Mechanism of Action

Radiesse is an injectable implant composed of smooth calcium hydroxylapatite (CaHA) microspheres (diameter of 25 µm to 45 µm) suspended in a sodium carboxymethylcellulose gel carrier.1 Radiesse is approximately 30% CaHA and 70% gel carrier by volume.

Radiesse is injected under the skin in a minimally invasive procedure. Injection of the product provides an immediate and visible correction to the wrinkle. There is no skin sensitivity testing or reconstitution required.1

Over time, the gel is absorbed, and fibroblasts appear.2,3 The process of neocollagenesis begins, stimulating the gradual growth of the patient’s own collagen.4 The collagen that forms results in extended correction and increased patient satisfaction. Radiesse builds structural scaffolding by stimulating collagen production for a year or longer.3,5,6

Histology slides at different intervals of time
Histology slides demonstrate deposition of new collagen around CaHA microspheres over an extended period of time. Collagen fibers stain red, while other tissue elements appear more yellow.

Radiesse stimulates collagen III, which is gradually replaced by collagen I. This creates a stable organized ration of collagen I and II with structure and support, compared to collagen type I stimulation alone.3-5

  • Collagen III stabilizes and organizes collagen I, ensuring its alignment and thickness7
  • By stimulating both, Radiesse results in youthful-looking skin3,5
graphic illustrating the benefits of collagen 1, collagen 3, elastin, proteoglycans, and angiogenesis.

The results are immediate, natural, and subtle. The correction is long-lasting but not permanent. Over time, the CaHA microspheres break down and are metabolized by the body’s normal processes.2,6,12

It is important to remember not to overcorrect (overfill) a contour deficiency with Radiesse because the depression should gradually improve within several weeks as the treatment effect of Radiesse occurs.

How It Works

Attend a Radiesse Boot Camp

During this training, attendees will have the opportunity to learn more about

  • Facial anatomy
  • Injection technique
  • Product mechanism of action
  • Potential treatment areas
  • Real patient results

Contact us if you would like more information about becoming a Radiesse provider.

Become a provider

Contact us if you would like more information about becoming a Radiesse provider.

Become A Provider


  1. Radiesse [Instructions for use]. Franksville, WI: Merz North America, Inc; 2023.
  2. Jansen DA, Graivier MH. Plast Reconstr Surg. 2006;118(suppl 1):22S-30S.
  3. Yutskovskaya Y, et al. J Drugs Dermatol. 2017;16(1):68-74.
  4. Aguilera SB, et al. Aesthet Surg J. 2023;43(10):1063-1090.
  5. Nowag B, et al. CaHA microspheres: contact with fibroblasts and amount of spheres are key factors for collagen stimulation. Presented at: AMWC 2020 Monte Carlo, Monaco: April 2-4, 2020.
  6. Moers-Carpi M, et al. Dermatol Surg. 2007;33(suppl 2):S144-S151.
  7. Liu X, et al. Proc Natl Acad Sci U S A. 1997;94(5):1852-1856.
  8. Yutskovskaya Y, et al. J Drugs Dermatol. 2014;13(9):1047-1052.
  9. Yutskovskaya YA, et al. J Drugs Dermatol. 2020;19(4):405-411.
  10. González N, et al. Dermatol Surg. 2019:45(4):547-551.
  11. Rovatti PP, et al. Dermatol Surg. 2020;46(12):e112-e117.
  12. Bass LS, et al. Aesthet Surg J. 2010;30(2):235-238.