What is Microneedling?

Microneedling is a minimally invasive procedure that uses a device with multiple fine needles to puncture the epidermis and superficial dermis. These controlled micro-injuries trigger the skin's wound-healing response. It is studied mainly for acne scars and skin texture, and more recently, in small studies, for hair loss.

Mechanism of action

The procedure relies on the skin's natural ability to repair itself. Reviews describe how the micro-wounds set off an inflammatory response and the release of growth factors, which is thought to stimulate fibroblasts to make new collagen and to encourage new blood vessel formation (Singh & Yadav, 2016). How much of this happens, and how long it lasts, varies with needle depth, the device and the number of sessions.

Microneedling also makes the skin more permeable, so more of a topical product is absorbed. In a small pilot trial of 100 men with androgenetic alopecia, Dhurat et al. (2013) reported more hair regrowth when weekly microneedling was added to 5% minoxidil than with minoxidil alone.

Medical and aesthetic applications

In the US, the FDA has authorized some microneedling devices (as medical devices, not drugs) to improve the appearance of facial acne scars, facial wrinkles and abdominal scars in adults aged 22 or older. No microneedling device is FDA-authorized for hair loss. The FDA also states that microneedling devices are not approved for delivering cosmetics, topical medicines, vitamin solutions, drugs or blood products such as PRP into the skin.

Published studies have looked at microneedling for:

• Atrophic acne scars: several studies and reviews report improvement in scar appearance (Majid, 2009; Fabbrocini et al., 2014; Juhasz & Cohen, 2020).
• Acne scars in darker skin, combined with chemical peels: a study by Sharad (2011) reported improvement with microneedling plus glycolic acid peels.
• Androgenetic alopecia: a review by Ocampo-Garza et al. (2020) describes microneedling as a promising approach, but notes that the evidence comes mainly from small studies.

Safety and side effects

The FDA lists redness, bruising, bleeding and crusting as common side effects. Less common but more serious risks include changes in skin colour, infection and reactivation of cold sores (herpes). The FDA warns that re-using a needle cartridge is unsafe, even if it has been cleaned.

On a minoxidil page this matters: needling breaks the skin and increases how much minoxidil is absorbed, which may raise the chance of side effects such as irritation or effects elsewhere in the body. Ask a doctor about timing before applying minoxidil after needling. Reusing or sharing rollers can cause infection.

Commercial microneedling

Microneedling is offered in clinics and sold as home-use rollers and pens. Clinic devices usually reach deeper into the skin than home rollers. Home devices are often sold without the device authorization described above, and deeper needling at home raises the risk of bleeding, infection and scarring. Costs vary widely by country, device and clinic.

Number of sessions and duration of effects

Results depend on the problem being treated and the individual response. Study protocols for acne scars have typically used several sessions spaced weeks apart (Juhasz & Cohen, 2020). In the hair-loss pilot trial by Dhurat et al. (2013), results were assessed after 12 weeks of weekly sessions combined with minoxidil. Longer-term data are limited.

Conclusion

Microneedling has the most evidence, and FDA device authorization, for improving the appearance of acne scars and some other skin concerns. For hair loss it is promising but supported mainly by small studies (Ocampo-Garza et al., 2020), and no device is authorized for that use. Talk to a dermatologist before starting microneedling, especially if you use minoxidil or other topical treatments.

Dhurat, R., Sukesh, M. S., Avhad, G., Dandale, A., Pal, A., & Pund, P. (2013). A randomized evaluator blinded study of effect of microneedling in androgenetic alopecia: A pilot study. International Journal of Trichology, 5(1), 6-11. https://doi.org/10.4103/0974-7753.114700

Fabbrocini, G., et al. (2014). Percutaneous collagen induction: an effective and safe treatment for post-acne scarring in different skin phototypes. Journal of Dermatological Treatment, 25(2), 147-152. PMID 23216209.

Juhasz, M. L. W., & Cohen, J. L. (2020). Microneedling for the treatment of scars: An update for clinicians. Clinical, Cosmetic and Investigational Dermatology, 13, 997-1003. https://doi.org/10.2147/CCID.S232722

Majid, I. (2009). Microneedling therapy in atrophic facial scars: An objective assessment. Journal of Cutaneous and Aesthetic Surgery, 2(1), 26-30. https://doi.org/10.4103/0974-2077.53096

Ocampo-Garza, S. S., et al. (2020). Micro needling: A novel therapeutic approach for androgenetic alopecia, A Review of Literature. Dermatologic Therapy, 33(6), e14267. PMID 32882083.

Sharad, J. (2011). Combination of microneedling and glycolic acid peels for the treatment of acne scars in dark skin. Journal of Cosmetic Dermatology, 10(4), 317-323. https://doi.org/10.1111/j.1473-2165.2011.00579.x

Singh, A., & Yadav, S. (2016). Microneedling: Advances and widening horizons. Indian Dermatology Online Journal, 7(4), 244-254. https://doi.org/10.4103/2229-5178.185468

U.S. Food and Drug Administration. Microneedling Devices. https://www.fda.gov/medical-devices/aesthetic-cosmetic-devices/microneedling-devices