Hyaluronic acid (HA) is not one ingredient – it is a family. The same sugar chain behaves completely differently depending on its length: molecular weight determines whether HA penetrates and signals, hydrates the surface, or forms a durable film. Understanding this scale is understanding modern aesthetic medicine – and it is the logic behind the entire Fusion Meso range.
The shortest chains penetrate deepest and act as biological signals rather than simple hydrators. This is the territory of ACURHYAL – Class III medical devices certified under MDR (EU) 2017/745 for collagen stimulation by mesotherapy. ACURHYAL is a precisely engineered ULMW hyaluronic acid of exactly 38 monomers (15.2 kDa), produced by controlled sonicated fragmentation rather than random enzymatic hydrolysis – ensuring a homogeneous chain length most commercial HA cannot offer. At this size, HA stops being a moisturiser and becomes a messenger: it binds the CD44 and RHAMM receptors of fibroblasts in the deep dermis, activating collagen type I and III synthesis. In a 2024 published clinical study (ultrasound and histology), ULMW-HA with amino acids increased dermal thickness by 27.3%, doubled the number of capillaries and multiplied epidermal EGF reactivity twenty-fold.
Obtained by patented enzymatic fragmentation, HA XS penetrates the epidermis rapidly, calms inflammatory factors (documented IL-6 -70%, TNF-α -44%) and supports repair of UV- and acid-stressed skin. Found across Fusion Meso home care: DEEP CLEANSER, HYALURONIC DROPS, HYALURONIC MOISTURIZER, PROBIOTIX CREAM and ACN CORRECTOR.
The versatile weight used in most sterile vials: enough substance to hydrate and improve elasticity (+27% at 8 weeks documented), light enough to spread evenly through treated skin. It is the HA backbone of F-XFC+, F-LIFT+ FACE, F-HYDRALIX and most in-clinic protocols.
Long chains bind up to 1,000 times their weight in water at the skin surface and upper layers. The F-HA line is built on high-weight HA: F-HA (pure), F-HA LIFT (with GHK-Cu and NCTC 135), F-HA GLOW (with tranexamic acid) and F-HA ULTRA (with EGF and FGF) – the topical alternative to fillers, without cross-linking agents.
Chemically bridged HA resists degradation by hyaluronidase and forms a breathable 3D film – a “micro-reservoir” of water lasting up to 24 hours. Used in HA DEEP FILLER (the same HA type as dermal fillers, to prolong injection results), MESO LIFT CREAM and EYE SORBET.
A complete HA strategy layers the weights: ULMW biostimulation in-clinic (ACURHYAL), medium/high-weight vials during procedures, XS and cross-linked HA in home care. Each weight does one job well – the art is in the sequence.
No – lower goes deeper but does a different job. Surface hydration and film protection need long chains; biostimulation needs short ones. That is why single-weight “HA serums” underperform layered professional protocols.
No – they are non-cross-linked topical/mesotherapy formulations. Injectable collagen biostimulation is the role of the ACURHYAL certified medical devices, used exclusively by practitioners.
