# Types of Fat-Dissolving Injections — How Carboxytherapy, LLD, and Contour Injections Differ > Category: treatment-guide > Published: 2026-07-27 01:00:53.590196+00 > Source: https://kdermzip.com/en/blog/fat-dissolving-injection-types-carboxy-lld-contour ## Types of Fat-Dissolving Injections — How Carboxytherapy, LLD, and Contour Injections Differ Many people considering [fat-dissolving injections](/en/treatments/lipolysis-injection) want to reduce localized fat in the face or body. During a clinic consultation, however, terms like carboxytherapy, LLD (lipolysis), and contour injections can sound confusing. This article outlines, at a general medical information level, how the main categories of fat-dissolving injections work and what distinguishes them. ### How do fat-dissolving injections work? Broadly speaking, fat-dissolving injections fall into two groups: ingredients that destabilize fat cell membranes so cell contents break down and are cleared, and ingredients that promote local blood flow and metabolism to support fat breakdown. Formulations are generally categorized as deoxycholic acid-based, phosphatidylcholine (PPC)-based, or carbon dioxide-based (carboxytherapy), with the chosen ingredient and concentration varying by treatment goal and site. It's worth noting that a single session rarely produces a dramatic change in body contour — visible results are more often reported when repeated sessions are combined with lifestyle management. ### What sets carboxytherapy apart? [Carboxytherapy](/en/treatments/carboxytherapy) involves injecting medical-grade carbon dioxide gas beneath the skin. It is thought to trigger a localized Bohr effect that increases oxygen delivery, supporting circulation and metabolism, and is commonly used for under-eye dark circles, cellulite, and localized fat management. Because it relies on a physiological gas response rather than a drug compound, its mechanism differs from other fat-dissolving injections, and the number and interval of sessions needed vary by treatment site and goal. ### What characterizes LLD (lipolysis) injections? LLD typically combines lipolytic enzymes or agents that act on fat cell membranes, and the exact formulation and naming can vary between clinics. Deoxycholic acid-based agents are understood to disrupt fat cell membranes, prompting cell breakdown, and are often applied to relatively larger localized fat areas such as the submental area, abdomen, or upper arms. Temporary swelling, bruising, or pain may occur after treatment, and recovery time and intensity vary from person to person. ### Are contour injections mainly used on the face? As the name suggests, [contour injections](/en/treatments/contour-injection) often refer to combination formulas developed specifically to refine facial lines. They typically pair fat-dissolving ingredients with anti-swelling or anti-inflammatory components to address puffiness and localized fat around the jawline, cheeks, or double chin. Formulation and concentration are generally designed differently from injections used on the torso or limbs, and even products sharing the name 'contour injection' can differ in composition between clinics. ### What should you check before treatment? Response and recovery from fat-dissolving injections can vary depending on the practitioner's experience and the individual's skin and constitution. Treatment may be restricted during pregnancy or breastfeeding, while taking certain medications, or if you have a blood clotting disorder, so a thorough consultation beforehand is important. Some ingredients can also cause allergic reactions or localized inflammation, so if abnormal symptoms persist after treatment, follow up with your physician. ### How long does swelling last after treatment? Swelling and minor bruising commonly appear for a few days after injection and tend to subside gradually, though this varies by injection site, ingredient, and individual constitution. Since recovery speed and degree differ from person to person, if swelling persists unusually long or pain worsens, it's advisable to have it evaluated by a physician rather than making a self-assessment. This information is for general reference only. An accurate diagnosis and treatment plan require consultation with a board-certified dermatologist. [Skin Health Blog](/en/blog) ## Related Resources - Blog post: https://kdermzip.com/en/blog/fat-dissolving-injection-types-carboxy-lld-contour - All guides: https://kdermzip.com/en/blog - K-DermZip: https://kdermzip.com