Exosomes Need a Specification, Not a Buzzword

Exosome is currently one of the most used (and least specified) words in professional skincare. The term describes extracellular vesicles: nano-sized particles released by cells that carry proteins, lipids and nucleic acids between cells. That biology is real and genuinely interesting. The problem is what happens between the biology and the label.

We see the gap most clearly when a clinic brings us two products with "exosome" on the box and asks which one is better. Often the only honest answer is that neither box tells us enough to say. This article is about what "enough" looks like.

The biology, briefly

Cells shed vesicles constantly. Some are released when internal compartments fuse with the cell membrane, and these are the ones classically called exosomes. The research community now prefers the umbrella term extracellular vesicle, because in practice the different populations overlap in size and are hard to separate cleanly. The current consensus guidance from the International Society for Extracellular Vesicles, known as MISEV2023, treats "small EV" as an operational label for particles usually under about 200 nanometres, and is careful to note that the measured size depends on the method used to measure it.

The reason vesicles matter is their cargo. A vesicle is a membrane-wrapped parcel, and whatever the parent cell packed into it is what the receiving cell gets: signalling proteins, lipids, messenger and regulatory RNA. In wound-healing and regenerative research, that parcel is the point. Strip the cargo out and the vesicle is just a lipid bubble.

What a specification looks like

Products described as exosome differ enormously. Four questions define a meaningful specification:

Source. What cells or material do the vesicles come from: plant, human cell culture medium, or another origin? Each carries different regulatory constraints and different plausibility for skin benefit. In the UK and the EU this question has a hard regulatory edge. Annex II of the cosmetics regulation retained from Regulation (EC) 1223/2009 prohibits cells, tissues or products of human origin in a cosmetic, which means a cosmetic product cannot lawfully contain vesicles harvested from human cells or their culture medium. Plant-derived vesicles, such as those isolated from centella and other botanicals, are not caught by that entry, which is one reason they dominate the professional topical market.

Characterisation. Has the manufacturer measured particle size, concentration and identity, or is exosome being used loosely for a filtrate or lysate? The MISEV guidance treats particle concentration and size distribution as core measurements, asks for evidence of molecular markers that identify the vesicles, and expects the manufacturer to show that the separation method actually removed the non-vesicle material. A supplier who can show nanoparticle tracking or electron microscopy data is telling you something; a supplier who cannot is also telling you something.

Cargo. Which growth factors, proteins or RNA species are actually present, and at what levels? The cargo is the mechanism; without it the vesicle is an empty envelope. For a plant vesicle, the relevant cargo is the plant's own actives and lipids, which is a different proposition from a human stem-cell secretome and should be described as such.

Delivery. How is the material stabilised in the formula, and what supports the claim that it remains active on skin? Vesicles are fragile. Heat, freeze-thaw cycles and surfactants can rupture them, so the format (freeze-dried powder reconstituted at the point of use, encapsulated serum, sheet mask) is part of the specification, not a packaging detail.

The questions to ask a supplier

• What is the source organism or cell type, and is that permitted in a cosmetic in the UK?
• What is the particle size distribution and concentration, and how was it measured?
• What markers or cargo have been identified, and is there a batch certificate?
• What is the stabilisation method and the shelf life once opened or reconstituted?
• Is the evidence for this product, or for exosomes in general?

Korean laboratories are among the most active in vesicle research, and well-specified products do exist. The practitioner's job is to hold the category to the standard of a specification sheet, not a buzzword.

What this means in clinic

The exosome products in our range are plant-derived, which keeps them inside the cosmetic rules and gives you a clear answer to the source question before anything else. The ISOV HD EXO LLT PRO TRI Fills combines plant exosomes with nanoencapsulated gold in an ethosome carrier, and practitioners use it with microneedling and device-assisted infusion for ageing and pigmentation concerns. The EXO LLT PRO AC Fills is the same platform formulated for acne-prone and textured skin. For the recovery phase, the Pfecta Exosome Masks with Cica pair centella-derived vesicles with the centella actives themselves in a sheet format that is simple to use straight after a procedure.

In the treatment room, say what the product is. "A plant-derived vesicle serum used to support recovery and hydration after your treatment" is accurate, explainable and defensible. "Stem-cell exosomes" is none of those things when the box does not say so.

See the full range in our exosomes collection, or read our guide to PDRN, exosomes and PLLA skin boosters.