Written and medically reviewed by Dr. Kamen Ng. Last reviewed 2026-08-26. 11 min read
The question I am asked, and why it is the wrong one
The question is almost always "which one is best". It is the wrong question, and answering it directly does patients a disservice, because these three products are not competing to do the same job.
They are grouped together because all three stimulate collagen rather than simply occupying space. Beyond that they differ in what happens on the day, what happens over six months, where in the tissue they belong, how long they last, and one thing that patients almost never ask about but should: what can be done if something goes wrong.
That last point is where I will spend the most time.
What each one actually is
| Radiesse | Sculptra | HArmonyCa | |
|---|---|---|---|
| Active material | Calcium hydroxyapatite microspheres, 25 to 45 microns | Poly-L-lactic acid microparticles | Calcium hydroxyapatite microspheres, 25 to 45 microns, at 55.7 per cent |
| Carrier | Carboxymethylcellulose gel | Reconstituted in sterile water, diluted by the injector | Cross-linked sodium hyaluronate gel, with lidocaine |
| Presentation | Prefilled syringe | Vial requiring reconstitution | Prefilled syringe, no reconstitution |
| Immediate volume | Yes, from the gel carrier, which then resorbs | No | Yes, from the HA component |
| Collagen response | Over weeks to months | Over three to six months | Over weeks to months |
| Typical course | One session, sometimes two | Three sessions, four to six weeks apart | One session, sometimes two |
| Reversibility | None | None | Partial. The HA can be dissolved, the CaHA cannot |
Radiesse
Calcium hydroxyapatite microspheres suspended in a gel carrier. The gel gives an immediate correction that gradually resorbs over the following weeks, while the microspheres act as a scaffold for fibroblast ingrowth and new type I collagen. The result you see at three months is your own tissue, not the product.
Radiesse has high projection capacity, which makes it useful where structural support is wanted: the jawline, chin, temples and lateral cheek. It can also be hyper-diluted and placed more superficially to work on skin quality rather than shape, which is a quite different use of the same product and one I have written about separately.
Sculptra
Poly-L-lactic acid, supplied as a powder and reconstituted before injection. There is no meaningful immediate result. Whatever you see on the day is the diluent and the swelling, and both are gone within days. This surprises patients who have not been warned, which is why I warn them at length.
The correction builds gradually as PLLA particles provoke a controlled foreign-body response and collagen deposition. It is inherently a course rather than a session, typically three treatments spaced four to six weeks apart, and the outcome is assessed months after the last one.
Sculptra is a diffuse volumiser. It restores generalised facial volume across an area rather than sculpting a defined edge. Patients who want a sharper jaw angle are usually asking for a different product.
HArmonyCa
The newest of the three, and a genuine hybrid rather than a marketing hybrid. It consists of CaHA microspheres of 25 to 45 microns at a concentration of 55.7 per cent, suspended in a non-animal cross-linked sodium hyaluronate gel, with lidocaine, supplied in prefilled syringes requiring no reconstitution. It is intended for deep dermal and subdermal placement in the mid and lower face, and its use has been extended to the dorsum of the hand.
The design logic is straightforward. The HA delivers immediate lift; the CaHA delivers the sustained collagen response afterwards. In the published case series the early clinical change comes mainly from the cross-linked HA and secondarily from the CaHA, with the CaHA microspheres providing the longer-term effect through regional collagen synthesis. New collagen fibre production has been described as beginning about a week after treatment, with associated remodelling of the extracellular matrix.
Reversibility: the difference nobody asks about
Every patient asks about downtime. Almost nobody asks what happens if the result is wrong, or if there is a vascular complication.
This is the most consequential difference between the three.
Hyaluronic acid fillers are reversible. Hyaluronidase degrades them. If a vessel is occluded, or the result is lumpy or overfilled, there is an antidote and it works within hours.
Radiesse is not reversible. Neither is Sculptra. There is no enzyme that dissolves calcium hydroxyapatite or poly-L-lactic acid. If either is placed badly, the options are massage, time, intralesional steroid for a nodule, or in some cases surgical removal. If either causes a vascular event, the standard rescue is unavailable.
HArmonyCa is partially reversible, and the qualifier matters. The hyaluronic acid component can be broken down by hyaluronidase. The CaHA component cannot, and attempts to dissolve it after the fact will not fully clear it. So a portion of what was injected can be retrieved and a portion cannot.
I raise this because "partially reversible" is being marketed in some quarters as though it were the same as reversible. It is not. It is better than nothing in an adverse event and I regard it as a genuine advantage of the product. It is not the same safety margin as a pure HA filler, and any patient choosing on the basis of reversibility should understand what they are actually getting.
This is also why placement discipline matters more with all three of these than with HA. The margin for error is smaller because the correction mechanism is weaker.
Where the evidence sits, honestly
Radiesse and Sculptra both have long clinical histories and substantial published use across many years and many indications.
HArmonyCa is newer and its evidence base is correspondingly thinner. Much of the published work consists of small case series and non-randomised studies. One frequently cited prospective, non-randomised study followed 15 women treated in the preauricular region, reporting volumetric change at 180 days along with increased collagen on elastography, and adverse effects that were largely mild. That is encouraging, and it is a small uncontrolled study.
There is also a legitimate open question in the literature. The rationale for combining CaHA with HA is partly to improve safety in a non-reversible product class, but reviewers have noted that it remains unsettled whether the combination actually delivers superior volumisation compared with HA alone. A randomised comparison of pure HA against the HA-CaHA combination for temporal volumisation has been conducted precisely because that question is open.
I use HArmonyCa and I think it is a well-designed product. I am not going to tell you the evidence for it currently matches that for Radiesse, because it does not.
How I actually choose
The decision is driven by the problem in front of me, not by product preference.
Diffuse volume loss across the mid and lower face, patient willing to wait. Sculptra. It restores generalised volume in a way the other two do not, and the gradual onset produces changes that friends and family register as looking well rather than as having had something done. The trade is patience and a three-session commitment.
Structural work needing definition and projection. Radiesse. Jawline, chin, temples. Its projection capacity and firmness are the reason. Also my choice where I want a defined edge rather than a diffuse fill.
Visible change on the day plus collagen afterwards, in the mid or lower face. HArmonyCa. The single-session convenience and no reconstitution are practical advantages, and the immediate HA component addresses the most common complaint about Sculptra, which is that nothing appears to happen for two months.
Skin quality rather than shape. Hyper-diluted CaHA placed differently, or polynucleotides, or skin boosters. None of these three products in their standard form is the answer to dull, crêped or thin skin.
Volume that must be reversible, or a high-risk anatomical zone. A hyaluronic acid filler, not a biostimulator. This includes the tear trough, which I do not treat with any of these three.
Lips. None of the above. Not Radiesse, not Sculptra, not HArmonyCa.
Most faces need more than one thing, and biostimulators layer well with HA and with each other when sequenced properly. What they do not do is substitute for one another. How those decisions are made in practice is set out in our biostimulation method.
Risks, and how they differ
Nodules are the risk that defines this product class, and the mechanism differs between them.
With Sculptra, nodules and papules classically arise from insufficient dilution, placement that is too superficial, or injection into areas of high mobility. The mitigations are well established: generous dilution, adequate reconstitution, deep placement in the subcutaneous or supraperiosteal plane, avoiding thin and mobile tissue, and post-treatment massage. Handled properly the risk is low. Handled casually it is not.
With Radiesse, nodules relate mainly to superficial placement or injection into mobile tissue, which is why it is contraindicated in the lips.
With HArmonyCa, the same principles apply, with the added consideration that the CaHA fraction is what persists if a nodule forms.
Vascular occlusion is the serious risk shared by all injectables. As discussed above, the rescue options are more limited here than with HA, which is an argument for anatomical caution and for cannula use in appropriate planes.
Other effects: bruising, swelling, tenderness, and with Sculptra a period during which the treated area feels firm to the patient before it settles.
Poor candidates include patients with very thin skin over the intended area, active inflammatory or infective skin disease, a history of hypertrophic scarring or granulomatous conditions, autoimmune disease of relevance, and anyone who is pregnant or breastfeeding. Patients with unrealistic expectations of speed are poor candidates for Sculptra specifically.
Disclose everything previously injected, including work done elsewhere and anything you cannot name. Layering a biostimulator over an unknown permanent product is a genuinely bad idea, and it is one of the more common problems I see in patients arriving from other clinics.
Two questions worth asking before treatment
Which product, and is it registered here? All three are regulated products. You are entitled to know exactly which one is being used and to see the packaging. The Medical Device Authority maintains a public register, and the same verification logic applies to injectables as to devices.
How many sessions, and what does the full course cost? This matters disproportionately for Sculptra, where a single vial is not a treatment and a quoted per-vial price is not a quoted course price. Compare complete courses, not unit prices. Our prices are published openly.
The summary I give in clinic
Sculptra restores volume you have lost, gradually and diffusely, and asks for patience and three visits.
Radiesse builds structure and definition, in one visit, and cannot be undone.
HArmonyCa gives you something on the day and collagen afterwards, in one visit, with part of it retrievable and part of it not, and with a shorter evidence record than the other two.
None of them is best. The right one depends on which of those descriptions matches the problem you actually have, and that is what an assessment is for.
References
- Journal of Aesthetic Nursing. HArmonyCa: a first-in-class, hybrid, dual-functioning hyaluronic acid and calcium hydroxyapatite dermal filler
- A randomised clinical trial comparing pure hyaluronic acid to the hyaluronic acid and calcium hydroxylapatite combination for temporal volumisation
- Allergan Aesthetics, HArmonyCa product information
- Malaysia Medical Device Register, public search at mmdr.mda.gov.my
Frequently asked questions
Sculptra generally has the longest duration, commonly quoted at around two years, but it requires a full course to get there. Radiesse and HArmonyCa are typically in the region of twelve to eighteen months. Individual variation is considerable and depends on the area treated, the volume placed and your own collagen turnover.
No. Neither has a reversal agent. There is no enzyme that dissolves calcium hydroxyapatite or poly-L-lactic acid. This is the most important practical difference between biostimulators and hyaluronic acid fillers, and it should be part of the decision rather than a footnote to it.
Partially. The HA component can be broken down by hyaluronidase; the CaHA component cannot be fully dissolved. That is a meaningful advantage over a pure CaHA product and it is not equivalent to the reversibility of an HA filler. Any patient choosing on the basis of reversibility should understand what they are actually getting.
Because there is no filling material. What is injected provokes your own collagen production over subsequent months, and the diluent that provides the appearance of correction on the day resorbs within days. Anyone promising immediate Sculptra results is describing swelling.
No. None of these three products belongs in the lips. For the tear trough I use hyaluronic acid where treatment is indicated at all, because reversibility matters most in exactly that location.
Yes, and combination is common. Biostimulators layer with HA fillers and with each other when sequenced deliberately, with appropriate intervals and correct planes. What matters is that each product is doing the job it is suited to. What they do not do is substitute for one another.
Usually Radiesse, for its projection and firmness, sometimes combined with a structural HA filler. Sculptra is the wrong tool for a defined edge; it restores generalised volume rather than sculpting a contour.
Sculptra is inherently a course, typically three sessions four to six weeks apart. Radiesse and HArmonyCa are usually one session, sometimes two. This matters when comparing quotes: a per-vial price for Sculptra is not a course price. Compare complete courses rather than unit prices.
This article is for general information and does not replace individual medical advice. All injectable treatments carry risks, including vascular complications. Injectable bio-stimulators are devices registered with the Medical Device Authority and administered only by appropriately trained and registered medical practitioners. Suitability, technique and outcomes vary between individuals and no result can be guaranteed.