Microtoxin or microbotox is a novel approach in aesthetics where microdosed botulinum toxin is placed into the dermis. Unlike traditional neuromodulators that target skeletal muscle, microtoxin acts within the dermis, impacting sebaceous and eccrine glands, arrector pili contraction, fibroblast signaling, and neurovascular pathways. The result is enhanced skin quality without impaired facial muscle movement.
In a poster presented at ODAC, researchers shared the results of a retrospective chart review on microtoxin for skin quality. I interviewed poster author Carolyn Duong, BS, with the Kansas City University College of Osteopathic Medicine.
Neurotoxins have been in cosmetic use for more than twenty years. How did the idea of microdosing come about?
Microdosing neuromodulators originated from early clinical observations that patients treated with standard intramuscular botulinum toxin for dynamic lines often experienced improvements in overall skin quality in the treated area, such as the forehead. Clinicians noted smoother texture, reduced sebum, and increased luminosity, and patients began asking for similar effects in other facial regions. Many of these other areas, such as the perioral, nasal, and periocular zones, are high‑risk for traditional intramuscular injections because the resulting muscle paralysis would cause uneven facial expression and undesirable functional changes. To address patient demand for skin improvement without significantly affecting muscle movement, practitioners developed microtoxin techniques that deliver very small, diluted doses to the skin across the entire face, aiming to enhance overall skin quality while preserving natural expression.
What is the microtoxin technique, and how does it differ from traditional neuromodulator injections?
The microtoxin technique involves injecting highly diluted botulinum toxin (~20 U/mL, 100 U reconstituted in 5 mL saline) in small volumes (~0.05 mL) into the dermis or superficial subdermal plane using multiple closely spaced points (~1 cm between injection points). Traditional neuromodulator injections target deeper muscle layers at specific anatomic sites to reduce muscle contraction and soften dynamic wrinkles. In contrast, microtoxin is distributed across broader areas of the skin where superficial structures, such as sebaceous glands, tiny muscle fibers, and neurovascular networks, can be influenced. Due to this superficial placement and dilution, microtoxin generally does not produce significant muscle paralysis but instead modulates cutaneous factors that contribute to skin texture, oiliness, pore appearance, and redness. The goal is to provide a more diffuse improvement in skin quality rather than the focal muscle weakening achieved with conventional neuromodulator dosing.
What concerns does microdosing address that traditional neurotoxins cannot?
Microdosing was developed to address aesthetic concerns that are not reliably treated with traditional intramuscular neuromodulator injections, such as enlarged pores, excess sebum production, diffuse erythema, uneven texture, and lack of skin luminosity. Standard neuromodulator dosing in delicate areas, such as around the mouth or eyes, carries a higher risk of unwanted muscle weakness and functional changes. Microtoxin allows clinicians to treat these regions to enhance overall skin appearance with a lower risk of disrupting muscle activity. By delivering superficial, diluted injections across the face, practitioners can broaden the scope of botulinum toxin use to include skin quality domains that previously could not be directly addressed with conventional techniques.
You conducted a retrospective chart review. What did you discover about microtoxin’s efficacy for texture, erythema, and scar refinement?
In our retrospective chart review, we observed meaningful improvements in multiple aspects of skin quality following microtoxin treatment. Many patients showed smoother skin texture and reduced pore visibility, particularly those with oily skin and enlarged pores. A notable number of patients with facial erythema, especially those with erythematotelangiectatic rosacea, experienced reductions in redness and flushing, suggesting that superficial neuromodulation may influence vascular and inflammatory pathways. For scar refinement, the most consistent improvements were seen in shallow or tension‑related scars, such as early atrophic and rolling scars, where modulation of superficial muscle pull appears to improve skin smoothness. These clinical observations support the therapeutic potential of microtoxin beyond traditional wrinkle reduction and align with reported data showing objective improvements in skin texture and pore size.
In which conditions were microtoxin not effective or not as effective as other modalities?
Microtoxin was less effective for conditions that require deeper structural correction, volume restoration, or significant lifting. Patients with deep static wrinkles, marked skin laxity, or advanced facial sagging generally achieved better outcomes with fillers, energy‑based devices, or surgical approaches rather than microtoxin alone. Deep ice‑pick scars and hypertrophic or keloid scars did not respond significantly to microtoxin when used in isolation. Among rosacea subtypes, microtoxin reduced erythema and flushing, but inflammatory papulopustular rosacea required traditional medical therapies for meaningful control. These limitations underscore the importance of appropriate patient selection and, when necessary, combining microtoxin with other modalities to address complex or deep‑seated aesthetic concerns.
What should dermatology clinicians take away from your study on the use of microtoxin for skin rejuvenation?
Dermatology clinicians should view microtoxin as a complementary tool in the aesthetic toolbox for improving skin quality. When used with proper patient selection and technique, microtoxin can address texture irregularities, enlarged pores, excessive sebum, mild erythema, and shallow scars with minimal impact on muscle function and natural expression. Clear communication with patients about realistic outcomes and limitations remains essential, as microtoxin does not replace fillers, lasers, or surgical interventions for structural or volume‑related concerns. Clinicians should also be aware of the variability in dosing and technique reported in the literature and strive to refine their protocols. Continued research and standardization will help further define optimal microtoxin use and may expand its role in comprehensive skin rejuvenation.
Additional authors of the poster include:
Karen Vo, DO, Desert Regional Medical Center, Palm Springs, CA
Lynn Fadel, BS, California Health Sciences University College of Osteopathic Medicine
Natalie Govea, MS, Burrell College of Osteopathic Medicine
Lauren DeLamielleure, MS, Florida International University Herbert Wertheim College of Medicine
Kelly Frasier, DO, MS, Department of Dermatology, Northwell Health
Alina G. Bridges, DO, FAAD, Department of Dermatology, Northwell Health