What have you done to your face?” I ask a colleague visiting from Germany, his skin akin to that of a lit candle. “Exosomes,” he replies, smiling, passing a hand across his luminescent visage.

I’m not surprised. Recently, it’s been hard to move for talk of exosomes. A skin-rejuvenation treatment that’s reached our shores after years of popularity in South Korea, exosomes have become synonymous with radiant skin and minimal downtime – a beauty editor’s happy place. There are in-clinic exosome treatments and at-home options.

On social media, people are reporting back after having exosomes injected into their scalps for excess hair shedding. (This, I hasten to add, is not legal in the UK yet.) So what are these genius things and why have they got the skincare industry so abuzz?

What are exosomes?

“Exosomes are tiny, extra-cellular nano vesicles – very small particles that can penetrate easily and are involved in cell-to-cell communication,” facialist to the stars and editors alike, Sarah Chapman, explains to me.

Think of them like clever couriers carrying biological information between cells, all the while carrying proteins, lipids, peptides and other genetic material along with them. Most impressively, exosomes accelerate skin healing and skin regeneration.

These ultra-reparative, anti-inflammatory messengers target skin texture and hydration, as well as supporting collagen and elastin production, and maintaining the integrity of the skin barrier.

Where do exosomes come from?

In the UK, the only legal exosomes are those that aren’t derived from humans – though we do naturally produce them. Instead, fish, bovine, yeast-cultured and plant exosomes, which can be manipulated to mimic human exosomes, are all that’s currently on offer.

Celebrity facialist Shane Cooper uses E50 Korean exosomes, derived from the fibroblast cells of salmon, and says their concentration and efficacy rate has helped him to repair his own skin barrier and calm down rosacea flare-ups. (E50 Korean exosomes aren’t to be confused with polynucleotides, another salmon byproduct also used to stimulate cell regeneration.)

What happens in an exosome treatment?

The way exosomes are administered can vary, though they’re usually introduced to the skin via injection or applied to the skin after a round of microneedling. There is a third, needle-free way, but more on that later.

“Exosomes can be delivered into the skin via direct injection – mesotherapy style,” aesthetic doctor and founder of the eponymous clinic Dr David Jack tells me, “which is where tiny, superficial injections place the exosome solution precisely into the dermis [the inner of the two main layers in the skin].”

The method you’re most likely to come across is microneedling. “Microchannels are created in the skin, which then allow topical exosomes to penetrate,” Dr Jack says, making me think of a crumpet slathered in exosome-rich butter. These microchannels allow the exosomes to reach deeper into the skin and work their magic where it’s most needed.

What skin concerns can exosomes treat?

Besides being suitable for innumerable skin concerns – from acne scarring to improving skin volume and calming skin redness and irritation – exosome treatments are unique due to the remarkably short recovery times required.