Bioremodelling agents such as collagen stimulators have a robust body of evidence that covers over a decade of research. Australia has been slow on the uptake of these injectables. The first dedicated biostimulatory injectable was only introduced in 2022.

Download these papers to understand more about biostimulatory injectables:

CAH skin tightening

Collagen stimulating injectables

HA biostimulators

PCL vs Polynucleotide

PLLA:PDLLA injectables

Polycaprolactone_collagen stimulator

Polynucleotide Rejuran

Dermal fillers provide volume, biostimulators are designed to stimulate collagen with minimal changes to volume. In most cases volume refers to correction of fat & bone atrophy, which occurs with age. Biostimulators are aimed at the upper layers of skin.

Exceptions apply, as there are dermal fillers that can have both volume replacement as well as biostimulatory actions, depending on the properties & dilution of the liquid. It’s complex.

Two main types of biostimulators, hyaluronic acid based & non-HA based.

• HA based: High and low molecular weight, non-cross linked. Profhilo
• Non-HA based: PLLA, PDLLA, PCL, Polynucleotide, CAH

Hyaluronic acid based biostimulators provide better tissue hydration with some aspects of collagen stimulation. Non-HA based compounds provide better collagen stimulation with minor to modest volume changes (based upon dilution). They do not hydrate skin as well as hyaluronic acid based injectables.

*Hence for patients in their 40s, the best combination includes both HA & non-HA based injectables.

The algorithm is complex as I work with different biostimulators & select the most suitable one for your skin type. I take into consideration your age, facial volume, skin quality, degree of background sun damage, dermal hydration levels, target areas as well as your expectations. A rule-

• Late 20s: Non-HA based biostimulators
• 30s-40s: HA based & non-HA based
• 40s-50s: HA based & non-HA volume replacing injectables
• 50s & beyond: HA based & non-HA volume replacing injectables

For a greater understanding of selection, read more.

There are two methods to deliver injectables, needle & cannula. Both methods take between 1-2 minutes to perform. The choice depends on the type & location of the injectable used.

Recovery depends on the injectable used & ranges from zero days recovery to 48 hours.

• PLLA or calcium hydroxyapatite biostimulator: no recovery
• Hyaluronic acid biostimulator: 6-hour recovery
• PCL biostimulator: 1–2-day recovery
• Polynucleotide: 48-hour recovery

Results can be seen within one to two weeks in patients with dehydrated skin as hyaluronic acid biostimulators (Prohilo) instantly rehydrate the dermis.

Skin firming & tightening however, may take up to 6 months as new collagen requires time to regenerate. This applies to biostimulators such as Sculptra, Radiesse, Gouri & Rejuran. 

*The primary aim of bio remodelling agents is to prevent age related collagen depletion. By definition, mitigation is a result you don’t see.

2-4 depending on your level of collagen loss & dermal hydration. As a guide-

30s to mid 40s: 2 sessions

40s to mid 50s: 3 sessions

50s to 60s & beyond: 3-4 sessions

The exact number of sessions depends on two main factors- the degree of collagen loss & your ability to generate new collagen.

It depends on your age, expectations & degree of skin aging. As a guide, after the first year-

• HA biostimulators: 1-2 times annually
• Non-HA biostimulators: 1-2 times per year

The older you get, the more frequent the injectables as you will be playing ‘catch-up’, namely replacing collagen depletion with age in addition to mitigating collagen loss with time.

Ignore marketing from clinics & companies. Here is the truth- the primary aim is to reduce age related degradation of collagen. With careful selection of injectable products, this is achievable in most patients (>95%).

As for clinically observable skin tightening, this is seen in 30-70% of patients. The results are dependent upon –

• Correct selection of product
• Dilution of product
• Number of sessions
• Background sun damage
• Age, race & skin condition
• Your genetic response to injectables (that’s the biggest variable)

Summarised: mitigation is something you don’t see, with accurate clinical acumen & selection, most, but not all patients will have clinically evident skin tightening.

A good starting age is in the early stages of collagen loss, namely in the early 30s. Remember, collagen depletion occurs at 1-1.5% per year, starting in the early 20s.

The earlier you start, the less the number of injectable sessions.

During the first few years of menopause, there is an accelerated decline in collagen- 30% over a span of only 5 years. This, coupled with bone loss & changes in the deep & superficial fat pads leads to accelerated aging in the early 40s to 50s.

Rhetorical question. The same applies to facial aging. The first step is to prevent further degradation of collagen, elastin & hyaluronic acid with biostimulatory injectables (ideally augmented with low-level biostimulants). Invest in prevention, then move to correction. 

*Think of aging as the ‘termites of collagen degradation’, by imitating timely treatments one can slow down the decay of time.

• HA based high-low biostim: $950 by Davin Lim, $850 by nurses
• CAH biostim: $1290 by Davin Lim, $990 by nurses
• PLLA biostim: $1290 by Davin Lim, $990 by nurses
• PCL biostim: $1290 by Davin Lim, $990 by nurses
• Polynucleotide: $770 by Davin Lim, $720 by nurses

*I use similar biostimulators in Sydney. For appointments, please contact Tracee at Clinic DVP. Book with Kate or myself.

The buzz word is Profhilo– the first ‘marketed’ biostimulator/ bioremodelling agent introduced into the Australian market in 2022. IMO, this injectable is overhyped, but necessary (if you are over the age of 40). Why overhyped? Because it is a very weak stimulator of fibroblast (cells that produce collagen). Why is it necessary? Because there is an age related reduction of hyaluronic acid that predisposes to ‘dermal dehydration’ (something HA serums cannot fix).

Profhilo summarized-

• 2-3 sessions spaced 4 to 8 weeks apart
• Minimal downtime of 6-12 hours
• Best used to hydrate the dermal layers of skin
• Can be used on the face, neck & decolletage areas
• I encourage this injectable in just about everyone over 40 years of age
• Best employed with more potent biostimulators that increase collagen production

Polynucleotides are new for Australia. Rejuran is the trade name & is TGA approved for 2023. This compound is derived from DNA extracted from salmon by products (gonads-sperm). It works superficially & stimulates collagen production in the upper layers of skin. This injectable is less powerful than established collagen stimulators such as PLLA, CAH & PCL. It is best used as a preventative, rather than a potent collagen stimulator.

Rejuran summarized

• 3-4 treatment sessions
• Downtime of 48 hours (blebs)
• Requires numbing gel application prior to injection
• Suitable for all skin types
• Best used around the eyes to treat fine lines & wrinkles
• Provides minimal to no volume
• Employed as mitigation over correction of wrinkles

This is probably the best biostimulator to enter the Australian market as of 2023. It has a long safety record in Europe & Asia. Gouri provides maximal stimulation of collagen in the lower dermis & requires 3 sessions for optimal results. It can be used on the face & neck area. The downside is that inflammatory responses are more common with this injectable compared to others. This will be TGA approved by 2024.

Gouri Summarised

• 3 sessions, spaced 4-10 weeks apart
• Downtime variable, 1-3 days
• Injections mixed with numbing agent
• Suitable for all skin types
• Takes 3-6 months for optimal results
• Provides little volume, hence ideal for mature lower face

PLLA is the oldest biostimulatory injectable in Australia with a safety record of two decades. It is also used as a dermal filler as it provides volume in key areas such as the mid-face & temples.

Sculptra summarized

• 3-6 sessions spaced 6-10 weeks apart
• No downtime
• Sculptra can provide improvements in skin quality, but results are not great
• Provides volume in addition to collagen stimulation
• Takes 3-6 months for optimal results
• Best used in the mature age group or volume depleted younger age group

Also known as Radiesse, this powerful remodelling agent is flexible in its delivery. I use this to remodel atrophic acne scars, however as a dermal filler, it is excellent around the jawline area. 

PDLLA is an injectable in Australia that has been applied for TGA approval in 2023. It is also used as a dermal filler as it provides volume in key areas such as the mid-face & temples. The volume effects are faster than PLLA – Sculptra as the particles are more porous (larger surface area).

AestheFill summarized

• 2-3 sessions spaced 6-10 weeks apart
• Possibly more powerful than PLLA- Sculptra
• Is more porous cf. PLLA, hence has a faster ‘immediate’ action
• Provides volume in addition to collagen stimulation
• Takes 3-6 months for optimal results
• Best used in the mature age group or volume depleted younger age group

You just age as per your genetic timeline. There is no evidence that stopping injectables will accelerate aging.

Skin care does not build collagen to a degree of skin firming, nor will it markedly mitigate- reverse collagen. Skin care however is important to improve skin quality, namely provide even skin texture, reduced pigmentation as well as minimize pore sizing & fine lines. A simple skin care routine to reduce UV induced damage to your skin goes like this-

• AM: Antioxidants (Vitamin C, E), SPF
• PM: Retinol

Skin care forms the cornerstone of preventing UV induced photodamage, however in the scheme of biostimulation potential, it ranks as (almost) negligible.

For more on skin care, please book an appointment with our dermal therapists or nurses as to product recommendations.

LEDs are useful treatments to consider, however they are overmarketed & over hyped. LED therapy is most useful for: treatment of acne & recovery following procedures such as lasers or radiofrequency micro needling. LEDs provide very little in the way of collagen stimulation, as compared to biostimulatory injectables.

*We offer these treatments at Cutis Dermatology, Brisbane & Van Park’s Clinic, Sydney. If you would like to consider LED, microneedling & or PRP, book an appointment with our therapists/nurses.

Fortunately, side effects are rare following biostimulator injections. The injectable of choice with the lowest side effect is hyaluronic acid based biostimulators, or Profhilo. 

Non-HA based injectables have a slightly higher rate of side effects including-

• Nodules/lumps & bumps
• Persistent redness
• Post inflammatory pigmentation
• Swelling of approximately 3-5 days
• Allergies

Microneedling is a low level biostimulatory procedure that can help improve skin quality & texture. In the scheme of things, it produces marginal effects as compared to lasers & injectables. Provided you are sensible with things, you can perform this procedure at home using a 0.25 mm stamper, roller, or pen.

RFM or radiofrequency microneedling is classed as high level biostimulation, meaning treatments should NOT be performed frequently. Refer to the term conditioned reflex below.

Devices such as Morpheus8, Genius RF & Potenza provide a significant amount of heat over a short period of time. Much like lasers, they can be performed at intervals of 12 to 48 months apart (after a series of sessions).

Your choices are limited to low level biostimulatory devices such as radiofrequency (NuEra or Pelleve), or high level biostimulatory devices such as lasers, chemical peels, HIFU, cog threads (different from mono threads) & other energy devices. Here is a short take on these treatments-

• Lasers & chemical peels are great for skin quality, collagen stimulation is limited to the upper layers of skin. The best laser is CO2, but the downtime is long- up to 2 weeks.

• HIFU: best for fat breakdown of key areas around the jowls & jawline. Can be effective in some patients (no sun damage, thicker dermal layer, more subcutaneous fat).

• Threads: Monofilament PDO threads are a waste of time, cog threads are better, filler threads & anchoring threads are best. They work to ‘lift’ or more accurately reposition sagging skin. Filler thread can stimulate collagen production, however injectables are more predictable, less painful & have a faster recovery.

• RF & RF microneedling: are good treatments for ‘high-heat’, they can help reduce laxity in some patients & provide variable amounts of collagen production. Devices such as Morpheus8, Genius RFM, Infini, Instensif, Secret RFM & Potenza are best combined with injectables.

For more information on the concept of conditioned responses, refer to the section below.

Collagen stimulation should be paced. If you keep hitting your fibroblasts with high level biostimulation, chances are you will run out of options within a short period of time. This is termed conditioned reflex. Apply high level stimulation at intervals when required, maintained with low-level biostimulation.

High level biostimulation refers to ablative lasers (like CO2), high intensity RF microneedling (Morpheus8, Profound RF, Potenza, Infini, Genius RFM), Face Tite RF, HIFU & Softwave.

Low level biostimulation describes biostimulatory injectables, and multipass RF devices, skin care & LEDs (extremely low level biostimulation) & home use devices. I am a believer of employing as many low level biostimulatory avenues as possible- if you can afford it.

Hyaluronic acid serums are awesome as moisturizers & humectants. They can be purchased online, at The Formulated or in-clinic. HAs trap water & provide hydration to the upper layers of skin.

HA injectables (as the name suggests), provide deep dermal hydration, which cannot be achieved with skin care.

Asia & Europe are well ahead of Australia when it comes to the use of dermal fillers & collagen stimulating injectables, thanks in part to our strict TGA assessment. Australia is between 8 to 3 years behind Europe & Asia respectively, however it is not all bad news, as other countries have largely ironed out the potential problems & limitations before injectables hit our shores.

For example, we know how to modulate the inflammatory responses of PCL injectables, as well as the limitations of hyped injectables like Profhilo.