Biostimulators Explained — Sculptra, Radiesse, and Beyond

Last updated: 5 March 2026

Medically reviewed by Dr Elena Vasquez, MSc, MBBS, Aesthetic Medicine Specialist with advanced training in biostimulatory treatments and collagen induction therapies.

The world of injectable aesthetics has expanded far beyond traditional dermal fillers. Biostimulators represent a fundamentally different approach to facial rejuvenation — rather than simply adding volume, they stimulate the body’s own collagen production for gradual, natural-looking restoration. This guide examines the leading biostimulatory products available in the UK and what patients can expect.

What Are Biostimulators?

Biostimulators (also called collagen stimulators) are injectable products that trigger a controlled inflammatory response in the skin, prompting fibroblasts to produce new collagen, elastin, and other extracellular matrix components. Unlike hyaluronic acid fillers which provide immediate volume, biostimulators work gradually over weeks to months, producing results that can last significantly longer.

“The beauty of biostimulators lies in their mechanism,” explains Dr Vasquez. “We are essentially harnessing the body’s own regenerative capacity. The results develop naturally because it is the patient’s own collagen being produced, not an external filler material.”

Sculptra (Poly-L-Lactic Acid / PLLA)

Sculptra has been used in aesthetic medicine since receiving CE marking in 1999, with FDA approval following in 2004 for lipoatrophy and 2009 for cosmetic use. It is composed of poly-L-lactic acid, a biocompatible, biodegradable synthetic polymer that has been used in dissolvable sutures for decades.

How Sculptra Works

Once injected, the PLLA microparticles create a scaffold within the deep dermis and subcutaneous tissue. The body recognises these particles as foreign and mounts a controlled inflammatory response, recruiting macrophages and fibroblasts. Over 6-12 weeks, new type I and type III collagen is deposited around the PLLA particles, which themselves gradually dissolve over approximately 24 months.

A pivotal study by Fitzgerald et al. (2018) in the Journal of Drugs in Dermatology demonstrated collagen formation persisting for up to 25 months following Sculptra treatment, with measurable skin thickness increases confirmed by ultrasound assessment.

Treatment Protocol

• Typically requires 2-3 treatment sessions, spaced 4-6 weeks apart
• Results develop gradually over 3-6 months
• Longevity: approximately 2-3 years
• Best suited for: temple hollowing, mid-face volume loss, pre-jowl hollows, overall facial volume restoration

Radiesse (Calcium Hydroxylapatite / CaHA)

Radiesse contains calcium hydroxylapatite microspheres suspended in a carboxymethylcellulose gel carrier. CaHA is a mineral compound naturally found in bone and teeth, making it highly biocompatible. It has CE marking and FDA approval for both aesthetic and reconstructive applications.

How Radiesse Works

Radiesse provides both immediate volumisation (from the gel carrier) and long-term biostimulation (from the CaHA microspheres). The gel carrier provides instant lift and is gradually absorbed over several weeks, while the CaHA microspheres stimulate neocollagenesis over 3-6 months before being metabolised into calcium and phosphate ions.

A landmark study published in Dermatologic Surgery (2015) showed that Radiesse increased dermal collagen content by approximately 30% at 6 months post-treatment, with improvements sustained beyond the resorption of the product itself.

Hyperdilute Radiesse

An increasingly popular technique involves diluting Radiesse with saline and/or lidocaine to create a thinner, more spreadable formulation. This “hyperdilute” Radiesse is used for skin quality improvement rather than volumisation, treating areas such as the neck, décolletage, arms, hands, and abdomen.

• Typically requires 2-3 sessions, spaced 4-8 weeks apart
• Standard Radiesse results last 12-18 months
• Hyperdilute results last approximately 12 months
• Best suited for: cheeks, jawline, chin (standard); skin quality improvement (hyperdilute)

Ellansé (Polycaprolactone / PCL)

Ellansé is a newer biostimulator composed of polycaprolactone microspheres in a carboxymethylcellulose carrier gel. Available in four formulations (S, M, L, and E) with varying longevity profiles, it offers practitioners the ability to tailor treatment duration to patient preferences.

Duration Options

• Ellansé S: Approximately 1 year
• Ellansé M: Approximately 2 years
• Ellansé L: Approximately 3 years
• Ellansé E: Approximately 4 years

A multi-centre study by de Melo et al. (2017) in the Journal of Clinical and Aesthetic Dermatology demonstrated sustained collagen production with Ellansé M for up to 24 months, with patient satisfaction scores remaining above 85% throughout the study period.

Emerging Biostimulators

Profhilo

Whilst technically a hyaluronic acid product, Profhilo functions as a bioremodeller rather than a traditional filler. Its unique formulation contains one of the highest concentrations of HA available (64mg/2ml) in a hybrid cooperative complex of high and low molecular weight HA. It spreads across tissue planes, providing hydration and stimulating collagen, elastin, and adipocyte stem cells.

Polynucleotide (PN) Products

Products derived from salmon or trout DNA (such as Ameela or Nucleofill) represent the latest category of biostimulatory injectables. Polynucleotides stimulate fibroblast activity, improve tissue hydration, and have antioxidant properties. Early clinical data suggests promising results for skin quality improvement, particularly around the eyes.

Choosing the Right Biostimulator

The choice of product depends on several factors:

• Treatment goal: Volume restoration (Sculptra, Radiesse, Ellansé) vs. skin quality (Profhilo, hyperdilute Radiesse, PNs)
• Desired longevity: From 6 months (Profhilo) to 4+ years (Ellansé E)
• Treatment area: Some products are better suited to specific anatomical regions
• Patient preference: Gradual results vs. some immediate effect
• Budget: Longer-lasting products may offer better value despite higher initial cost

“There is no single best biostimulator,” emphasises Dr Vasquez. “The optimal choice depends entirely on the individual patient’s anatomy, goals, lifestyle, and preferences. Often, a combination approach using different products in different areas produces the most harmonious results.”

Safety Profile

Biostimulators have an excellent safety record when used appropriately. Common side effects include injection-site swelling, redness, and bruising — typically resolving within 1-2 weeks. The most significant consideration is that unlike HA fillers, most biostimulators cannot be dissolved if placed incorrectly. This makes practitioner expertise and anatomical knowledge absolutely critical.

Nodule formation (small, palpable lumps) is the most commonly reported adverse event specific to biostimulators. A meta-analysis in the Aesthetic Surgery Journal (2020) reported nodule rates of approximately 5-7% for Sculptra, though modern dilution protocols and injection techniques have significantly reduced this incidence.

Frequently Asked Questions

How many sessions of biostimulator treatment do I need?

Most biostimulators require 2-3 treatment sessions spaced 4-8 weeks apart for optimal results. Profhilo typically requires 2 sessions one month apart. Your practitioner will create a personalised treatment plan based on the degree of volume loss, your goals, and the product selected.

When will I see results from biostimulator treatments?

Results develop gradually as new collagen is produced. Most patients notice initial improvements within 4-6 weeks, with optimal results visible at 3-6 months after completing the treatment course. This gradual improvement is often preferred by patients who want natural-looking enhancement without sudden, obvious change.

Can biostimulators be combined with dermal fillers?

Yes, biostimulators and hyaluronic acid fillers can be used as part of a comprehensive treatment plan. For example, a practitioner might use Sculptra for overall facial volume restoration whilst using HA fillers for precise lip augmentation or tear trough correction. These are typically performed in separate sessions spaced several weeks apart.

Are biostimulators suitable for younger patients?

Biostimulators can be appropriate for patients in their late 20s and 30s as a preventative measure, particularly skin quality treatments like Profhilo. For volumising biostimulators, they are most commonly used in patients from their late 30s onwards when collagen loss and volume depletion become more apparent.