Thread lifting technologies have emerged as a minimally invasive yet biologically active approach for aesthetic correction. Originally developed for mechanical tissue suspension, modern thread systems now serve as multifunctional platforms that integrate structural support with regenerative signaling. By leveraging advances in polymer chemistry, bioresorbable scaffolds, and hyaluronic acid (HA) delivery, next-generation threads are designed to modulate dermal remodeling while providing immediate lifting effects.

Modern thread lifting techniques for correcting age-related facial changes have evolved through continuous advancements in thread composition and clinical protocols. Recent progress in tissue engineering, regenerative medicine, and biocompatible materials has provided a robust scientific foundation for integrating innovative thread technologies into dermatological practice, thereby broadening the therapeutic options in aesthetic medicine.

Modern lifting threads are systematically classified on the basis of a number of parameters that determine their biomedical and operational properties. The key classification criteria include the chemical nature and biodegradation characteristics of the material, size-and-shape parameters (including diameter), mechanical strength, and microstructure and surface topography, which influence tissue integration and the degree of fibrous response. The functional features of the threads also play an important role in the selection of a specific technique and in determining the expected clinical outcomes when performing thread lifting procedures.

The structural component of thread implants plays a critical role in modulating the biological responses of recipient tissues, determining the degree of biocompatibility, the characteristics of the inflammatory reaction, and the extent of new collagen and blood vessel development (neocollagenesis and angiogenesis). Furthermore, the structural features of a material largely determine its susceptibility to microbial adhesion and subsequent bacterial colonisation.

Lifting threads are classified on the basis of their surface morphology and physical properties:

Monofilament (Mono) sutures are smooth-surfaced threads designed to minimize tissue trauma during insertion. They are most often used for reinforcement. These threads are quite thin and are therefore ideal for working with delicate areas, such as thin skin and regions with minimal subcutaneous fat. Their primary function is to stimulate the formation of a collagen framework in the dermis and to improve skin quality by inducing microtrauma in the tissues.

Spring/Twin threads are a type of thread implant characterised by pronounced elastomeric properties, including “shape memory” capabilities. After implantation into tissues, they tend to return to their original helical configuration, providing a pronounced mechanical lifting effect through the distribution of tension vectors within the three-dimensional structure of the dermis and hypodermis. This design feature helps not only in repositioning soft tissues but also in effectively correcting local asymmetry, shaping desired contours, and restoring lost volume in areas affected by age-related involution.

Barbed sutures, featuring barbed structures along the entire length of the thread, provide mechanical fixation within the SMAS layer (a fibrous layer beneath the skin and fat of the face), contributing to the formation of a stable tension vector and a prolonged lifting effect. The morphology of the barbs varies depending on the clinical task and the intended area of correction. Currently, designs with unidirectional, bidirectional, or multidirectional barb orientation are used, depending on the clinical task and the intended area of correction. These modifications optimise the tension distribution, achieve uniform tissue traction along the implantation line, and minimize the risk of displacement. Thus, barbed sutures combine a mechanical lifting effect with the biostimulating potential associated with the tissue response to microtrauma, making them a highly effective modality for the aesthetic correction of age-related changes.

When implanted in soft tissues, a lifting thread is generally capable of inducing three distinct rejuvenating effects: lifting, reinforcing, and biostimulating. Clinical observations indicate that each specific type of thread tends to predominantly exhibit one of these effects, whereas the other two types are present to a lesser extent. Certain types of lifting threads are characterized by the presence of specialised fixation elements on the thread surface, including notches, “teeth”, cones, or dents. These textural structures play a critical role in anchoring tissues, preventing retraction to their original position, and thereby providing a stable lifting effect. Typically, threads of size 1/0 or 2/0 according to the USP classification are used for such purposes and possess the high mechanical strength necessary for stable traction and for withstanding the mechanical load generated by tissue forces.

Reinforcing threads are implants designed for internal stabilization of soft tissue structures and the creation of a supportive dermal framework that promotes remodeling. Their primary mechanism of action occurs through the stimulation of regenerative processes in response to microtrauma rather than through tissue displacement, as observed with lifting threads.

Biostimulating threads are a type of implantable suture material whose primary mechanism of action occurs not through mechanical means but through the activation of tissue regeneration processes. Their biological activity is attributed primarily to their chemical composition and the physiological response of tissues to the implantation of a foreign material, leading to an inflammatory reaction and subsequent remodeling. As a result, stimulation of neocollagenesis and an increase in the density of the dermal matrix are observed around the implanted thread

Polypropylene, a nonpolar, partially crystalline thermoplastic and nonabsorbable polymer, is widely used in medical practice. It is valuable in procedures aimed at achieving long-term effects because of its low tissue reactivity, very low coefficient of friction, and resistance to biodegradation. Its high tensile strength underpins its clinical significance in aesthetic correction protocols, specifically for correcting morphological manifestations of chronological aging, such as blurring of the jawline and deep nasolabial folds.

Silicone threads, resembling elastic bands, represent a distinct class of nonabsorbable implants, differing from traditional suture materials in both composition and functional purpose. The main clinical application of these threads involves surgical interventions requiring dynamic movement, changes in topography, rotation of soft tissues, or temporary fixation of anatomical structures. The implantation of a silicone suture involves its passage through designated tissue layers, targeted positioning, and subsequent reliable fixation.

Despite the active development of biodegradable thread technologies, nonabsorbable threads still retain clinical importance in certain cases of aesthetic and reconstructive surgery. However, the high risk of long-term consequences associated with their use is increasingly prompting revisions of therapeutic strategies in favor of absorbable thread implants, which offer a more favorable safety and biocompatibility profile.

The key limitation of nonabsorbable threads is their permanent presence in tissues, leading to a prolonged inflammatory response through chronic stimulation of foreign body responses. At the histological level, this can be accompanied by granuloma formation, the development of a pronounced fibrous sheath, and fibrous transformation of surrounding structures, particularly in patients with a predisposition to excessive fibroblast proliferation. Aesthetically, these threads are often associated with the risk of visible defects, such as skin retraction at the site of thread passage, contouring, or palpability of the implant, which are especially pronounced during age-related involution of layer II of the facial region

PDO threads are synthetic, biodegradable, and fully absorbable polymers characterized by high biocompatibility and a well-established safety profile. The material degrades through hydrolytic cleavage, with complete metabolic elimination of the threads typically completed within six months after implantation. In their smooth (monofilament) form, PDO implants do not exert traction effects but effectively stimulate neocollagenesis through microtrauma and fibroblast activation. This makes them particularly effective in correcting static wrinkles and generally improving skin quality.

Despite its benefits, PDO thread technology has notable limitations. Its short biodegradation cycle—about six months—may be insufficient for forming a lasting connective tissue framework. Additionally, its nonspecific and unstructured stimulation of neocollagenesis, particularly with superficial thread implantation or in cases of thin dermis, can lead to local fibrosis, thread contouring, and the formation of aesthetically significant irregularities and microdeformations. As a softer, less durable material than the PLLA or PCL, the PDO is less suitable for individuals with significant tissue density, gravitational ptosis, or excess subcutaneous fat. Without supplementary treatments, outcomes may be unstable, particularly in older patients with advanced aging changes.

Facial aging is a complex, multifactorial biological process involving progressive structural, biochemical, and cellular changes across both the cutaneous and subcutaneous tissue layers.

In parallel with advancing insights into the anatomical and molecular basis of facial aging, thread lifting technologies have undergone substantial innovation. These devices have transitioned from rudimentary mechanical lifting tools to multifunctional platforms capable of exerting both structural and regenerative effects. Thread implants composed of P(LA/CL) copolymers functionalised with HA (Hyaluronic Acid) are of particular clinical interest. These hybrid materials offer dual benefits: immediate biomechanical support and prolonged stimulation of dermal remodeling. Notably, the incorporation of controlled-release delivery systems, such as the NAMICA platform, represents a critical milestone, enabling sustained HA bioavailability and improved tissue integration.

The above is not my own work but taken from a comprehensive article on the subject of threads. Should you be considering thread lifting, you can find the full article here:

Burko, P.; Miltiadis, I. Evolution of Thread Lifting: Advancing Toward Bioactive Polymers and Sustained Hyaluronic Acid Delivery. Cosmetics 2025, 12, 127. https://doi.org/10.3390/cosmetics12030127

(Section of Human Anatomy, Department of Biomedicine, Neurosciences and Advanced Diagnostics (BiND), University of Palermo, Via del Vespro, 129, 90127 Palermo, PA, Italy)