. Wrinkle relaxers address dynamic lines caused by repeated muscle movement — they work on the muscle. Fillers restore lost volume and static folds — they work on the missing structure beneath the skin.

Many patients benefit from both, combined in a single visit or treatment plan — a "liquid facelift" approach that addresses movement-related lines and volume loss together for a more complete non-surgical result.

Filler injected too close to a blood vessel can, in rare cases, cause a vascular occlusion — a serious complication that can compromise skin or, in the nasal and glabellar regions, vision. This risk is directly related to injector experience and anatomical knowledge, which is why Dr. Kim, as a facial plastic surgeon who operates on this exact anatomy surgically, personally performs all filler injections. Hyaluronidase, an enzyme that dissolves HA filler, is kept on hand and can reverse an HA filler if ever medically necessary.

Dermal Filler FAQs

How do I know which filler is right for me?

The right product depends on the treatment area, the depth and type of volume loss, and your individual goals. Dr. Kim will recommend a specific product — or combination of products — during your consultation, rather than applying a single filler type to every concern.

How long do results last?

This varies by product and, just as much, by treatment area — thinner fillers in high-movement areas like the lips typically need refreshing within 6–12 months, while denser fillers placed for structural support in the cheeks can last 12–24 months. Sculptra builds gradually and can stimulate collagen production for up to two years. On top of that, the collagen-stimulating effect of filler itself tends to make each subsequent treatment hold its result a little better than the last.

What areas can be treated with fillers?

Cheeks, temples, tear troughs, nasolabial folds, marionette lines, chin, jawline, and lips are all common treatment areas. See our dedicated lip filler, cheek volume, and temple volume pages for area-specific detail.

Is there downtime?

Most patients return to normal activity immediately, with only mild, short-lived swelling or bruising at injection sites. Avoiding alcohol, strenuous exercise, and excessive makeup or facial massage for the first 24 hours helps minimize this.

In their own words

★★★★★

"Great experience — I started going to Dr. Kim because a friend referred me. He answered all my questions and made me feel very relaxed. I received Dysport and fillers. I always look so natural, never over done."

M. — RealSelf
★★★★★

"Dr. Kim is an artist when it comes to facial injectables. His technique was meticulous and overall it was a painless experience that gave me the natural, youthful results I desired."

U. — RealSelf
★★★★★

"He's a Harvard trained surgeon and an expert in his craft, but he is quiet humble and down to earth... When you go to him for cosmetics, please trust his vision."

D.M. — Google
4.9 average rating  ·  314 reviews
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