What is CaHA?
CaHA stands for calcium hydroxylapatite, a mineral compound also found in bone and teeth. In aesthetic treatments it is used as small, smooth microspheres suspended in a gel carrier.
Calcium hydroxylapatite used in injectables is a synthetically produced form of a mineral compound that occurs naturally in the body. In injectable products it is added to a gel carrier as microspheres of a defined size. The gel provides volume and support at the time of treatment, while the microspheres act as a scaffold in the tissue. Over time both the gel and the microspheres are broken down and cleared by the body.
One widely used CaHA product is Radiesse by Merz. HArmonyCa by Allergan Aesthetics is a hybrid that suspends CaHA microspheres in a hyaluronic acid gel. The registration and traceability of these products in Türkiye should be checked before treatment. Which product is used, in which area, or whether one is used at all, is decided by the physician at an in-person assessment.
How does CaHA work as a biostimulator?
As the carrier gel is absorbed, the microspheres may stimulate nearby fibroblasts to produce collagen. CaHA is therefore associated with both early support and a gradual tissue response.
Most of the support seen in the first weeks after treatment comes from the carrier gel. As the gel is absorbed, the microspheres provide a surface for cells called fibroblasts and may stimulate them to produce collagen. Over time, this new tissue can take over part of the support the gel provided. The process is gradual, and its extent depends on your age, tissue quality and individual collagen response.
Used undiluted, CaHA is planned mainly for support and contour; diluted, it is planned mainly to support skin quality. In diluted use the product is spread in a thin layer over a wider area, and the effect may be built over several sessions. The two approaches can be combined in different areas within the same plan, and which suits you depends on the structure of the area and your skin.
How does CaHA differ from hyaluronic acid filler?
HA fillers add volume directly and can be dissolved with an enzyme. CaHA aims for support plus a collagen response and cannot be dissolved in the same way.
Hyaluronic acid fillers create volume with the cross-linked gel itself and can be dissolved with hyaluronidase if needed. That reversibility is regarded as an important safeguard, particularly in delicate areas such as the lips and under the eyes. CaHA has a denser, more supportive character and may be chosen for deep support points instead. Because the microspheres are not dissolved by hyaluronidase, planning is especially careful.
Neither class is universally superior; each suits different situations, and both can be used in different areas of the same plan. The choice takes into account the area, tissue thickness, the need for reversibility, previous treatments and your expectations. For visitors to Istanbul, this is one of the central topics of the in-person consultation, and the outcome may also be that no injectable is recommended.
Who may not be suitable for CaHA?
It is not used during pregnancy or breastfeeding, with active infection in the area or with a known allergy to its components. It is generally avoided in the lips and under the eyes.
Treatment is not carried out, or is postponed, during pregnancy and breastfeeding, with active infection, cold sores or inflammatory skin disease in the area, or with a known allergy to any component or to lidocaine. A tendency to keloid scarring, active autoimmune disease, bleeding disorders and blood thinners are also discussed. Thin, mobile areas such as the lips and tear troughs are generally avoided because of the risk of nodules.
Because CaHA may be visible on X-rays and some other imaging, it is advisable to mention the treatment before future scans. Areas previously treated with unknown fillers need careful assessment. With marked excess skin and advanced sagging, CaHA is not equivalent to a surgical facelift, and a surgical opinion may be suggested. All of this is discussed alongside your medical history in person.
What aftercare is needed, and what are the risks?
Most people return to normal activities the same day, with some swelling and bruising early on. Nodules and, rarely, vascular occlusion are possible, and CaHA cannot be dissolved with an enzyme.
Avoiding strenuous exercise, saunas, alcohol and pressure on the area for 24 to 48 hours is usually advised. After diluted treatment, brief massage may be recommended. Swelling in the first days settles over time, while the collagen-related change is assessed over weeks and months. A follow-up appointment allows the result and any irregularity to be reviewed, and specific aftercare instructions are given after treatment.
Common effects include swelling, redness, tenderness and bruising. Nodules may form, particularly in thin-skinned areas. Vascular occlusion is rare but serious; skin colour change, severe pain or visual disturbance require urgent attention. As CaHA cannot be dissolved with hyaluronidase, safety relies on careful choice of area, depth and technique, and these risks are discussed face to face beforehand.
Frequently asked questions
How long does CaHA last?
It varies with the product, the area, how it is used and your metabolism. Effects of around a year, and longer in some areas, are commonly reported for CaHA products; your likely duration is discussed at consultation.
Does CaHA stay in the body?
No. The carrier gel and the calcium hydroxylapatite microspheres are gradually broken down and cleared by the body, at a pace that varies from person to person.
How does CaHA compare with PLLA?
CaHA offers early support alongside a collagen response, whereas PLLA works more gradually and usually needs several sessions. A fuller comparison is on the PLLA page, and the choice is made at consultation.
Can I have an X-ray after CaHA treatment?
Yes, but because CaHA may be visible on X-rays and some other imaging, it is advisable to tell the doctor or radiographer about the treatment beforehand.
Where on the face is CaHA used?
On the face, CaHA is mostly used undiluted at deep support points such as the cheekbones, jawline, chin and temples. When diluted, it can be spread over wider areas such as the cheeks and lower face, and also the neck, to support skin quality. The lips, tear troughs and very thin-skinned areas are generally avoided because of the risk of visible or palpable nodules.
Can CaHA cause calcium build-up or bone formation in the body?
No, CaHA is not expected to cause bone formation where it is injected. Calcium hydroxylapatite microspheres are gradually broken down into calcium and phosphate ions, which are cleared through the body’s normal metabolism. The fact that CaHA can show up on X-rays does not mean bone has formed; that visibility simply comes from the mineral structure of the microspheres.
When can I have a facial massage or facial treatment after CaHA?
After CaHA, waiting at least one to two weeks before a professional facial massage, deep facial treatments or anything that presses on the area is usually advised. This gives the product time to settle and swelling time to subside. After diluted CaHA your physician may ask you to do a short massage; this differs from a general facial massage and should be done as shown.
When is CaHA repeated once the effect starts to fade?
A repeat CaHA treatment is often considered about a year or more after the first, once the support is seen to be fading. It is planned by assessing the support lost by then and any effect remaining from the previous treatment. As the collagen response may keep contributing support for a while, the amount used the second time need not match the first session.
Sources (4)
- Aesthet Surg J (Aguilera et al.): The Role of Calcium Hydroxylapatite (Radiesse) as a Regenerative Aesthetic Treatment: A Narrative Review (2023)
- Dermatol Surg (Goldie et al.; international panel incl. European experts): Global Consensus Guidelines for the Injection of Diluted and Hyperdiluted Calcium Hydroxylapatite for Skin Tightening (2018)
- U.S. FDA: Premarket Approval (PMA) P050037: RADIESSE
- Aesthet Surg J Open Forum (Moradi et al.): Guidelines for Optimal Patient Outcomes Using Calcium Hydroxylapatite for Jawline Contour (2023)
This content is for general information and does not replace a personal medical assessment.