Letybo (letibotulinumtoxinA) is a newer botulinum toxin type A formulation developed by Hugel, a South Korean biopharmaceutical company. It joins a growing list of botulinum neurotoxin serotype A (BoNT-A) products used in aesthetic and therapeutic medicine. The primary competitors of Letybo include onabotulinumtoxinA (Botox®), abobotulinumtoxinA (Dysport®), incobotulinumtoxinA (Xeomin®), and prabotulinumtoxinA (Jeuveau®). The following is a comparative analysis based on current scientific literature and available clinical data:

1. Molecular Composition & Formulation

Implication: The presence of complexing proteins may affect immunogenicity and diffusion, although clinical relevance is still debated. Letybo is structurally similar to Botox, both being 900 kDa complexes.

2. Potency and Dose Equivalence

Letybo’s units are not bioequivalent to other BoNT-As on a 1:1 basis, but early studies suggest its clinical potency is comparable to Botox when administered at equal unit doses.

3. Clinical Efficacy

Most studies on Letybo focus on glabellar line treatment, with Phase III trials conducted in Asian and, more recently, European populations.

• Efficacy Onset: Similar to Botox (2–3 days).
• Peak Effect: 1–2 weeks post-injection.
• Duration: ~12–16 weeks (comparable to Botox and Jeuveau).

Head-to-head data comparing Letybo with Botox or other agents in diverse populations (especially non-Asian) are currently limited. A Korean Phase III study (Lee et al., Dermatol Ther, 2021) found non-inferiority to Botox for glabellar lines at week 4.

4. Safety and Adverse Event Profile

Letybo has shown a favorable safety profile consistent with other BoNT-As in trials. No unique adverse effects have been reported.

5. Immunogenicity

Theoretically, toxins without complexing proteins (e.g., Xeomin) might have lower antigenicity, but clinically relevant immunogenicity remains low across all BoNT-As when used in aesthetic doses. No long-term data yet confirm differences in neutralizing antibody development for Letybo.

6. Regulatory & Market Access

• Letybo: Approved in South Korea, China, Canada, and EU (2022). FDA approved (2024) in the U.S.
• Botox/Xeomin/Dysport/Jeuveau: All approved in U.S. and globally widespread.

7. Cost and Economic Consideration

Letybo has been marketed as a cost-effective alternative in regions like South Korea and China. Its competitive pricing may drive adoption, particularly in aesthetic markets sensitive to cost margins.

Conclusion

Letybo is a viable alternative to existing BoNT-A products with comparable efficacy, safety, and pharmacologic properties, particularly similar to Botox in terms of molecular weight and clinical onset/duration. However, due to its limited longitudinal data and fewer global head-to-head trials, particularly in diverse patient populations, broader clinical acceptance (especially in Western markets) may depend on further robust, comparative trials and real-world experience.

The optimal choice of facial chemical exfoliants depends on individual skin type, concerns, and tolerance. Chemical exfoliants fall into three primary categories: alpha-hydroxy acids (AHAs), beta-hydroxy acids (BHAs), and polyhydroxy acids (PHAs). Each group possesses distinct physicochemical properties and dermatological indications. Below is an evidence-based overview of the most efficacious and commonly recommended agents.

1. Alpha-Hydroxy Acids (AHAs)

AHAs are water-soluble and primarily act on the stratum corneum by weakening the cohesion of corneocytes. Ideal for dry, photodamaged, or dull skin.

Common AHAs:

• Glycolic Acid
  • Molecular weight: 76 Da (smallest, most penetrative AHA)
  • Effects: Enhances collagen synthesis, reduces hyperpigmentation, improves texture
  • Evidence: Clinical trials show significant improvement in photoaged skin with concentrations of 8–20% (Stiller et al., 1996)
• Lactic Acid
  • Molecular weight: 90 Da (larger, gentler than glycolic)
  • Effects: Hydrates while exfoliating, suitable for sensitive or rosacea-prone skin
• Mandelic Acid
  • Molecular weight: 152 Da (aromatic AHA with slow penetration)
  • Effects: Antibacterial properties, well-tolerated in acne and sensitive skin
  • Evidence: Demonstrated efficacy in treating inflammatory acne and melasma (Fabbrocini et al., 2009)

2. Beta-Hydroxy Acids (BHAs)

BHAs are lipid-soluble, allowing them to penetrate sebaceous follicles, making them particularly effective for acne-prone or oily skin.

Primary BHA:

• Salicylic Acid
  • Mechanism: Keratolytic, comedolytic, and anti-inflammatory
  • Concentration range: 0.5–2% in OTC products
  • Evidence: Reduces comedones and inflammatory acne lesions (Kligman & Mills, 1972)

3. Polyhydroxy Acids (PHAs)

PHAs are larger molecules that exfoliate more superficially, with humectant properties and antioxidant effects. Suitable for very sensitive or compromised skin (e.g., eczema, post-procedural).

Common PHAs:

• Gluconolactone
• Lactobionic Acid

Evidence:

• PHAs demonstrate comparable efficacy to AHAs with less irritation and added barrier support (Roure et al., 2009)

Top Formulations and Brands (as of 2024)

Selection Guidelines by Skin Type

Safety and Usage Considerations

• Frequency: 2–3 times/week for most; daily use requires careful barrier protection.
• Sun protection is mandatory, as exfoliation increases photosensitivity.
• Avoid combining with retinoids or ascorbic acid without dermatological oversight, due to increased irritation risk.

In recent years, GLP-1 receptor agonists like Ozempic® (semaglutide) and Mounjaro® (tirzepatide) have revolutionized the landscape of medical weight loss. Originally developed to manage type 2 diabetes, these medications are now widely prescribed for obesity and cosmetic weight reduction. However, with rapid and often dramatic weight loss, a new aesthetic concern has emerged—commonly known as “Ozempic face” or “Mounjaro face.”

As facial plastic surgeons, we’re seeing a significant uptick in consultations related to this phenomenon, and the demand for restorative facial procedures is rising accordingly.

What Is “Ozempic Face” or “Mounjaro Face”?

The term refers to the volume loss and skin laxity that can result from rapid weight loss, particularly in the midface, temples, and jawline. While GLP-1 medications are medically effective for systemic health, the face is often one of the first areas to show signs of catabolic changes.

Common features include:

• Sunken cheeks and temples
• Hollowed eyes and under-eye bags
• Sagging jowls and nasolabial folds
• Accelerated appearance of aging

This is especially pronounced in individuals over 35, when collagen and facial fat compartments are already naturally declining.

Why Does This Happen?

GLP-1 medications like Ozempic and Mounjaro work by:

• Suppressing appetite
• Slowing gastric emptying
• Regulating insulin and blood sugar

While the systemic benefits are profound, rapid fat loss in facial areas with thin skin and limited structural support often leads to:

• Loss of deep fat pads (malar, buccal, and periorbital)
• Volume deflation without time for skin redraping
• Laxity exacerbated by aging or sun damage

This can result in a gaunt or aged appearance, despite overall improvements in body composition.

Facial Plastic Surgery & Aesthetic Solutions for Ozempic/Mounjaro Face

Fortunately, there are several effective surgical and non-surgical treatments to restore facial harmony after GLP-1-related weight loss.

1. Facial Fat Grafting

One of the most natural and long-lasting solutions, autologous fat transfer replenishes lost volume using the patient’s own fat harvested from other areas. It’s ideal for:

• Midface and cheek augmentation
• Temple hollowing
• Nasolabial folds

2. Mini Facelift or Deep Plane Facelift

For patients experiencing laxity and jowling, especially over age 40, surgical lifting procedures such as a mini facelift or deep plane facelift can re-suspend tissues and tighten skin for a more youthful contour.

3. Dermal Fillers

Hyaluronic acid and collagen-stimulating fillers offer non-surgical volume restoration and contour refinement, particularly for younger patients or those early in their weight loss journey.

4. Skin Tightening Treatments

Devices like Ultherapy®, radiofrequency microneedling, and laser skin tightening can help stimulate collagen and improve mild to moderate laxity.

Mounjaro vs. Ozempic: Are Facial Effects Different?

While both medications act on the GLP-1 pathway, Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist and may induce more significant weight loss than Ozempic. This can translate to more pronounced facial volume loss, especially in leaner individuals.

That said, individual responses vary based on:

• Duration of use
• Dosage escalation
• Baseline facial fat distribution
• Age and skin elasticity

Should You Start GLP-1 Therapy If You’re Concerned About Your Face?

GLP-1 medications like Ozempic and Mounjaro are powerful tools for metabolic and cardiovascular health, and their aesthetic impact can be proactively managed. If you’re considering or currently using these medications and are concerned about facial changes, a consultation with a board-certified facial plastic surgeon can help you develop a tailored plan for volume preservation and facial support.

Conclusion

The rise of Ozempic face and Mounjaro face highlights an important interplay between systemic health and facial aesthetics. As weight loss medications reshape the future of obesity management, facial plastic surgery continues to evolve in response, offering solutions that restore balance, youthfulness, and confidence.

Double eyelid surgery, also referred to as Asian eyelid surgery and Asian blepharoplasty, was first described by a Japanese surgeon by the name of Dr. Kotaro Mikamo in an 1896 publication entitled “Plastic operation of the eyelid” in J Chugaii Jishimpo, during the Meiji era. In his publication he describes the prevalent eyelid appearance in the Japanese population to be the “double” eyelid, which occurred by his account in approximately 80% of the population, and sought to emulate and recreate this aesthetic for the minority who did not possess it at birth. He sought to define and enhance a Japanese aesthetic to create natural looking eyes, eyes that look like the patient could have been born that way. One of his before and after photos includes a patient with a natural supratarsal crease (upper eyelid crease) on her left eye, which he successfully recreated with surgery on the right eye.

More than half a century later, an American by the name of Dr. Ralph Millard began his rudimentary attempts at double eyelid surgery while stationed in Korea during the Korean War (1950-53), operating primarily on Korean war brides married to American servicemen, with middling results. While he often did create an upper eyelid crease, judged by the lens of today’s cosmetic surgery standards, the aesthetic would have likely made him the center of a bit of derision. Nevertheless, this marked the seminal moment for Korean surgeons to begin developing their techniques and refining their aesthetics. In 1961, the first university department of plastic surgery in Korea was developed at Yonsei University, and in 1974, the Supreme Court in Korea approved plastic surgery for cosmetic purposes as medical practice.

Fast forward to today, and Korea has enjoyed a reputation for decades of being a world leader in plastic surgery and especially cosmetic plastic surgery. K beauty has come to symbolize the blending of leading technology with the most advanced cosmetic treatments. Part of this rapid rise in plastic surgery mirrors the rapid rise of Korea’s economy, technology and infrastructure coming from the ruins of the Korean war. The combination of work ethic, creativity and innovation have helped to push forward development and progress, with increasingly refined results.

In this globalized climate contemporary plastic surgeons occupy, the sharing of knowledge, techniques and ideas through publications, meetings, and instantaneously through broadband connections, allows us all to push each other to even greater heights.