For Those Curious About Fillers
When you find yourself concerned about losing skin elasticity or volume, the word "filler" tends to come up frequently. Yet many patients who come in for consultations ask, "Aren't all fillers basically the same?" To answer that directly: fillers differ considerably in mechanism, duration, and suitable treatment areas depending on the ingredient family.
In this article, Dr. Kim Gun-woo, Medical Director of Cellinique on Dosan-daero, Gangnam, shares the ingredient-by-ingredient characteristics he explains most often during actual consultations. Rather than ranking one filler as "better" than another, the goal is to help you understand how each ingredient works and when each might be considered. The specific product selection and suitability for your individual case are always decided during a prior consultation.
3-Point Summary
1. Fillers are classified by ingredient family into HA (hyaluronic acid), CaHA (calcium hydroxyapatite), PLLA (poly-L-lactic acid), and others — each with a different mechanism and duration.
2. HA fillers are frequently cited for their flexibility because they can be dissolved with hyaluronidase; CaHA and PLLA are described in the literature as working by stimulating collagen production.
3. All filler procedures carry the risk of serious complications such as vascular occlusion. The practitioner's anatomical knowledge and safety protocols play a decisive role in outcomes. Which ingredient is appropriate for you is determined through a personal consultation.
1. What Is a Filler? An Overview of Ingredient Classifications
A filler is the general term for injection procedures that add volume or adjust contours by introducing material into the skin or subcutaneous tissue. Although they are often lumped together as "just filler," the mechanism, duration, side-effect profile, and suitable areas differ substantially by ingredient family — which is why understanding the ingredient is the starting point for any treatment decision.
The major ingredient families most commonly used in clinical practice are as follows.
- HA (hyaluronic acid) — a polysaccharide family similar to a substance naturally present in the body
- CaHA (calcium hydroxyapatite) — calcium-phosphate mineral microspheres
- PLLA (poly-L-lactic acid) — a biodegradable synthetic polymer family
- PMMA (polymethylmethacrylate) — semi-permanent synthetic microspheres
Approval status may differ between Korea's MFDS and the U.S. FDA for each ingredient and specific product. The most accurate way to verify the approved indications for a particular product is to check directly with the primary source (Korea's MFDS nedrug portal or FDA accessdata) using the product name and approval number. This article provides general information organized around ingredient categories.
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Sources: Korea's MFDS (Ministry of Food and Drug Safety) · U.S. FDA
- The domestic approval status, approved indications, and scope of filler products should be verified on the MFDS Medical Device/Drug Information portal (nedrug.mfds.go.kr) using the product name and approval number.
- U.S. FDA approval ("FDA approved") must be confirmed directly in the FDA accessdata (accessdata.fda.gov) PMA/510(k) database; this article does not assert FDA approval for any individual product.
- Effects and duration vary among individuals; general information by ingredient family is provided in each section below.
2. HA Fillers (Hyaluronic Acid)
HA fillers use hyaluronic acid as their primary ingredient. Hyaluronic acid is a polysaccharide that occurs naturally in the body — in skin, joints, and elsewhere — and has been used in medicine and aesthetics for many years due to its exceptional water-retention capacity. For use as a filler, it is processed through crosslinking to control the rate of degradation.
Key Properties of HA Fillers
- Reversibility: HA fillers can be dissolved and corrected by injecting the enzyme hyaluronidase — a property consistently described in the literature that distinguishes them from other ingredient families. This property is clinically significant in emergency vascular occlusion situations.
- Duration: Results vary greatly depending on the degree of crosslinking, injection site, and individual metabolism. They are commonly described as lasting several months to approximately one year, but this varies by product, site, and individual. The same results cannot be guaranteed.
- Range of use: Used in a wide range of areas including volume restoration (cheeks, jawline), lips, tear troughs, forehead, and nose. Suitable sites are determined in consultation based on the product's viscosity (G' value) and degree of crosslinking.
- Raw material: Most clinical HA fillers are currently produced using non-animal biotechnology synthesis methods (NASHA and similar processes).
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Sources: General information based on PubMed literature · Korean Society for Aesthetic and Reconstructive Surgery (KAAPS) guideline reference
- The reversibility of HA fillers (dissolvable with hyaluronidase) is a property consistently described in academic literature.
- Duration and effects vary considerably depending on the product's degree of crosslinking, injection site, and individual metabolic rate; the same results cannot be guaranteed.
- To verify Korea's MFDS approval status for a specific HA filler product, please search by product name at nedrug.mfds.go.kr.
Key Considerations When Receiving HA Filler Treatment
HA fillers are available in various viscosities depending on the target area and goal. The spectrum ranges from soft formulations suitable for superficial layers to high-viscosity formulations used for deeper volume correction — which product is injected at which depth affects both outcomes and safety. At Cellinique, the characteristics of each area and the individual's condition are assessed during the consultation first.
3. CaHA Fillers (Calcium Hydroxyapatite)
CaHA fillers consist of calcium hydroxyapatite microspheres dispersed in a carboxymethylcellulose (CMC) gel carrier. Calcium hydroxyapatite is a mineral-family substance similar to the natural components found in bone and teeth.
Key Properties of CaHA Fillers
- Dual action: Immediately after injection, the gel carrier provides immediate volume, while the CaHA microspheres subsequently work to stimulate collagen production, as described in animal and clinical studies in the literature. However, the amount of collagen produced and the resulting effects vary among individuals.
- Duration: Often described as longer than HA fillers, typically cited as approximately 1–2 years, but variation by site and individual is significant. Results are not guaranteed.
- Non-reversibility: Unlike HA fillers, there is no dissolving enzyme, making correction difficult. This makes the design of injection site and depth even more important.
- Suitable areas: Often used for deep volume correction, lower face (jawline and cheeks), and the backs of the hands. Superficial injection carries a risk of nodule formation, so area selection requires careful consideration.
4. PLLA Fillers (Poly-L-Lactic Acid)
PLLA fillers use poly-L-lactic acid as their primary ingredient — a biodegradable synthetic polymer family. PLLA, which has been used in the medical field for a long time in applications such as surgical sutures, is manufactured into microparticles and injected into the dermis and subcutaneous layer.
Key Properties of PLLA Fillers
- Collagen stimulation as the primary goal: Rather than providing immediate volume, PLLA is often classified and described as a "biostimulator" that works by stimulating the body's own collagen production. Immediate volume effect is limited; changes appear gradually over weeks to months.
- Duration: Some literature describes durations of two years or longer, but this varies depending on individual metabolism, number of sessions, and treatment area. Results are not guaranteed.
- Non-reversibility: Like CaHA, there is no dissolution method, making correction difficult.
- Multiple sessions: The approach generally recommended involves multiple sessions; a single treatment is not typically structured to produce the final result.
- Precautions: There are reports that the dilution method and injection technique affect the rate of nodule formation, making the practitioner's technical understanding important.
5. Filler Ingredient Comparison at a Glance
The table below is a reference guide comparing the general characteristics of each ingredient family. Differences by product and individual are substantial, and this is not meant to imply that any one ingredient is superior. Which ingredient is appropriate for you is determined through a consultation.
| Category | HA (Hyaluronic Acid) | CaHA (Calcium Hydroxyapatite) | PLLA (Poly-L-Lactic Acid) |
|---|---|---|---|
| Ingredient family | Polysaccharide (hyaluronic acid) | Calcium-phosphate mineral microspheres | Biodegradable synthetic polymer |
| Primary mechanism | Immediate volume and hydration | Immediate volume + collagen stimulation | Collagen stimulation (gradual change) |
| Duration (reference) | Several months to ~1 year (varies greatly by product and site) | ~1–2 years (significant individual variation) | ~2+ years cited (significant individual variation) |
| Reversibility | Dissolvable with hyaluronidase | No dissolution method (correction difficult) | No dissolution method (correction difficult) |
| How results are experienced | Immediately noticeable after treatment | Immediate + gradual change over time | Gradual change over weeks to months |
| Primary application areas (general) | Cheeks, nose, lips, tear troughs, forehead, and more | Deep volume, lower face, backs of hands | Cheeks, forehead, overall face (broad collagen stimulation) |
| Key precautions | Vascular occlusion risk, over-correction | Non-reversibility, nodule risk with superficial injection | Non-reversibility, multiple sessions, nodule risk |
※ The duration figures above are based on published literature and clinical reports; individual results vary significantly based on skin condition, metabolism, and lifestyle. Results are not guaranteed.
6. PMMA Fillers (Polymethylmethacrylate)
PMMA consists of polymethylmethacrylate microspheres dispersed in a collagen gel or biocompatible gel carrier. The PMMA microspheres themselves do not degrade in the body, giving them a semi-permanent character.
Given their semi-permanent nature, thorough pre-treatment consultation and careful evaluation of indications are essential. Because correction is extremely difficult once injected, the options available if undesired results occur are more limited compared to other ingredient families. At Cellinique, PMMA-type fillers are discussed on an individual basis during consultation.
7. Safety Considerations Common to All Filler Ingredients
All fillers share the common characteristic of being injection procedures, regardless of ingredient. The risk that filler entering a blood vessel can cause serious complications such as tissue necrosis or vision loss applies equally to every ingredient.
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Sources: Korean Society for Aesthetic and Reconstructive Surgery (KAAPS) safety guideline reference · Common warning items in medical literature
- Vascular occlusion: If filler is injected into a blood vessel or compresses a vessel, it can lead to serious complications including skin necrosis and reduced vision or blindness. This risk applies to all injectable fillers regardless of ingredient.
- For HA fillers specifically, emergency dissolution using hyaluronidase has been reported, and this is cited as one of the clinical distinguishing features of HA fillers in vascular occlusion emergencies.
- Whether and to what extent side effects occur is directly linked to the practitioner's anatomical knowledge, injection technique, and pre-treatment safety assessment.
Information to Disclose Before Any Filler Procedure
- Pregnancy, breastfeeding, or plans to become pregnant
- Use of anticoagulants, antiplatelet agents, or immunosuppressants
- Active infection or inflammation in the target area
- History of autoimmune disease or allergies (especially to ingredients or anesthetics)
- Recent procedures on the same or adjacent area
- History of prior filler treatments, including which ingredients were used
Symptoms Requiring Attention After Treatment
- Severe redness, heat, or persistent pain at the treatment site
- Skin color changes (pallor, purple discoloration, or darkening)
- Vision changes, headache, or dizziness
- A nodule that feels firm for more than two weeks or is growing larger
If any of the above symptoms appear, please contact the treating clinic immediately or visit an emergency room.
8. Which Ingredients Are Considered for Which Areas?
The following reflects general tendencies; actual ingredient and product selection is determined in consultation based on individual condition, goals, and prior treatment history. There is no single "correct" answer for which ingredient suits which area.
| Area | Commonly Considered Ingredient Families (general tendency) | Key Considerations |
|---|---|---|
| Nose | HA family | High vascular density makes vascular occlusion risk management particularly important in this area |
| Lips | HA family (soft formulation) | Formulation selection for natural movement is important |
| Under-eye area (tear trough) | HA family (low viscosity) | Area requiring caution due to thin skin, vascular density, and Tyndall effect |
| Cheeks, zygoma, facial volume | HA, CaHA, or PLLA may all be considered | Varies depending on goal (immediate volume vs. collagen stimulation) and individual condition |
| Jawline, lower face | HA or CaHA family | An area requiring deep injection, making the practitioner's technique important |
| Forehead | HA or PLLA family | Area requiring shallow injection and vascular caution |
9. What to Consider When Choosing a Filler
When selecting a filler ingredient, the most important question is not "which ingredient is trending right now" but "which ingredient's mechanism aligns with my skin condition and goals." Here are key points to clarify during your consultation.
- Direction of desired change: Whether you want immediate volume correction or gradual change over time through collagen stimulation
- Preference for reversibility: Whether reversibility (HA dissolvability) is important to you
- Acceptable downtime: How much recovery time you can accommodate after treatment
- Prior treatment history: History of filler treatments, which ingredients were used, and when (to consider interactions between ingredients)
- Medications and health status: Anticoagulants, immunosuppressants, etc.
At Cellinique, these factors are thoroughly reviewed during the pre-treatment consultation before we advise on the ingredient, product, and injection design that best suits your individual situation.
10. Cellinique's Approach to Filler Consultations
Cellinique is an anti-aging-focused clinic located on Dosan-daero in Gangnam-gu. For procedures like filler injections, where anatomical knowledge and injection technique are directly linked to safety, Dr. Kim Gun-woo personally handles every step — from consultation and treatment planning to the procedure itself and follow-up assessment.
There are two points Dr. Kim particularly emphasizes in filler consultations. First, it is not so much what is injected (ingredient selection) but where and how much is injected (injection site, depth, and volume design) that determines both results and safety. Second, understanding each patient's vascular distribution and individual anatomy before treatment, and having a protocol in place for vascular occlusion emergencies, is a fundamental baseline requirement.
Being located on Dosan-daero also carries a practical advantage: if a patient suspects an adverse reaction after treatment, they can return quickly for reassessment. This matters because monitoring and adjustment after the procedure is an important part of filler treatment overall.
Frequently Asked Questions (FAQ)
Q1. There are so many filler types — how do I choose?
The selection involves weighing several factors: the mechanism of each ingredient family (immediate volume vs. collagen stimulation), preferred duration, importance of reversibility, treatment area, and individual health status. Rather than chasing the most popular filler, it is more important to match the ingredient to your goals and skin condition. Which ingredient is appropriate is determined during a prior consultation.
Q2. Which is better — HA filler, CaHA, or PLLA?
Rather than ranking them, it depends on your goal. If you want immediate volume correction and value reversibility (the ability to correct), HA fillers are frequently considered. If you prefer gradual change through collagen stimulation, CaHA or PLLA become the candidates. Each ingredient has its own advantages and drawbacks, and the choice varies based on goal and area.
Q3. How long do fillers last?
Duration varies considerably by ingredient family, product, injection site, and individual metabolism. HA fillers are often described as lasting several months to approximately one year; CaHA approximately 1–2 years; PLLA two or more years in some cases — but these are general reference ranges and are not guaranteed. Individual variation based on skin condition and lifestyle is significant.
Q4. Can fillers be corrected after treatment?
HA fillers can be dissolved and corrected using the enzyme hyaluronidase. CaHA, PLLA, and PMMA have no dissolution method, making correction difficult. This is why pre-treatment planning and indication evaluation become even more critical with non-reversible ingredients.
Q5. What is vascular occlusion and how serious is it?
Vascular occlusion (vascular occlusion) refers to a situation in which filler is injected into a blood vessel or externally compresses a vessel, blocking blood flow. In serious cases, this can lead to tissue necrosis in the affected area, or — if the vessels supplying the eye are affected — vision loss or blindness. It is considered the most critical safety issue in filler treatment. Areas with dense vascular distribution, such as the nose, perioral region, and glabella, require particular caution. The practitioner's anatomical knowledge, injection technique, and emergency-response capability are the key factors in reducing this risk.
Q6. Can multiple filler ingredients be combined in one session?
Whether combining ingredients is appropriate depends on the area, sequence, and timing. Overlapping different ingredients in the same area within a short period is generally not recommended. Prior treatment history and current condition must first be assessed during a consultation. When a combination is needed, it is designed with careful timing and sequencing.
Q7. What are the possible side effects of fillers?
Common side effects include temporary swelling, redness, and bruising at the treatment site. Nodules, infection, and allergic reactions are reported rarely. The most serious complication is vascular occlusion (potentially causing tissue necrosis or blindness). Whether and to what degree side effects occur depends on the practitioner's technique, individual condition, and ingredient family. If an adverse reaction is suspected, the treating clinic should be contacted immediately.
Q8. Can I just come in for a consultation without committing to treatment?
Absolutely. Because filler treatment outcomes and safety depend so heavily on ingredient selection, area planning, and volume design, we actually encourage patients to fully understand the procedure through consultation before making a decision. You are welcome to contact us at 02-6203-3434 or via KakaoTalk for a consultation alone, regardless of whether you proceed with treatment. (Consultation and treatment fees vary depending on individual condition and design and will be discussed during the consultation.)
Closing
Fillers are a medical procedure in which mechanism, duration, reversibility, and suitable treatment areas differ by ingredient. Rather than a simple ranking of "which filler is better," the key is choosing an ingredient whose mechanism aligns with your goals, skin condition, and the type of change you are seeking.
At Cellinique on Dosan-daero, Gangnam, Dr. Kim Gun-woo personally handles every aspect — from filler ingredient selection and injection design to the procedure itself and post-treatment assessment. If you are interested in fillers, we invite you to start with a consultation to talk openly about what kind of change you are looking for. General safety standards can be found on our Cellinique Treatment Safety Information page.
✅ Fact-Check Report
The primary medical information in this article was prepared with reference to the following sources and standards.
- Korea's MFDS (Ministry of Food and Drug Safety) — Domestic filler approval principles (individual product approval numbers and indications should be verified directly at nedrug.mfds.go.kr; this article does not assert specific product approval numbers)
- U.S. FDA — U.S. filler approval principles (individual product FDA approval status should be verified directly at accessdata.fda.gov; this article does not assert FDA approval for any specific product)
- Korean Society for Aesthetic and Reconstructive Surgery (KAAPS) guideline reference — Safety principles and vascular occlusion precautions
- Ingredient-category property descriptions — HA reversibility (hyaluronidase), CaHA dual action, and PLLA collagen-stimulation mechanism are described as general information consistently reported in academic literature
- Verification items: prohibited expressions (100% efficacy, guarantee, best, no side effects, specific prices) zero occurrences; no prohibited_claims; individual variation, side-effect possibility, and vascular occlusion risk disclosed; no disparagement or definitive ranking of specific competing brands; no assertion of FDA approval for specific products.
Results, maintenance, and suitability vary among individuals based on skin condition, age, and lifestyle, and identical outcomes cannot be guaranteed.
This procedure carries the possibility of side effects such as temporary erythema and edema, and contraindications may apply — these will be reviewed during your pre-treatment consultation.
Medical Disclaimer
This content is provided for general health information purposes only. Individual diagnosis and treatment must be discussed with a qualified medical professional.
Cellinique Consultation & Appointments
228 Dosan-daero, Gangnam-gu, Seoul (Yeonseung Building, 2F & B1)
Tel: 02-6203-3434
Hours: Mon–Fri 10:00–19:00 / Last Saturday of each month 10:00–16:30
