An Aesthetic Practitioner’s Guide to Biostimulators

What are biostimulators? How do biostimulatory fillers differ from regular fillers or skin boosters? Here’s everything clinicians need to know about this evolving product category.

Biostimulatory fillers, more widely known as biostimulators are one of the fastest growing areas in aesthetic medicine. 

Patients increasingly value prevention and long-term skin quality outcomes, looking for youthful firmness and a smooth, even texture. And biostimulators are ready to meet these needs, whether this is through treating skin laxity, fine lines or volume loss, by encouraging the body to make its own collagen. 

Social media, practitioner education, and new product innovation are all fuelling this growth, so, for injectors, this shift is significant. 

Here we explore some of the common questions aesthetic practitioners have about biostimulatory fillers, including:

• What are biostimulators?
• How do they differ from hyaluronic acid-based fillers and skin boosters?
• What brand of biostimulators should I use in my aesthetic practice?
• Where are they used and how do you inject biostimulators?
• What is the complications profile for these products?

You can also scroll down to watch a live biostimulator treatment demonstration.

What are biostimulators?

In short, biostimulators are injectable products that stimulate the body’s natural production of collagen. Instead of replacing lost volume directly, they create controlled localised inflammation. Fibroblasts are then stimulated into building new collagen and elastin - the foundations of healthy, youthful skin.

This process can take several weeks or months, meaning results are gradual and natural-looking, but they’re also long-lasting. 

Biostimulators typically use molecules that are either synthetic and biodegradable or naturally occurring. Common ingredients include polycaprolactone, calcium hydroxyapatite, and poly-L-lactic acid. You can find out more about these ingredients in our 2024 article, What’s the Difference Between PLA, PDLLA, PDLA and PLLA Fillers? 

Once injected, these materials are slowly broken down and eliminated. But before they disappear, they leave behind new collagen that helps restructure the dermis.

The overall effect is an improvement in skin firmness, elasticity and surface skin quality. Patients often describe it as looking fresher, rather than “done.” 

Their method of action make biostimulators well-placed to tackle facial rejuvenation not just in ageing-related cases. But also with more modern concerns related to medically-assisted weight loss, such as ‘Ozempic Face’. 

What’s the difference between biostimulators and dermal fillers?

Although both are cosmetic injectables, they have very different actions, so first, let’s unpack these terms. ‘Biostimulators’ are an injectable gel, also known as ‘biostimulatory fillers’. They are, for all intents and purposes, a type of dermal filler - especially as ‘dermal filler’ simply means any gel that’s used to restore lost volume, enhance contours, or smooth wrinkles.

What’s typically meant by ‘dermal filler’ is hyaluronic acid-based filler. This is the most commonly used form of soft tissue filler in aesthetic procedures. 

The key differences between biostimulatory fillers and hyaluronic acid-based fillers are, as follows.

Hyaluronic acid-based fillers:

• Usually made from cross-linked hyaluronic acid
• Designed to restore lost volume, enhance features and/or contour the face
• Excellent at providing structural support
• Deliver immediate results with a life cycle dependent upon the treatment area and product used.

Biostimulatory fillers:

• Encourage the patient’s body to produce collagen over time
• Provide subtle, gradual skin improvements
• Excellent for improving skin laxity, texture and skin quality
• Deliver longer-lasting outcomes.

As you can see, it’s best not to view fillers and biostimulators as competitors. Each deserves a place in your aesthetic toolkit!

You can also supercharge the unique benefits each offers by combining fillers and biostimulators in multimodal treatment plans.

Combining fillers and biostimulators 

The pairing of soft tissue fillers with biostimulators can be incredibly impactful. Especially in cases of full face rejuvenation, which often requires more than one approach to see optimal results. 

Fillers can replace volume and restore contour, whilst biostimulators can improve skin quality and firmness. Together, they offer patients a more holistic treatment, with subtly striking results.

This approach also mirrors the way ageing occurs, as a combination of structural loss, skin laxity and textural change.

Patients appreciate the dual outcome this combination offers. They get the immediate visible changes from the fillers, along with progressive biostimulation. This satisfies any desire for ‘instant gratification’, without compromising on long-term benefits, and is just one of the reasons why multi-modal treatment plans are on the rise.

Popular biostimulators in the UK

There are several reputable biostimulatory filler products available to UK aesthetic practitioners. These three stand out as the most widely used in current practice, anecdotally.

Please note, we haven’t included HArmonyCA in the above list as it’s not technically a biostimulator. It’s a hybrid product that sits between a biostimulator and a traditional filler, developed by Allergan Aesthetics, and combines calcium hydroxyapatite microspheres with cross-linked hyaluronic acid.

1. Sculptra (Poly-L-lactic Acid)

Galderma’s Sculptra was one of the earliest biostimulators. It uses poly-L-lactic acid, a biodegradable synthetic polymer and has a very different rheology to dermal fillers. It comes as a powder that must be reconstituted with sterile water before use.

This preparation involves reconstitution at least several hours before injection, so planning is key. This allows the particles to fully hydrate.

Typically used for diffuse facial volume loss, skin laxity and hollowing, the product is injected using a tunnelling or fanning technique.

Large areas can be treated in one session, but results depend on a series of treatments.

Once injected, Sculptra particles stimulate fibroblast activity and collagen formation. The results emerge gradually, usually over three to six months, and can last for two years or more. 

2. Radiesse (Calcium Hydroxyapatite)

Radiesse is a Merz Aesthetics product made from calcium hydroxyapatite microspheres suspended in a gel carrier. It combines immediate filling with long-term stimulation and has a rheology that provides high viscosity and elasticity. This makes it suitable for deeper placement and structural support.

Injected subdermally, Radiesse initially offers an instant volumising effect. The gel then resorbs, leaving microspheres that stimulate new collagen over time.

It’s commonly used for treating the cheeks, jawline, chin and hands. However, it can also be used for treating moderate to severe facial folds.

Radiesse is supplied ready to use, with no reconstitution required. It’s administered using standard filler injection techniques, though deeper placement is usually preferred.

Its benefits include both immediate correction and sustained improvement. This allows patients to see results quickly but also continue to benefit for over a year.

3. Ellansé (Polycaprolactone)

Ellansé by Sinclair is a unique biostimulator using polycaprolactone microspheres in a carboxymethylcellulose (CMC) gel. There is a 70:30 CMC gel to polycaprolactone split.

This rheology allows it to act both as a dermal filler and as a collagen stimulator. The gel provides immediate correction, while microspheres drive long-term collagen formation.

Ellansé is CE-marked for soft tissue augmentation, indicated for facial volume loss, skin laxity and contouring.

It’s supplied ready to use, without the need for reconstitution and injections are typically subdermal using either needle or cannula.

Different versions of Ellansé offer different longevity profiles. Longevity for the ‘S’ product is 18 months, whilst ‘M’ offers 24 months.

The benefits of Ellansé lie in delivering both immediate and long-lasting results from one product, along with offering clinicians the flexibility of various product options.

Thanks to its strong clinical evidence base, Ellansé is also the first biostimulator included in the Global Evidence Matrix (GEM©). 

Should I introduce biostimulatory fillers to my aesthetic practice?

Biostimulators are a great addition to mono and multi-therapy approaches, and certainly have great ‘selling points’ from both patient and practitioner perspectives. 

However, the answer to this common question is something only you can answer. There should be a multi-factorial considerations when deciding whether you should take the plunge. For example:

• Am I clear on the ideal patient profile and contraindications for this treatment?
• How will this product complement or differ from the fillers and treatments I already offer?
• Am I confident that introducing this product aligns with my clinic’s values, patient demand and pricing structure?
• Do I have the necessary training and confidence in the injection techniques required? If not, do I know how to access this?
• Do I have protocols in place for managing complications or adverse outcomes?
• Can I explain the expected results, treatment timeline, and limitations to patients transparently?

What brand of biostimulator should I use?

When choosing any product for your practice, you should again be guided by asking yourself some clear, ethical questions.

• Am I satisfied there is sufficient high-quality clinical evidence supporting this product?
• Do I fully understand the rheology and mechanism of action of this biostimulator?
• Is the product CE-marked or MHRA-approved for the indications I intend to use it for?
• Can I explain the expected results, treatment timeline, and limitations to patients transparently?
• Is this product supported by reputable suppliers with robust educational resources?

After drawing your conclusions, you can further factor in other important aspects such as price and availability. Don’t discount comfort-related elements, too, both for your patient and in relation to how comfortable you find the syringe when injecting.

Evidence-based biostimulator guidance now included in GEM©

We’re pleased to announce that biostimulators are now recognised within the Global Evidence Matrix. This gives aesthetic practitioners a trusted, evidence-based framework for safe and effective use, tailored to their experience level.

The quick reference matrix details the following up-to-date information, for each biostimulator treatment. For example, listings include Zygomatic Arch with Cannula (Superficial), and Pre-Auricular Region with Cannula.

• Injection technique
• Needle or cannula and size details
• Injection depth
• Anatomical target (where you need the product to be deposited)
• Recommended total product volume.

Additional guidance explores entry points, aesthetic risks, post-treatment protocols and more. 

Ellansé is the first biostimulator included in GEM© and this is the product used in all biostimulator treatment demonstrations housed within our exclusive Case Study library. We hope this sets a precedent for other products in this category.

Watch Ellansé in action at the GEM© Clinic without a subscription

The GEM© by Harley Academy app is only available to subscribers and Harley Academy trainees taking aesthetics courses which include a free 12-month subscription. However, we have made some of our case study videos available via our YouTube account.

You can see Ellansé in action in Episode 5 of our Em case study for the GEM© Clinic, which is coming on 29th September. This features a live biostimulator demonstration by our Founder and CEO, Dr Tristan Mehta, as he treats his patient, Em.

Em initially came to him for a full face rejuvenation, however, he first had to assess the impact of her history of having fillers for the past 10 years. 

Following an in-depth consultation and ultrasound-guided facial assessment, the decision was taken to dissolve her fillers. Whilst necessary from a safety and aesthetic point of view, the volume loss after removing these filler remnants was distressing for Em. 

Dr. Tristan proceeded to re-treat her with elegant, evidence-based filler treatments over the next few months, all guided by GEM© principles. As her more defined structure and youthful contours emerged, the last step in her transformation was to address her skin. Dr Tristan used Ellansé to address Em’s skin laxity and improve the overall quality of her skin.

We can’t wait for you to see her results! Visit the HarleyAcademy YouTube channel to watch GEM© case studies. And for more information on Ellansé, contact Sinclair.

Please note, this article includes details relating to some of our commercial partners’ products. However, they are our partners for a reason. We believe in their products and the unbiased information presented is for educational purposes.

All information correct at time of publication