What Are Injectables: Neuromodulators, Fillers, and Biostimulators Defined

Cosmetic injectables are treatments placed under the skin with a fine needle or a blunt cannula to soften lines, restore volume, or prompt the skin to build its own collagen. The word covers three types with three different jobs: neuromodulators, which relax the muscles that fold lines into the skin; dermal fillers, which add volume where it has gone; and biostimulators, which are placed to encourage new collagen over the months that follow. Each type works differently, lasts a different length of time, and suits a different concern, so an injector plans them together instead of asking one to do every job.

The three types at a glance

Neuromodulators

What they are: A purified protein, botulinum toxin type A, injected into a muscle to relax it.

What they are aimed at: Lines made by expression: frown lines, forehead lines, crow’s feet, and vertical neck bands.

How long they last: About three to four months for frown lines, with retreatment no sooner than three months apart.

What we carry: Botox, Daxxify, and Jeuveau.

Learn more: Botox in Fresno

Dermal fillers

What they are: A soft gel, most often hyaluronic acid, placed under the skin to smooth a fold or restore volume.

What they are aimed at: Folds and wrinkles such as the lines beside the nose, and volume in areas such as the cheeks and lips.

How long they last: It varies by product, area, and person. In the RHA studies, most people still showed improvement in their folds more than a year after treatment.

What we carry: RHA and Evolysse.

Learn more: Dermal fillers in Fresno

Biostimulators

What they are: An injectable that is absorbed over time and may prompt the body to produce new collagen where it was placed.

What they are aimed at: Gradual improvement in folds, wrinkles, and areas of volume loss, built over a series of sessions.

How long they last: In the Sculptra studies, results lasted up to about two years for some people.

What we carry: Sculptra, and Radiesse in a diluted form.

Learn more: Sculptra in Fresno

What a neuromodulator is

A neuromodulator is a prescription medicine made from botulinum toxin type A. Injected in small, measured doses into a specific muscle, it blocks the signal from the nerve to that muscle, so the muscle stops contracting as hard and the line it was folding into the skin softens. The effect is temporary. Nerve signaling returns over the following months, the muscle moves fully again, and the line comes back unless the treatment is repeated.

Three products sit in this class at Savage Serenity: Botox, Daxxify, and Jeuveau. All three are the same type of protein, prepared differently by different makers, and each is dosed in its own units. A unit of one product is not a unit of another, so doses are never compared number to number across brands. For frown lines, the effect of Botox lasts about three to four months, and retreatment waits at least three months from the last appointment. Results take days to appear, not minutes, which is why we book a follow up look after the first treatment.

What a neuromodulator does not do matters as much as what it does. It does not fill a line that is present when your face is at rest, it does not add volume, and it does not change skin texture. A deep fold beside the nose, a hollow cheek, or thinning skin is a different conversation, and usually a different injectable. Our guide to what a neuromodulator is goes deeper into dosing, onset, and the lines it suits. If you are planning a first visit, read what happens at a Botox appointment and how to prepare for wrinkle relaxer injections.

What a dermal filler is

A dermal filler is a soft gel implant placed under the skin to smooth a fold or restore volume. Fillers are regulated as medical devices, product by product and area by area: a gel that may be used in the folds beside the nose is not automatically permitted in the lips or the cheeks, and an injector chooses the product for the area as much as for the concern.

Most fillers, including the two lines we carry, are made of hyaluronic acid, a sugar that is already present in the body’s tissues. The gel is absorbable, meaning the body breaks it down over time, and the result fades with it. Other filler materials exist, including calcium hydroxylapatite, a mineral found in teeth and bone, and poly-L-lactic acid, a biodegradable polymer. Those two materials are the basis of the biostimulators described in the next section.

We carry RHA and Evolysse. Both are hyaluronic acid gels with lidocaine, a local anesthetic, mixed in, which is part of why a filler appointment is more comfortable than most people expect. A filler result is visible the day it is placed and settles as swelling goes down. In the RHA studies, more than 70 percent of injection site responses had resolved within a week and more than 85 percent within two weeks, and most people still showed improvement in their folds more than a year after treatment. Lip filler is its own appointment with its own rules; read about lip filler in Fresno before you book it.

What a biostimulator is

A biostimulator is an injectable placed to encourage the body to make its own collagen where it was injected, in place of a gel that holds the space itself. The name is a clinical grouping, not a regulatory category; the products in it are regulated as dermal fillers. What sets them apart is how the result arrives. A hyaluronic acid filler shows its result the day it is placed. A biostimulator builds its result over several weeks as the material is absorbed and new collagen may form in its place.

Sculptra is the biostimulator we use most. It is made of poly-L-lactic acid, and as the beads biodegrade the body may produce new collagen where it was injected. Treatment is a series, one to four sessions and typically three, spaced several weeks apart, and the improvement is gradual over the weeks after each one. In the clinical studies the result lasted up to about two years for some people. Sculptra also has its own aftercare: the treated area is massaged for five minutes, five times a day, for five days. Radiesse, a calcium hydroxylapatite filler, is often grouped with the biostimulators as well; we offer it in a diluted form, and your injector will discuss where it fits in a plan.

Where PRF fits

PRF, platelet rich fibrin, is a fourth injectable we offer, and it is different in kind from the three above. It is made from your own blood: a small amount is drawn, spun to concentrate the platelets, and injected back, prepared without additives. The research on platelet treatments for the skin is still developing, and the American Academy of Dermatology describes platelet rich plasma, PRF’s closest relative, as still an unproven treatment. We say so plainly, and your injector will tell you what the current evidence supports. Read more about PRF injectables in Fresno.

What each product is approved for

Every product we inject is FDA approved for specific lines or areas: Botox for frown lines, crow’s feet, forehead lines, and vertical neck bands; Daxxify and Jeuveau for frown lines; RHA and Evolysse for facial wrinkles and folds such as the folds beside the nose, in adults 22 and older; and Sculptra for the folds beside the nose and other facial wrinkles, and for fine lines and wrinkles in the cheeks. Your injector matches the product to your anatomy and your concern at the consultation.

How the three types differ, and how they combine

Lines that move and lines that stay

Neuromodulators address lines that appear when you make an expression and fade when your face is still. Fillers address folds and hollows that are present at rest. Biostimulators address the gradual thinning of the skin and loss of volume that comes with age, over a longer stretch of time. The first question your injector asks is which of those three you are seeing, because the answer points to the type before it points to a product.

How fast each one works, and how long it holds

A neuromodulator takes days to show and holds for months. A hyaluronic acid filler shows the same day and, for folds, held for more than a year in most people in the RHA studies. A biostimulator takes weeks to build and, in the Sculptra studies, held up to about two years for some people. Those differences shape the plan: a neuromodulator is a standing appointment every few months, a filler is an occasional one, and a biostimulator is a series followed by a long gap.

Combining them

Most faces call for more than one type, and the types are planned together. Angela puts it this way: “My approach is always full facial balancing rather than chasing one line or treating one area in isolation. 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.” In practice that often means a neuromodulator in the upper face, a filler where volume has gone, and a biostimulator where the skin itself has thinned, sequenced across more than one visit so each result can be judged on its own.

Risks, and what every injectable has in common

Every injectable is a medical treatment delivered with a needle, and every one carries some risk. The common effects are the ones you would expect from an injection: bruising, swelling, tenderness, and redness at the site, which usually fade over days to a couple of weeks. Neuromodulators can also cause a headache or a temporary droop of the brow or eyelid when the product affects a nearby muscle.

The serious risks differ by type, and we name them because you should know them before you book. For neuromodulators, the Medication Guide for Botox says the product may cause serious side effects that can be life threatening, including problems breathing or swallowing and spread of toxin effects, and that these problems can happen hours, days, to weeks after an injection. For fillers, including Sculptra, the most serious risk is unintentional injection into a blood vessel; the chance is very small, and the complications can be serious and permanent, which is why a filler injector studies facial anatomy in depth. Sculptra has one risk of its own: lumps and bumps, called nodules, that mostly occurred several months after injection in the studies, starting from one to two months and up to fourteen months after the last session.

Call the clinic, or get medical help right away, if after any injectable you notice:

• problems swallowing, speaking, or breathing
• changes in your vision
• signs of a stroke, such as 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
• unusual pain during or shortly after treatment

Tell us before treatment if you have severe allergies, a bleeding disorder, an infection or active breakout where you would be injected, or a muscle or nerve condition, and if you are pregnant or breastfeeding, so your injector can plan around it. Results vary from person to person, and no injectable result is guaranteed.

Who performs injectables at Savage Serenity

Angela Hash, BSN, RN, leads the practice and trains the injector team in her facial balancing approach. Michelle Perkins, RN, and Candice Brantley, NP, perform injectables alongside her. Dr. Luis Lee is the practice’s medical director and supervising physician. Every treatment begins with a consultation with your injector, who watches how your face moves and where volume has changed before any product is chosen.

What injectables cost

Pricing follows the type. Neuromodulators are priced by the unit, so the cost follows the dose your plan calls for. Fillers are priced by the syringe, and a biostimulator plan is priced by the amount used and the number of sessions in the series. We tell you the plan and the price before anything is injected, and financing options are available for larger plans.

Frequently asked questions about injectables

What are injectables, and are they the same thing as Botox?

Injectables are the treatments placed under the skin with a needle or cannula: neuromodulators, dermal fillers, and biostimulators. Botox is one neuromodulator, and neuromodulators are one of the three types of injectables. Patients often say Botox for the whole category, the way a brand name stands in for a product, but a filler and a biostimulator are different materials with different jobs, and neither relaxes a muscle.

Are injectables permanent?

None of the injectables we offer is permanent. Neuromodulators wear off over months, hyaluronic acid fillers are absorbed over a year or more, and biostimulator results, which build over a series, lasted up to about two years for some people in the studies. Maintenance is part of every plan, and your injector will tell you what to expect for yours.

Can the three types be combined?

Yes, and they usually are. Some combinations happen in the same appointment and others are spaced across visits so each result can settle and be judged before the next step. Your injector decides the order and the spacing from your anatomy and your plan.

Which injectable is right for me?

It depends on what you are seeing. Lines that show when you move point to a neuromodulator, folds and hollows that are there at rest point to a filler, and thinning skin or broad volume loss points to a biostimulator or a series. A consultation determines which type and which product fit you, and often the answer is more than one.

Do injectables hurt?

Most people describe a brief pinch. Neuromodulator needles are very fine, and the fillers we carry contain lidocaine, a local anesthetic, so the area becomes more comfortable as the treatment goes on. Ask your injector about numbing options when you book.

Book a consultation in Fresno

Bring the concern, and we will tell you which type of injectable addresses it, which product we would use, and what it would cost. Request a consultation at our Fresno studio, or call or text the front desk.

Keep reading

• Injectables at Savage Serenity
• What happens at a Botox appointment
• How to prepare for wrinkle relaxer injections
• How Botox works
• Hyaluronic acid fillers versus Sculptra
• About Angela Hash, BSN, RN

Sources

• U.S. Food and Drug Administration. Botox Cosmetic (onabotulinumtoxinA) Prescribing Information (BLA 103000). https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/103000s5316s5319s5323s5326s5331lbl.pdf. Revised 10/2024.
• U.S. Food and Drug Administration. Medication Guide, Botox Cosmetic (onabotulinumtoxinA). DailyMed. https://dailymed.nlm.nih.gov/dailymed/medguide.cfm?setid=485d9b71-6881-42c5-a620-a4360c7192ab. Revised 10/2024.
• U.S. Food and Drug Administration. Daxxify (daxibotulinumtoxinA-lanm) Prescribing Information (BLA 761127). DailyMed. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=3aaa6e14-a3f7-4fb2-b9f9-d3a9c3ae1f74&type=display. Revised 11/2023.
• U.S. Food and Drug Administration. Jeuveau (prabotulinumtoxinA-xvfs) Prescribing Information (BLA 761085). DailyMed. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=17a914c1-e54b-4b50-965d-b0fd9111bba4&type=display. Revised 04/2023.
• U.S. Food and Drug Administration. RHA 2, RHA 3, RHA 4 Instructions for Use (P170002). https://www.accessdata.fda.gov/cdrh_docs/pdf17/P170002C.pdf. Approved 10/19/2017.
• U.S. Food and Drug Administration. Evolysse Form and Evolysse Smooth Instructions for Use (P240022). https://www.accessdata.fda.gov/cdrh_docs/pdf24/P240022C.pdf. Approved 02/13/2025.
• U.S. Food and Drug Administration. Sculptra Patient Labeling (P030050/S039). https://www.accessdata.fda.gov/cdrh_docs/pdf3/P030050S039D.pdf. Approved 04/25/2023.
• 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.
• American Academy of Dermatology. Platelet-rich plasma: the secret to younger-looking skin? https://www.aad.org/public/cosmetic/younger-looking/platelet-rich-plasma-secret-to-younger-skin. Accessed 10/06/2026 (page undated).