Dermal fillers are soft gels placed under the skin with a fine needle or a blunt cannula to restore volume, soften a fold, or shape a feature such as the lips or the cheeks. Most fillers in use today are hyaluronic acid fillers: hyaluronic acid is a sugar your body already carries in its skin and cartilage, and in a filler it is processed into a gel that holds its shape for months and is then broken down and absorbed. At Savage Serenity MedSpa in Fresno, the fillers we use are RHA and Evolysse, and both are hyaluronic acid.
Dermal fillers at a glance
What it is: a gel implant placed beneath the skin, firmer or softer depending on the job it has to do.
What it is made of: hyaluronic acid, in every filler we use. Other fillers are made from calcium hydroxylapatite or poly-L-lactic acid, and one filler that the body does not absorb is made from PMMA beads.
What it does: adds volume where the face has lost it, supports and softens folds, and shapes the lips, cheeks, and chin.
How quickly it works: the change is visible before you leave; the settled result shows as swelling goes down, usually within two weeks.
How long it lasts: months, and it varies by product, area, and person; in the RHA studies most people still had improvement in their smile lines more than a year after treatment.
Can it be undone: yes. Hyaluronic acid filler can be dissolved with hyaluronidase, an enzyme we keep on hand.
Studied in: adults 22 and older.
Who performs it here: our nurse injectors, led and trained by Angela Hash, BSN, RN, with Dr. Luis Lee as the practice’s medical director and supervising physician.
What a dermal filler is
A dermal filler is an injectable gel that adds volume beneath the skin. Regulators treat it as a medical device implant, because the gel stays in the tissue after the needle comes out, and each product is reviewed for the specific areas it is meant to treat. Soft tissue filler, facial filler, lip filler, and wrinkle filler are names for the same thing.
Fillers do three jobs. They replace volume that the face loses as fat pads thin and bone changes with age, which is why cheeks flatten and temples hollow. They support a fold from underneath, so a smile line that has deepened into a crease becomes shallower. And they shape a feature, adding definition to a lip border or projection to a chin. What a filler does not do is relax a muscle; that is the work of a neuromodulator, and the two are often used together.
Because the gel is absorbed over time, the effect of nearly every filler is temporary, and treatment is repeated to maintain it. That is also the reason a hyaluronic acid filler can be adjusted or removed early if you change your mind. To see how we use filler across the face, start with our page on dermal fillers in Fresno.
What hyaluronic acid is, and why fillers are made from it
Hyaluronic acid is a sugar, a polysaccharide, that is present in your own tissues, including skin and cartilage. It holds water, which is part of what keeps skin hydrated and flexible. In gel form it combines with water and swells, and that swelling is what produces the smoothing and filling effect under the skin.
The hyaluronic acid in a filler is not taken from a person. The RHA fillers, for example, are made from hyaluronic acid produced by bacterial fermentation, then cross linked, meaning the long sugar chains are bonded to one another so the gel holds together under the skin instead of dispersing. RHA 2, RHA 3, and RHA 4 contain the same amount of hyaluronic acid, 23 milligrams per gram, and differ in how the gel is built, which is why one is placed in the mid dermis for lines and another deeper for folds that need more support.
Each gel also carries a small amount of lidocaine, a local anesthetic, to reduce pain during the injection. Hyaluronic acid is biodegradable, so your body breaks the gel down gradually. That is the trade off at the heart of this material: results last months, not years, and in return the gel can be dissolved on purpose with hyaluronidase, the enzyme that breaks hyaluronic acid apart. Our article on dissolving filler explains when that is done and what it involves.
How a filler works once it is placed
A filler works by occupying space. Your injector places the gel at a depth chosen for the product and the area: RHA 2 and RHA 3 in the mid to deep dermis for lines and folds, RHA 4 from the deep dermis to the tissue just beneath it for folds that need more support, and, for the cheeks, RHA 4 in the deeper layers close to the bone where it can lift. Once placed, the gel takes up volume, draws in water, and gives the skin above it something to rest on.
What you see is the result of where the gel sits and how much is placed, not the gel alone. A small amount placed deep on the cheekbone changes the light across the whole midface; the same amount placed in a smile line only softens that line. This is why Angela plans filler as part of the whole face. In her words: “I look at the face as a whole and create a treatment plan that restores balance, supports the way you’re naturally aging, and still keeps you looking like you.”
Over the first two weeks the swelling settles and the result you will live with becomes visible; over the following months the body breaks the hyaluronic acid down and the volume gradually recedes.
The hyaluronic acid fillers we use
We carry two lines, RHA and Evolysse, and both are hyaluronic acid.
The RHA fillers, made by Teoxane, are FDA approved for adults 22 and older: RHA 2, RHA 3, and RHA 4 for moderate to severe smile lines and other facial folds that show with expression, RHA 4 for the cheeks and midface, RHA 3 for the lips, and RHA Redensity for the fine lines around the mouth. We carry RHA 2, RHA 3, RHA 4, and RHA Redensity.
Evolysse is a newer hyaluronic acid line from Evolus. Evolysse fillers are FDA approved for moderate to severe smile lines and other facial folds in adults 22 and older, and we carry Evolysse Smooth.
Both lines were studied on the same kind of fold, the smile line that runs from the nose to the corner of the mouth, which is the standard test for a filler. Your injector chooses between them, and among the RHA gels, by the area, the depth, and the look you want, and will tell you which product is going where before anything is opened.
Where filler is placed, and where it is not
Filler is matched to the area. The areas these products were designed and studied for are the smile lines and other folds, the cheeks and midface, the lips, and the fine lines around the mouth. Each has its own anatomy and its own risks, which is why each product is reviewed area by area and not as one general purpose gel.
Our injectors also treat the chin, the jawline, the temples, and the area under the eyes with filler. Each of those areas is planned from your anatomy at your consultation, and our Dermal Fillers page describes what each is aimed at. For the lips, product choice follows the look you want, and lip work has its own page: lip filler in Fresno.
Fillers are made and studied for the face and the backs of the hands, not for the body. The consumer rules we cite at the foot of this page say plainly not to get any type of filler or liquid silicone injected for body contouring.
What to expect: results and how long they last
The change from filler is visible right away. Swelling comes with it, so the settled result shows over the first one to two weeks as the tissue calms. In the RHA studies, treatment site reactions generally resolved within 14 days; in the Evolysse Smooth study, most side effects were mild and went away on their own within a week.
How long the result lasts depends on the product, the area, how much was placed, and you. The honest figures are the study figures. In the RHA studies of smile lines and folds, about 81 percent of people treated with RHA 2, 79 percent treated with RHA 3, and 89 percent treated with RHA 4 still had a meaningful improvement 64 weeks after their first treatment. In the RHA 4 cheek study, more than 75 percent of people rated their cheeks improved or very much improved from week 8 through week 52. In the Evolysse Smooth study, 65 percent of people still had at least a one grade improvement 12 months after treatment.
You will also see a general figure of about six to twelve months for hyaluronic acid fillers as a group. Both are true: the general figure describes the material, the study figures describe these products in these areas, and your own result will depend on where the gel was placed and how your body breaks it down. When the volume recedes, treatment is repeated to maintain it, and your injector will tell you what interval to expect for the product and area you had treated.
Risks, side effects, and when to call
Every filler carries risks, and the common ones are the ones you can see. Expect some swelling, redness, tenderness or pain, bruising, firmness, and lumps or bumps at the injection site, most of them mild. In the RHA studies these generally resolved within 14 days. In the Evolysse Smooth study, about 64 percent of people had tenderness, 56 percent swelling, 53 percent lumps, and 52 percent bruising, and most of these went away on their own within a week.
The serious risk is the gel going into a blood vessel. The FDA’s patient information for these fillers puts it this way: “One of the risks with using this product is the unintentional injection into a blood vessel. The chances of this happening are very small, but if it does happen, the complications can be serious, and may be permanent. These complications, which have been reported for facial injections, can include vision abnormalities, blindness, stroke, temporary scabs, or permanent scarring of the skin.”
Rarer problems reported with fillers include infection, lumps or nodules that may need treatment, movement of the gel from where it was placed, and swelling that appears weeks or months later, sometimes after an illness, a vaccination, or dental work. The higher risk spots for the most serious outcomes are between the brows, the nose, the forehead, the upper part of the smile line, and the inner corner under the eye, which is one reason product and placement are chosen so carefully.
Call us right away, or seek emergency care, if you have any of these after treatment: changes in your vision; signs of a stroke, including sudden difficulty speaking, numbness or weakness in your face, arms, or legs, difficulty walking, face drooping, severe headache, dizziness, or confusion; a white, gray, or blue appearance of the skin near the injection site; or unusual pain during or shortly after treatment. Also call if you have significant pain away from the injection site, redness or visible swelling that lasts more than a few days, or any side effect that appears weeks or months after treatment. We keep hyaluronidase on hand for exactly this reason.
Before treatment, tell us if you have severe allergies or a history of anaphylaxis, an allergy to gram positive bacterial proteins or to lidocaine, a bleeding disorder, or a cold sore, pimple, rash, or other active skin problem at the treatment area. Tell us as well if you are pregnant or breastfeeding, since these fillers have not been studied in pregnancy or breastfeeding, and if you have dental work, a procedure, or a vaccination planned within two weeks on either side of your appointment. Our article on who should not have dermal filler goes further.
Serious side effects are more likely when the person injecting the filler does not have adequate medical training and experience. That sentence is the American Academy of Dermatology’s, and it is the reason the question of who is injecting you, and under whose supervision, matters more than the brand.
What a filler appointment looks like here
A filler appointment at Savage Serenity begins with a consultation. Your injector looks at your face as a whole, listens to what bothers you, and tells you what filler can and cannot do about it. The plan names the product, the area, and roughly how much, and you hear it before anything is opened.
The injection itself takes minutes per area. The gel contains lidocaine, so the area numbs as the product goes in, and your injector works with a fine needle or a blunt cannula depending on the area and the depth.
Aftercare is written and goes home with you. For the first 24 hours, keep the treated area away from extreme heat or cold, such as a sauna or an ice pack held on the skin; wait until the next day to exercise; stay out of the sun and away from tanning beds; and avoid touching the treated area for three days unless your injector asks you to massage it. Keep dental work and other procedures at least two weeks away on either side. If your injector’s written instructions differ from these, follow your injector.
Angela leads the practice and trains the injector team in her facial balancing approach. Dr. Luis Lee is the practice’s medical director and supervising physician.
Who filler is not for
Filler is not for everyone, and a good consultation says so. It will not lift skin that has lost its elasticity the way surgery can, and it will not stop a muscle from moving. It is not placed in an area with an active skin infection until that clears. The fillers we use were studied in adults 22 and older; your injector will talk through age with you at your consultation. And if what you want is to look like someone else, Angela will say so plainly, because her goal is never to change someone’s face.
Frequently asked questions about dermal fillers
Is a dermal filler the same as Botox?
No. A dermal filler adds volume beneath the skin; Botox and the other neuromodulators relax the muscle that creases the skin above it. Filler treats folds, hollows, and shape, and a neuromodulator treats lines made by expression. Many people use both, and your injector will tell you which one, or which combination, fits what you are describing.
How long does a dermal filler last?
It depends on the product, the area, and you. In the RHA studies, between about 79 and 89 percent of people still had improvement in their smile lines 64 weeks after their first treatment, and in the Evolysse Smooth study about two thirds still had improvement at 12 months. Hyaluronic acid fillers as a group are often described as lasting about six to twelve months. Your injector will tell you what to expect for your area.
Does getting filler hurt?
Most people feel pressure and a pinch. The gel contains lidocaine, so the area numbs as the product goes in. Tenderness afterward is common and usually mild, and it generally settles within two weeks.
Can dermal filler be dissolved?
Yes, if it is hyaluronic acid. Hyaluronidase is an enzyme that breaks hyaluronic acid apart; it is the treatment of choice when filler blocks a blood vessel, and it is also how unwanted or migrated filler is removed. We keep it on hand. Fillers made of other materials cannot be dissolved this way. Our article on dissolving filler covers the process.
What is the difference between a hyaluronic acid filler and Sculptra?
A hyaluronic acid filler adds volume the day it is placed. Sculptra is made of poly-L-lactic acid and works differently: it is used for smile lines and other facial folds and for fine lines in the cheeks, and the body may produce new collagen in response to it over a series of sessions. Our comparison of hyaluronic acid fillers and Sculptra walks through when each fits.
How much does dermal filler cost?
Filler is priced per syringe, and the number of syringes depends on the area and the plan. Ask us what the price includes. Your consultation sets the plan and the cost before anything is scheduled.
Can I get filler if I am under 22?
The fillers we use were studied in adults 22 and older; your injector will talk through age with you at your consultation.
Book a filler consultation in Fresno
If you are weighing filler for the first time, or you have had it elsewhere and want a second opinion on your face as a whole, request a consultation at Savage Serenity MedSpa in Fresno. You will leave knowing what filler can do for you, which product would go where, and what it would cost.
Keep reading
- Dermal Fillers in Fresno: products, areas, and what to expect
- Hyaluronic Acid Fillers vs Sculptra: The Key Difference
- Dissolving filler: what the process involves
- Lip Filler in Fresno
- Angela Hash, BSN, RN
Sources
- U.S. Food and Drug Administration. Dermal Fillers (Soft Tissue Fillers). https://www.fda.gov/medical-devices/aesthetic-cosmetic-devices/dermal-fillers-soft-tissue-fillers. Content current as of 07/06/2023.
- U.S. Food and Drug Administration. FDA-Approved Dermal Fillers. https://www.fda.gov/medical-devices/aesthetic-cosmetic-devices/fda-approved-dermal-fillers. Content current as of 11/09/2020.
- U.S. Food and Drug Administration. Dermal Filler Do’s and Don’ts for Wrinkles, Lips and More. https://www.fda.gov/consumers/consumer-updates/dermal-filler-dos-and-donts-wrinkles-lips-and-more. 07/07/2023.
- U.S. Food and Drug Administration. Instructions for Use, RHA 2, RHA 3, and RHA 4 (P170002). https://www.accessdata.fda.gov/cdrh_docs/pdf17/P170002C.pdf. Approved 10/19/2017.
- U.S. Food and Drug Administration. RHA 3 Directions for Use, lip augmentation (P170002/S030). https://www.accessdata.fda.gov/cdrh_docs/pdf17/P170002S030C.pdf. Approved 10/27/2023.
- U.S. Food and Drug Administration. RHA Dynamic Volume and RHA 4 Instructions for Use, cheeks and midface (P170002/S048). https://www.accessdata.fda.gov/cdrh_docs/pdf17/P170002S048D.pdf. Approved 09/18/2025.
- U.S. Food and Drug Administration. Evolysse Form and Evolysse Smooth Patient Information (P240022). https://www.accessdata.fda.gov/cdrh_docs/pdf24/P240022D.pdf. Approved 02/13/2025.
- American Academy of Dermatology. Fillers: FAQs. https://www.aad.org/public/cosmetic/wrinkles/fillers-faqs. Accessed 10/06/2026.
- Jones DH, et al. Preventing and Treating Adverse Events of Injectable Fillers: Evidence-Based Recommendations From the American Society for Dermatologic Surgery Multidisciplinary Task Force. Dermatologic Surgery. 2021;47(2):214–226. https://www.asds.net/Portals/0/PDF/asdsa/Preventing%20and%20Treating%20Adverse%20Events%20of%20Injectable%20Fillers%20Evidence-Based%20Recs%20From%20ASDS%20Task%20Force%20Article.pdf.
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