PDO Threads vs Silhouette Soft: Which Thread Is Right for You?
PDO threads and Silhouette Soft are both absorbable threads used to lift and support sagging skin without surgery, but they are made from different materials, hold tissue in different ways and suit slightly different goals. In general, PDO threads are versatile and widely available, with many shapes for both lifting and skin quality, while Silhouette Soft uses a polylactic acid (PLLA) based thread with small cones that gives a gentle lift and is known for gradual collagen stimulation. Neither is "better" in every case. The right choice depends on your degree of laxity, your face shape, what you want to achieve and the experience of the doctor placing them.
This guide explains how each thread works, how results and recovery tend to compare, and which questions to ask before deciding.
What PDO threads are
PDO stands for polydioxanone, a dissolvable material that has been used in surgical sutures for decades. In aesthetic medicine, PDO threads come in several designs:
- Mono threads: smooth, thin threads placed in a mesh pattern to support skin quality and mild firmness rather than lift.
- Screw or twisted threads: wound threads that add a little more volume and support in small areas.
- Barbed or cog threads: threads with tiny barbs cut or moulded along their length. These grip the tissue under the skin and are used for lifting the cheeks, jowls and jawline.
PDO generally dissolves over roughly six to eight months. As it breaks down, the body forms some new collagen around the thread path, which is thought to help results last a little beyond the life of the thread itself. Because there are so many PDO designs, doctors can combine types in one session, for example cog threads for lifting and mono threads for texture.
What Silhouette Soft is
Silhouette Soft is a branded thread made mainly from poly-L-lactic acid with a copolymer. Instead of barbs, it carries small absorbable cones spaced along the thread. The cones anchor the tissue, and the thread is placed through a small number of entry points and pulled into a new position.
PLLA is the same family of material used in some collagen-stimulating injectables. It tends to break down more slowly than PDO, often over a period of around a year or more, and is associated with a gradual collagen response. Many people notice an initial lift right away, followed by a subtler, more natural-looking firmness that develops over the following months.
How the lift and feel compare
The main practical differences people notice are in how strong the lift feels and how natural it looks:
- Grip: barbed PDO threads have many small anchoring points along the thread, which can give a firm, immediate hold. Silhouette Soft's cones distribute tension in a different way, which some doctors feel creates a softer, more even lift.
- Immediate result: both can show a visible change on the day, but this is partly blurred by swelling. Results usually settle over two to four weeks.
- Collagen effect: both stimulate collagen to some degree. PLLA is often described as having a longer-lasting stimulating effect, though direct head-to-head research is limited.
- Flexibility: PDO's range of designs means it can treat more areas, including the neck, brows and fine textural concerns. Silhouette Soft is mostly used for the mid-face, jowls, jawline and neck.
How long results last
Longevity varies a lot from person to person. Age, skin thickness, sun exposure, weight changes and how much sagging was present at the start all play a role. As broad guidance:
- PDO cog threads: visible lifting is often described as lasting around six to twelve months, with some people reporting longer.
- Silhouette Soft: results are frequently quoted at around twelve to eighteen months.
These are general ranges, not guarantees. Threads do not stop the natural ageing process, and many people choose top-up treatments or combine threads with other procedures to maintain the effect.
Recovery, side effects and risks
Recovery is broadly similar for both. Expect some swelling, tenderness and possibly bruising for several days to about two weeks. Common, usually temporary effects include:
- A feeling of tightness or pulling, especially when opening the mouth wide
- Small dimples or puckering near entry points or along the thread path
- Mild asymmetry while swelling settles
Less common risks include infection, a thread becoming visible or poking through the skin, prolonged irregularities and, rarely, nerve irritation. Because PDO cog techniques often involve more threads, some people experience slightly more puckering, while Silhouette Soft's cones can sometimes be felt under thin skin for a while. In both cases, technique and correct placement depth matter more than the brand.
Who each option may suit
As a starting point for discussion with your doctor:
- PDO threads may suit people who want a combined approach, mild to moderate jowling, a flexible treatment plan across several areas, or skin-quality improvement alongside lifting.
- Silhouette Soft may suit people with mild to moderate mid-face or jawline sagging who prefer a softer, gradual result and are interested in a potentially longer-lasting effect from fewer threads.
- Neither may be ideal for those with very heavy, loose skin, significant fat descent or thin, fragile skin, where surgery or other approaches may give a more meaningful result.
Practical points for visitors to Korea
Thread lifts are commonly offered in Korea, and both PDO and PLLA based threads are widely used. If you are visiting, plan for swelling and possible bruising, avoid scheduling important photos or events in the first week, and ask about follow-up timing before you fly home. Flying a few days after treatment is generally considered acceptable for most people, but you should confirm with your doctor and ask what to do if a thread becomes visible after you leave.
Frequently asked questions
Is Silhouette Soft more painful than PDO threads?
Discomfort is similar and depends more on the number of threads and the area treated. Local anaesthetic is normally used for both, and most people describe pressure and tugging rather than sharp pain.
Can PDO threads and Silhouette Soft be used together?
Some doctors combine thread types, for example a lifting thread with PDO mono threads for skin quality. Whether this makes sense depends on your anatomy and goals.
Are the threads removed later?
No. Both are designed to dissolve naturally. In rare cases where a thread causes problems, a doctor may remove part of it.
Can I have fillers or Botox with a thread lift?
Often yes, and combination treatment is common. Your doctor may recommend spacing treatments or doing them in a specific order to protect the threads and reduce swelling.
Getting the right advice
Choosing between PDO threads and Silhouette Soft is less about the product name and more about matching the technique to your face. A qualified dermatologist or experienced aesthetic doctor can assess your skin laxity, bone structure and expectations, explain the realistic results and risks for you, and recommend whether threads are a good option at all. Book a consultation for personalised advice before committing to treatment.
