Calcium hydroxylapatite (CaHA)
Calcium hydroxylapatite (CaHA, also called calcium hydroxyapatite) is a mineral used as particles suspended in a carrier gel. It differs from hyaluronic acid. Certain formulations are used for volume or contour and are also discussed for collagen-related effects. The precise formulation and proposed use should be identified before those claims are applied to you.
What the label does not tell you
Undiluted, diluted and hyperdiluted treatments are not interchangeable promises. The ingredient name does not establish that the planned dilution, injection site or technique is authorised or supported. The American Society for Dermatologic Surgery specifically excludes lip augmentation from the uses of CaHA described on its patient page. Do not assume that every filler can be used in the lips or reduced in the same way as HA.
Questions to bring
Is the aim volume, contour or a skin-quality change and what supports that aim? Does the product’s intended use cover this site and proposed preparation? How would nodules or a vascular complication be recognised and managed? What are the limitations if I later want the material reduced or removed?
Evidence and scope
Regulatory indications belong to a product and jurisdiction; they do not apply automatically to every CaHA preparation. US FDA approval applies to an exact product and indication; authorisation in the treatment country must be checked separately.
Read the original sources
Sources describe specific products, studies or countries. They do not establish approval everywhere.
General education. Your clinician can assess your individual suitability. Rules depend on the treatment country; FDA references concern the United States. External sources may be in another language.