Non-Invasive Gluteal Augmentation and Rejuvenation

Clinical study of 29 cases — Combined protocol of high-intensity focused ultrasound, poly-L-lactic acid, and hyaluronic acid.

Pathophysiology of Gluteal Aging

Gluteal ptosis and volume loss represent a multifactorial disorder affecting distinct anatomical layers. The aging process involves a reduction in collagen and elastin production in the dermis, resulting in loss of skin firmness and elasticity. Concomitantly, atrophy of the subcutaneous adipose tissue and a decrease in gluteal muscle volume are observed (1).

Significant weight loss leads to a reduction in subcutaneous fat without proportional skin contraction, creating excess cutaneous tissue. Hormonal changes associated with menopause cause redistribution of adipose tissue and reduction in muscle mass. Lack of physical activity further contributes to gluteal muscle atrophy.

Given that gluteal dysmorphia involves multiple tissue levels, monotherapy often yields suboptimal outcomes with regard to patient satisfaction (1). This observation led to the development of combination protocols targeting different anatomical structures simultaneously.

Mechanisms of Action of the Three Technologies

High-Intensity Focused Ultrasound (HIFU). HIFU technology is based on the creation of focal thermal coagulation points in the dermis and the superficial musculoaponeurotic system (SMAS). Heating tissue to temperatures of 60–70°C causes denaturation of existing collagen and activates the process of neocollagenogenesis. The result is gradual skin tightening and lifting of deeper structures (4). Furthermore, when ultrasound is focused at deeper levels, remodeling of adipose tissue (lipo-remodeling) is achieved.

Poly-L-Lactic Acid (PLLA). PLLA is a biodegradable synthetic polymer that acts as a biostimulator. Following subcutaneous injection, PLLA microparticles induce a controlled inflammatory reaction that activates fibroblasts. This stimulation leads to neocollagenogenesis, predominantly of type I and III collagen (3). Results appear gradually and can last up to 24 months after completion of treatment. The material is degraded into lactic acid and eliminated through normal metabolic pathways.

Hyaluronic Acid (HA). High-molecular-weight cross-linked body hyaluronic acid fillers are characterized by high cohesivity and lifting capacity. When administered at deep subcutaneous or supramuscular level, they immediately restore volume and improve projection and symmetry of the gluteal area (2, 5). Results are predictable and reversible, with a duration of 12–18 months.

Synergistic Action. The combination of the three technologies allows simultaneous targeting of all tissue layers involved in gluteal aging: HIFU acts on the dermis and SMAS, PLLA on the subcutaneous tissue, and hyaluronic acid on the deep subcutaneous or supramuscular level. Immediate volume restoration by hyaluronic acid is combined with gradual tissue remodeling by HIFU and PLLA, balancing immediate volumization with progressive tissue remodeling.

Clinical Study

Study Population. The study included 29 patients (26 women, 3 men) with a mean age of 34 years. Inclusion criteria required the presence of mild to moderate gluteal volume loss and laxity. The study findings were presented at the IMCAS World Congress 2026 in Paris.

Treatment Protocol. In the 1^st session, HIFU was applied to the gluteal area using transducers at depths of 3.0–4.5 mm for the dermis and 6–9 mm for the SMAS, at an intensity of 0.7–2 J/mm². An average of 400–600 pulses per session were delivered, with a pulse duration of 2 seconds, in a grid pattern.

At week 2, PLLA (300–450 mg per side) was administered subcutaneously using a fan technique, followed by cross-linked high-molecular-weight hyaluronic acid at 20 mg/ml (30–40 ml per side) at the deep subcutaneous or supramuscular level. At week 8^th, PLLA administration was repeated with an optional supplementary dose of hyaluronic acid (10–20 ml).

Assessment. Standardized photographic documentation was performed at baseline and at 3 months. Projection, contour, firmness, and skin quality were evaluated.

Results

At the 3-month follow-up assessment, the majority of patients demonstrated significant improvement in projection, contour, and skin tone of the gluteal region. Firmness and elasticity were enhanced through the sequential application of HIFU and PLLA, while hyaluronic acid ensured immediate and symmetrical projection.

The patient satisfaction rate reached 89% at 3 months, a rate higher than that observed with individual therapeutic interventions. This finding suggests a synergistic action of the three technologies.

Safety. Adverse events were limited to transient edema and mild discomfort. No nodules, infections, or vascular complications were reported during the follow-up period.

Conclusions

The combination of HIFU, PLLA, and body hyaluronic acid fillers constitutes a safe, minimally invasive, and effective protocol for gluteal augmentation and rejuvenation. The multimodal approach addresses all tissue layers involved in gluteal aging and contour loss, providing immediate, natural, and long-lasting results. This approach is indicated for patients with mild to moderate gluteal laxity and volume loss seeking improvement without surgical intervention. For individualized assessment and determination of eligibility, scheduling a consultation with a specialized physician is recommended.

References

1. Gonzalez R. Etiology, definition, and classification of gluteal ptosis. Aesthetic Plast Surg. 2006;30(3):320-6.
2. Crabai P, et al. Nonsurgical Gluteal Volume Correction with Hyaluronic Acid: A Retrospective Study to Assess Long-term Safety and Efficacy. Plast Reconstr Surg Glob Open. 2024;12(5):e5792.
3. Jabbar A, et al. Poly-L-Lactic Acid for Gluteal Augmentation found to be Safe and Effective in Retrospective Clinical Review of 60 Patients. Dermatol Surg. 2020;46 Suppl 1:S46-S53.
4. Aslani A. High-Intensity Focused Ultrasound (HIFU) in Skin Tightening and Body Contouring. Aesthetic Surg J. 2025. 5. Assessment of Hyaluronic Acid Filler in Gluteal Augmentation and Contouring: A 1-Year Prospective Study. PubMed, accessed January 2026.