Radiofrequency (RF) microneedling has become a popular treatment in aesthetic clinics with good reason: it is safe and effective, with minimal downtime in all skin types. The treatment can be used as a standalone or in combination with a variety of treatments.
What is radiofrequency microneedling?
RF microneedling uses sharp needles to penetrate the skin and pass non-ionising electromagnetic radiation through the dermis. There are two types of needles: insulated and non-insulated. Non-insulated microneedles emit radiofrequency energy over their entire surface area, allowing both the upper and lower layers of the skin to be heated at once. Insulated microneedles have a layer of insulation around them, which allows the heat to only be emitted from the end tip, heating just the lower layers of the dermis and sparing the epidermis.
Non-insulated needles tend to cause more downtime and are more painful but are thought to provide better results. The author could not find any split-face studies comparing the two types. There are also semi-insulated needle devices.
How it works
The fractional thermal injury induced by RF microneedling produces a profound wound-healing process. This leads to an inflammatory response and increased production of collagen, elastin and hyaluronic acid, as well as eventual dermal remodelling (Lim et al, 2013). It also causes the proliferation and migration of keratinocytes (Lolis and Goldberg, 2012).
The advantage of using RF microneedling over lasers is that the energy is not affected by tissue diffraction or chromophore and can be used in any skin type. The RF energy is much more controllable than lasers (Franco et al, 2010).
Effectiveness of radiofrequency microneedling
A systematic review of RF microneedling, both alone and in combination with other treatments, showed noteworthy results in treating the following areas: atrophic acne scars, skin rejuvenation, hypertrophic scars, keloids, striae distensae, androgenetic alopecia, melasma and acne vulgaris (Ramaut et al, 2018). The review concluded that RF microneedling is safe and effective. However, there were some methodological shortcomings, and it was suggested that more research was needed to improve the evidence base.
Another systematic review (Hou et al, 2017) came to similar conclusions. Furthermore, Cohen and Elbuluk (2016) concluded that RF microneedling is an effective and safe treatment for a variety of dermatological conditions in skin of colour.
Side effects and issues
Lee et al (2014) concluded that pain and temporary erythema were the main side effects of treatment with RF microneedling. Some vesiculation can occur, but this is thought to be due to poor technique.
Post-inflammatory hyperpigmentation improved within 4 weeks. However, anecdotally, there can be significant pain with RF microneedling devices, and this can limit treatment effectiveness.
Applications of radiofrequency microneedling
Periorbital rejuvenation
Yogya et al (2022) found RF microneedling, both alone and when used to introduce polynucleotides transdermally, to be effective in treating periorbital wrinkles in Asian patients. Another small study (Wu et al, 2022) found significant improvements in mixed type infraorbital dark circles using an RF microneedling device. Periorbital wrinkling in particular was significantly reduced.
» There is some worry that using non-insulated needles in pigmented skin (such as Fitzpatrick type III or IV) might exacerbate the issues. However, Gulfan et al (2022) concluded that it is safe in these skin types, improved skin texture and was a possible adjunctive treatment of melasma «
Generalised facial rejuvenation
There are several studies that confirm that wrinkles, skin laxity and texture were improved with RF microneedling, with tolerable side effects and downtime (Seo et al, 2013; Alessa and Bloom, 2020).
Tan et al (2021) reviewed the literature and concluded that, ‘Radiofrequency microneedling is an effective intervention that can be used repeatedly and safely in combination with other treatment modalities and in individuals with darker skin phototypes. RF microneedling-induced dermal remodelling and neocollagenesis are slow and progressive but continue to improve, even 6 months after treatment’.
Acne scarring
RF microneedling is effective in reducing and treating acne scarring.
In their systematic review, Simmons et al (2014) found that there was a 25–75% improvement in atrophic acne scars with three to four sessions of treatment with RF microneedling. Chae et al (2015) compared Er:glass fractional laser and RF microneedling in the treatment of atrophic acne scars with similarly good results. Needle depth is usually around 1.5–2mm for scarring.
Keloid and hypertrophic scars
Although there is promising evidence that RF microneedling is effective in treating keloid and hypertrophic scars 12 months after treatment, the exact parameters are yet to be clarified according to systematic literature review (Iosifidis and Goutos, 2019).
Striae distensae (stretch marks)
Some studies have been conducted that show the effectiveness of RF microneedling in treating stretch marks. Khater et al (2016) found it more effective than fractional CO2 laser. Later, Lokhande and Mysore's (2019) review concluded that RF microneedling and fractional CO2 are first-line treatments for stretch marks. However, they acknowledged that a combination of a variety of treatments would be optimal.
Melasma
There is some worry that using non-insulated needles in pigmented skin (such as Fitzpatrick type III or IV) might exacerbate the issues. However, Gulfan et al (2022) concluded that it is safe in these skin types, improved skin texture and was a possible adjunctive treatment of melasma. Jung et al (2019) concluded it was also a useful adjunct to laser toning. The use of RF microneedling with topical agents appears to be helpful.
Conclusion
There is good evidence that RF microneedling is effective in treating a variety of dermatological conditions. However, there remains no consensus on the correct protocols for treatment.
Many devices in the marketplace supply protocols, but, anecdotally, practitioners often ignore these parameters and develop their own methods. Therefore, it is difficult to know how to optimise treatments.
The real positive is that RF microneedling using non-insulated needles is safe for patients with darker skin types.