Dr Sin Yong · MBBS (NUS) · MRCS (Edin) · MSc Aesthetic Medicine (London) · MSc Practical Dermatology (Cardiff) · International KOL
Radiesse is calcium hydroxylapatite microspheres in a gel carrier. Undiluted, it fills on the day and stimulates collagen afterwards; diluted, it becomes a skin-quality treatment for the face, neck and body. Neither form is dissolvable — assessed and placed by Dr Sin Yong at Orchard Road, Singapore.
Radiesse is a suspension of calcium hydroxylapatite microspheres in a water-based gel. Calcium hydroxylapatite is the mineral that makes up bone and tooth enamel; here it is manufactured synthetically into smooth spheres between 25 and 45 microns across, which form roughly 30% of the syringe. The gel carrier — sodium carboxymethylcellulose, glycerin and water — is the other 70%.
Like Ellansé, it works in two phases. The gel provides correction on the day. As the gel is absorbed over the following weeks, fibroblasts respond to the microspheres by producing collagen around them, and that collagen carries the result once the gel has gone. The microspheres themselves are gradually broken down and metabolised.
What sets Radiesse apart from the other biostimulators is how far it has been studied in diluted form. Mixed with saline and lidocaine and placed in a thin layer close to the surface, it stops being a volumiser and becomes a treatment for skin quality across large areas — a different procedure using the same product.
The dilution decides what Radiesse is for, and the two uses should not be confused with each other.
Undiluted, or lightly diluted, it is a structural product. It is placed deep, on bone or in deep fat, in small amounts where projection or support is needed: the chin, the jawline, the pre-jowl area, the back of the hand. In this form it is firm and it is visible if placed too superficially, which is why it is kept away from thin, mobile skin.
Hyperdiluted, it is spread in a thin layer in the superficial subcutaneous plane across an area, usually with a cannula, to improve laxity and texture rather than to fill anything. A 2019 international consensus set out dilution ratios and depths for the face, neck, décolleté, arms, abdomen, thighs, buttocks and hands; the neck and the backs of the hands are among the more studied areas. The result is a change in skin firmness and quality that arrives gradually as collagen forms, not volume.
A clinic offering “Radiesse” may mean either. It is worth knowing which before you agree to anything.

Hyaluronidase dissolves hyaluronic acid filler and nothing else. It has no action on calcium hydroxylapatite or on the gel that carries it. A misplaced or excessive Radiesse result is managed, not erased.
There is one difference from the other biostimulators worth stating accurately. Intralesional sodium thiosulfate has been reported in the literature as a treatment for calcium hydroxylapatite nodules, with laboratory work showing it can degrade the material. It is an option for a nodule, not a way to reverse a treatment, and it is not routine. Calcium hydroxylapatite is also radio-opaque and clearly visible on ultrasound, which makes it one of the easier materials to identify when a previous injection needs to be assessed.
Problems from Radiesse placed elsewhere are assessed under filler correction, with imaging first.
“Radiesse is the one biostimulator that also fills on the day. That makes it easier to overdo, not harder.”
Dr Sin YongOn why immediate volume is a risk as much as a feature
Dr Sin Yong treats the two forms of Radiesse as two procedures with different plans, and does not mix them in one appointment without a reason.
For structure, he places undiluted product deep and sparingly — on the periosteum of the chin and jaw, or in the deep fat where the anatomy allows — reading the jawline as a line from chin to angle rather than as a set of points, and leaving the lower face lighter than a day-one judgement would suggest, because the collagen response adds to it later and cannot be removed.
For skin quality, he hyperdilutes according to the published consensus ranges, adjusted to the thickness of the skin in that area, and places it superficially with a cannula in a fan pattern so that the product is a thin even layer rather than a series of deposits. The neck and the backs of the hands are the commonest requests; the abdomen and inner arms after weight loss are the next. Where laxity rather than skin quality is the real complaint, he will say so and point to focused ultrasound or the 4K Body Lift instead.
Undiluted, it suits a patient who needs structural support in firm tissue — chin, jawline, lateral cheek, hands — and who wants some change on the day while choosing the product for the collagen that follows. Hyperdiluted, it suits crepey, lax skin on the neck, chest, arms, abdomen and hands in a patient who can wait for a gradual change in quality and who understands it is not a volume treatment.
It does not suit the lips, the tear troughs or the glabella, where a firm, non-dissolvable, radio-opaque material has no defensible place. It does not lift a descended plane: a jowl or a loose jawline is a laxity problem, and adding volume below it makes it heavier. And it is not the right first injectable in a face that has never been assessed; a reversible hyaluronic acid filler is the more forgiving start.
Against its neighbours: Sculptra gives almost nothing on the day and is used diffusely for deflation; Ellansé is the closest relative, immediate plus stimulating, but is less studied in diluted form. Which fits is decided by the anatomy and the goal, not by brand.

A face that has been injected more than once often arrives with a complaint that sounds like it needs more product — a heaviness in the lower face, a fullness under the eyes, a lump that has appeared months after the last visit. In Dr Sin Yong's experience the opposite is more often true: the problem is what is already there, and the answer is subtraction, not addition.
So before any further Radiesse is placed, he scans. High-frequency ultrasound shows what material is sitting in the tissue, how deep it is, whether it has migrated, and whether a lump is calcium hydroxylapatite, old hyaluronic acid filler, a cyst, or scar. Each of those is managed differently, and two of them are made worse by injecting on top. A scan takes minutes and changes the plan more often than not.
If the scan shows that less is what you need, that is a different procedure with its own planning — see filler correction. If it shows a clean field, Radiesse can be placed with confidence rather than hope. Either way, nothing is added to a face that has not been looked beneath.
The common findings are swelling, bruising and tenderness, and a temporary firmness where undiluted product sits. Nodules and visible or palpable product are the specific risks of a firm material placed too superficially; with hyperdiluted product the risk is more often unevenness or small nodules in thin skin. The serious risks are vascular and attend any injectable placed near facial vessels, which is why depth and anatomy matter more than the product.
Calcium hydroxylapatite is metabolised by the body over time and the collagen it produced ages with the rest of the skin. The change is not lifelong, and no duration quoted to you is a prediction for your anatomy.
de Almeida AT, Figueredo V, da Cunha ALG, et al. Consensus recommendations for the use of hyperdiluted calcium hydroxyapatite (Radiesse) as a face and body biostimulatory agent. Plastic and Reconstructive Surgery – Global Open 2019;7(3):e2160. source
US Food and Drug Administration. Radiesse® injectable implant: summary of safety and effectiveness data, P050037, December 2006. source
Robinson DM. In vitro analysis of the degradation of calcium hydroxylapatite dermal filler: a proof-of-concept study. Dermatologic Surgery 2018;44 Suppl 1:S5–S9. source
Wortsman X. Identification and complications of cosmetic fillers: sonography first. Journal of Ultrasound in Medicine 2015;34(7):1163–1172. source
Singapore Medical Council. Guidelines on Aesthetic Practices for Doctors, 2016 Edition. source
Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 2 October 2026
Undiluted and hyperdiluted Radiesse are different procedures for different complaints, and neither can be dissolved. Dr Sin Yong decides which, if either, fits before anything is placed.
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