Thread Basics FAQ
Part 1 — The procedure and the product category
Q1. What is a thread lift?
A thread lift is an in-office procedure in which absorbable threads are placed under the skin to reposition tissue and stimulate a collagen response. It typically takes 30–60 minutes under local anesthesia for a facial treatment (GLPbase; APAX Medical).
What happens on the timeline:
| Material | Reported absorption | Sources |
|---|---|---|
| PDO | 4–9 months | MINT 6–8 mo, Auro 6–9 mo, Yasa 4–6 mo, AEVEpdo 6–8 mo |
| PCL | 12–36 months | Deenora 12–18 mo, Auro 24–36 mo, XLINE "2–3 years" of effects |
| PLLA | 12–24 months | Auro 12–18 mo, APAX 1–2 years |
Note an unresolved conflict in one source: the Deenora catalog states "1–2 years" for PDO while its own website FAQ states 6–8 months. Where a supplier's own documents disagree, the IFU governs.
Absorption is not "zero trace by a fixed date." Absorbable thread materials are assessed for biological safety including degradation products under the ISO 10993 series; passing that evaluation supports a safety assessment for the intended use — it does not establish complete clearance for every gauge, batch or individual. One published case documents a thread too thick to absorb, requiring removal (PMC7507174).
Part 2 — The three materials
Q4. What are PDO, PCL and PLLA threads?
Three absorbable polyester families, all with established use as surgical suture materials.
PDO — polydioxanone. The most documented material in thread lifting and the broadest design range. Typically monofilament: one solid strand with no braided interstices. In the US, absorbable polydioxanone surgical suture is a Class II device type with special controls under 21 CFR 878.4840. Reported absorption 4–9 months (brand claims).
PCL — polycaprolactone. Positioned by manufacturers as the slowest-absorbing of the three, with reported figures of 12–36 months depending on brand . Commonly stocked when a clinic wants a longer-duration option in its menu.
PLLA — poly-L-lactic acid. Best known in aesthetics from injectable collagen biostimulators. Described as working gradually rather than delivering only an immediate pull. Regulatory note: the only FDA-cleared absorbable lifting thread device, Silhouette InstaLift (midface), contains 18% PLLA (ScienceDirect). Reported absorption 12–24 months.
All three are available across multiple thread designs. A PCL mono thread and a PCL cog thread do not share a construction — material and design are independent variables (Q7).
Per-material detail: PDO · PCL · PLLA FAQ pages.
Q5. Which material lasts the longest?
By reported absorption, PCL is the longest at 12–36 months, followed by PLLA at 12–24 months and PDO at 4–9 months (all manufacturer claims, per Q3).
Three qualifications that matter more than the ranking:
- Absorption time is not result duration. Because results combine the mechanical effect with a collagen response, they outlast the thread. PDO threads absorbing in 6–8 months are associated with results reported at 12–18 months (GLPbase).
- Figures vary within a single brand. A figure from one brand does not transfer to another brand's SKU.
- The comparative claim "PCL stimulates more collagen" is not established. But comparative superiority claims require competent and reliable scientific evidence before they can be repeated as fact. We publish material comparisons only with their evidence.
Longer absorption is not automatically the better choice — it is a longer commitment for the patient and a different revenue and re-treatment cycle for the clinic. Selection by goal: Q6.
Q6. Which material should a clinic choose?
Choose by treatment goal, not by duration ranking:
| Goal | Material commonly stocked | Reasoning |
|---|---|---|
| Broadest design coverage; most documented category | PDO | Widest range of designs, gauges and lengths in verified catalogs; most represented in thread-lift literature |
| Longer-duration option in the menu | PCL | Longest reported absorption (12–36 months ⚠) |
| Gradual, progressive change | PLLA | Associated with gradual tissue stimulation rather than immediate pull alone |
Most clinics stock more than one. PDO covers the majority of a standard menu; PCL and PLLA extend it where a longer-duration or gradual-change option is wanted.
These are positioning descriptions from manufacturer product education, not clinical rankings, and no material is universally superior. Which material suits a specific patient and area is determined by the treating practitioner.
Area-by-area mapping: Application Areas FAQ. Stocking and menu planning: Wholesale & Ordering FAQ.
Part 3 — Thread designs and sizes
Q7. What is the difference between mono, screw, cog and the other designs?
The difference is surface architecture, and it determines whether a thread lifts or not.
| Design | Construction | What it does | Verified USP range |
|---|---|---|---|
| Mono / smooth | Single smooth filament, no barbs | No repositioning — skin quality and collagen stimulation | USP 6-0 / 7-0 |
| Screw / spiral | One or more filaments twisted around or along a carrier | Increased tissue surface contact; gradual stimulation | USP 6-0 / 7-0 |
| Cog / barbed | Angled projections along the thread | Anchors and repositions tissue — this is what produces lift | USP 2 |
| Tornado / tornado screw | Twisted or spiral variant | Higher surface profile; verify exact construction per SKU | Per catalog |
| Fishbone | Specialized multi-projection layout | Product-specific; catalog and IFU review required | USP 3 |
| Mesh / multi / molding | Multi-strand constructions | Product-specific options | Per catalog |
| Double needle | Two-needle delivery variant | Per catalog designation | Per catalog |
Cog 6D, mini cog screw and multi lines carry their own designations — see the Thread Specifications Guide.
The practical distinction: barbs lift, smooth surfaces do not. A mono thread is not a weaker cog thread — it is a different tool for a different goal. Screw and tornado designs sit between the two by increasing surface contact without barb anchoring.
One caution: design names are catalog terminology, not standardized constructions. Two products named "cog" can differ in barb geometry, base filament diameter and delivery format. Compare the product image, dimension table and specification sheet for the exact SKU.
Design detail and full family list: Thread Types & Specifications FAQ.
Q8. What is the difference between a sharp needle and a cannula?
A sharp needle has a cutting tip and pierces the skin directly. A cannula has a blunt tip and is designed to follow tissue planes, which reduces puncture risk in vascular areas.
Verified examples from the Deenora:
| Product | Delivery | Gauge | USP |
|---|---|---|---|
| Eye Thread | W cannula (blunt) | 30G | 7-0 |
| Nose Thread | L cannula (blunt) | 19G | 2 |
| COG 2-1 | L cannula (blunt) | 19G | 2 |
Blunt cannulas appear on the highest-risk anatomical areas (periorbital, nasal), where published case literature documents complications from incorrect placement (PMC7507174). Sharp needles are used where the technique requires direct penetration.
This is a delivery-system specification, not a quality ranking — both formats are offered across gauges, lengths and designs. Which format suits a technique and area is a procedural decision for the trained practitioner, made per the product IFU.
Q9. What do gauge, USP size and the two length numbers mean?
Four separate measurements, frequently confused.
Gauge (G) — outer diameter of the delivery needle or cannula. Higher number = finer needle. 30G is finer than 27G; 19G is much larger than 27G. Verified range: 18G–30G.
USP size — suture-diameter class printed for the thread itself, a different scale from gauge. In verified catalogs, USP 7-0 appears on the finest lines (Eye Thread) and USP 2 on cog and nose lines. Gauge and USP cannot be converted into each other — they describe two different components of one product: the delivery instrument and the implanted thread.
The two lengths. A code such as 60/70 mm is needle length / thread length. The first number is the delivery needle; the second is the absorbable thread that remains in tissue.
Reading a full code:
Mono 26G, 60/70 mm= smooth PDO mono thread · 26G sharp needle · 60 mm needle · 70 mm threadMono 29G, 38/50 mm= 29G sharp needle · 38 mm needle · 50 mm threadMono Screw 29G, 50/70 mm= 29G sharp needle · 50 mm needle · 70 mm screw-thread
Q10. How many threads come in a pack?
Pack counts are brand-dependent, not standardized.
Because pack size varies — confirm the unit quantity on the label at receipt, along with the remaining shelf life.
Pack configurations and pricing for our range: Wholesale & Ordering FAQ.
Part 4 — Handling, safety and getting started
Q11. How are threads packaged and stored, and what is the shelf life?
Threads are supplied as sterile, single-use devices. Our published guidance: shelf life 3–5 years per label, storage at 5–25°C in a cool, dry place away from direct light.
Other brands publish different windows — Deenora's FAQ states 36 months at 15–25°C, Auro states a 2-year shelf life. Where figures differ, the label and enclosed IFU on the pack you received govern.
Never use a pack whose sterile barrier is damaged, and never resterilize a single-use device.
Storage and shipping detail: Shipping & Storage FAQ · Shipping Policy.
Q12. Are thread lifts safe, and what are the side effects?
PDO, PCL and PLLA are absorbable suture-class materials with decades of surgical use, and no invasive procedure is risk-free.
Rates from the largest available meta-analysis — 26 studies, 2,827 patients (medRxiv 2025):
| Effect | Rate |
|---|---|
| Bruising | ~26% |
| Swelling | ~16% |
| Pain | ~11% |
| Temporary numbness | ~10% |
| Dimpling / asymmetry | ~7% |
| Palpable or visible threads | ~6% |
| Thread exposure | ~5% |
| Infection | ~2% |
Most resolve within days to weeks. The same analysis identifies operator technique as the main determinant of complication rates — which is why training and anatomical knowledge matter more than material choice for safety outcomes.
Claims of "no side effects" are not accurate for any invasive procedure. Persistent redness, worsening pain or fever should be reported to the practitioner immediately, and an exposed thread should never be pulled by the patient — a licensed practitioner must manage it.
Contraindications, complication management and per-area risk: Safety & Contraindications FAQ.
Q13. What should a clinic order first?
A practical starting sequence:
- Define the treatment areas on your menu — face, jawline, neck, eye area, nose or body
- Match the design to the goal — cog for repositioning, mono and screw for skin quality (Q7)
- Choose the material — PDO for the broadest coverage, PCL or PLLA to extend duration options (Q6)
- Match the delivery format to the area — cannulas on periorbital and nasal work, sharp needles elsewhere (Q8)
- Confirm the dimensions — gauge, needle length, thread length and USP size (Q9)
- Check the documentation — IFU, label, expiry, lot number and applicable certificates (Compliance Guide)
Steps 1–2 follow from the clinical menu and belong to the practitioner. Steps 3–6 are procurement decisions that can be executed against a specification table.
Most clinics start with a PDO mono and cog range covering their two or three highest-volume areas, then extend into PCL or PLLA once the menu is established.
Starter configurations and volume pricing: Wholesale & Ordering FAQ. Training and certification: Training & Certification FAQ.
Sources for this FAQ
- 21 CFR 878.4840 — Absorbable polydioxanone surgical suture — Class II classification with special controls.
- ScienceDirect — polyglycolide / InstaLift — PLLA content of the cleared midface lifting-thread device.
- medRxiv 2025 meta-analysis — 26 studies, 2,827 patients; side-effect rates and technique as determinant of complications. [TBC — insert the exact article DOI/URL from the Phase-1 source pool before publishing.]
- PMC7507174 — published complication cases including extrusion and a non-absorbing thread requiring removal.
- APAX Medical — Facelift Thread Lifting — procedure duration, recovery windows and clinical-literature references (Suh 2015; Kim 2016).
- GLPbase — PDO Threads Guide — professional education on materials, designs, duration and regulatory status.
- ISO 10993-1 — biological evaluation of medical devices.