Filler Types Compared: HA, Radiesse, Sculptra

Why There Is More Than One Type of Filler

The word "filler" is in fact an umbrella term for a broad category of injectable materials. The differences between them are meaningful — not only in the duration of the result, but in mechanism of action, reversibility, and the areas in which they are appropriate.

The three main types in clinical use today:

• Hyaluronic acid (HA) — the most common. Direct, immediate fill. Reversible.
• Calcium hydroxylapatite (CaHA) — Radiesse — fill + collagen stimulation. Partially reversible.
• Poly-L-lactic acid (PLLA) — Sculptra — collagen stimulation only. Not reversible.

Hyaluronic Acid (HA) — The Foundation

Hyaluronic acid is a molecule that occurs naturally in the body — in skin, joints, eyes. In fillers, it undergoes crosslinking — a chemical process that converts it from a liquid that is absorbed within hours into a gel that lasts for months.

How It Works

HA acts as a "molecular sponge" — each molecule attracts up to 1,000 times its weight in water. When injected into tissue, it creates immediate volume and plumps the skin. The degree of crosslinking determines firmness and duration — higher crosslinking = a firmer filler that lasts longer.

Well-Known Products

• Restylane (Galderma) — a full family with products for every area. NASHA and OBT technology. Known for a natural feel.
• Juvederm (Allergan) — a parallel family using Vycross technology. Tends to be softer and to integrate more into tissue.
• Belotero (Merz) — specializes in tissue integration. Suited to delicate areas such as fine lines and around the eyes.

The Major Advantage: Reversibility

HA can be fully dissolved with hyaluronidase — an enzyme that breaks it down within hours. That means if there is a complication (vascular occlusion), an undesired result, or the patient is simply unhappy — it can be reversed. This is a significant advantage, especially for a first treatment.

Radiesse — CaHA: Fill + Stimulation

Radiesse is composed of calcium hydroxylapatite (CaHA) microspheres suspended in a carrier gel. The mechanism of action is twofold:

• Immediate fill — the carrier gel creates volume at the moment of injection, similar to HA.
• Gradual collagen stimulation — the microspheres function as a "scaffold" around which the body builds new collagen. The gel is absorbed over months, but the new collagen remains.

Radiesse is firmer than most HA products — it suits areas that require structural support: the jawline, chin, marionette lines, hands. Less suited to delicate areas such as lips or under the eyes.

Partial Reversal

There is no enzyme that breaks down CaHA immediately the way hyaluronidase dissolves HA. Studies show that sodium thiosulfate injection can partially break down the material, but it is not as precise as dissolving HA. In practice, if there is a problem — you need to wait for natural absorption (12–18 months) or turn to a surgical solution. This is an important consideration in the decision.

Diluted Use (Hyperdilute Radiesse)

An important trend in recent years: diluting Radiesse with saline and lidocaine to create a thin solution injected over a broad surface. The goal is not to fill volume but to produce widespread collagen stimulation — to improve skin texture on the neck, décolletage and hands. The result is gradual and sustained.

Sculptra — PLLA: Pure Stimulation

Sculptra is not a filler in the traditional sense — it does not fill volume. Instead, it contains poly-L-lactic acid (PLLA) that stimulates the body to produce new collagen over time.

Mechanism of Action

PLLA particles create a controlled inflammatory response (foreign body response) — the body identifies them as "foreign bodies" and encapsulates them in collagen. The particles are absorbed gradually (over months), but the collagen formed around them remains. The result: gradual thickening of the tissue that looks like "restoring natural volume."

A Different Treatment Protocol

• The result is not immediate — 2–3 treatments are needed, 4–6 weeks apart
• The full result is visible only 3–6 months after the last treatment
• Duration: 2–3 years — significantly longer than HA
• Requires home massage ("5-5-5" — five times a day, five minutes each time, for five days) to prevent granulomas

The Limitation: Not Reversible

There is no way to break down collagen the body has produced. If the result is excessive or asymmetric, you have to wait — sometimes years. For this reason Sculptra demands a particularly conservative approach and experience in volume assessment.

Comparison Table

How to Choose the Right Type

The choice between filler types is not a question of "which is better" — but "which suits the specific situation." Here are the considerations:

• First treatment? — almost always HA. The advantage of reversibility is critical when you don't yet know how the body will respond and what the expectations are.
• Delicate area (lips, under the eyes)? — HA only. The other materials are too firm, can create lumps, and cannot be dissolved.
• Structural support (jaw, chin)? — firm HA or Radiesse. Both are appropriate; Radiesse adds the effect of collagen stimulation.
• Widespread volume loss (sunken cheeks, temples)? — Sculptra is worth considering, especially if the patient prefers a gradual result that looks natural and lasts for years.
• Improving skin texture without volume? — Hyperdilute Radiesse or PN — not classic filler.

Frequently Asked Questions