Complications in numbers

Ask most training providers how often injectable treatments go wrong and you will get a soothing answer with no numbers in it. Here is the honest version: the UK does not know. There is no national register of aesthetic complications, no denominator counting how many treatments happen each year, and therefore no true incidence rate for anything. What we have instead is a handful of partial datasets, each telling you something real as long as you stay honest about what it cannot tell you.

This guide lays out those numbers, what the clinical literature adds, which complications actually walk through the door, and what that means for how you should train. It is longer on candour than on reassurance, which we think is the correct ratio for people about to put needles in faces.

What the UK actually counts

The most consistent published series comes from Save Face, the PSA-accredited voluntary register, which reports consumer complaints about unregistered practitioners each year.

Reporting year	Complaints received	Source
2020	2,083	Save Face annual report
2021	2,436	Save Face annual report
Latest reported year	2,824	Save Face annual report, also covered in The Times, Feb 2026

Dermal fillers account for roughly 69% of those complaints, with botulinum toxin second (Save Face annual reports). The trend is steady growth, around 36% across the series, in a sector where the number of people injecting has also grown.

Why these are not incidence rates

A complaint count with no denominator is a numerator in search of meaning. Nobody knows how many injectable treatments the UK performs annually, so 2,824 complaints could represent a sector in crisis or a rounding error, and the data cannot distinguish the two. Three further distortions matter. Complaints skew towards patients unhappy enough, and informed enough, to report, so under-reporting is certain. Save Face counts complaints about unregistered practitioners specifically, so it measures the unregulated end of the market rather than the whole of it. And a complaint is not a verified clinical complication; it can be a bad outcome, a bad experience, or both.

So use the Save Face series for what it is, the best available signal of where harm concentrates (fillers, and the unregistered market), not as a risk figure to quote to patients.

What the literature adds

Peer-reviewed work fills in severity where UK surveillance cannot. Vascular occlusion, where filler blocks an artery, is the complication that matters most: rare, genuinely dangerous, and time-critical. Published estimates of its frequency vary widely by technique, product and anatomical area, and we are deliberately not quoting a single rate because no single honest one exists. The consistent findings are less contested: higher-risk zones include the glabella, nose and nasolabial region; cannula technique and anatomical knowledge change the risk profile; and outcomes depend heavily on how fast occlusion is recognised and treated.

Licensed product matters

The MHRA licenses seven botulinum toxin products in the UK: Alluzience, Azzalure, Bocouture, Botox, Letybo, Nuceiva and Relfydess (MHRA, 2026). Anything else being injected in a UK clinic is unlicensed, and unlicensed product is not a theoretical risk. The 2025 botulism cluster, 41 cases reported by the UK Health Security Agency, traced back to unlicensed toxin (UKHSA, 2025). Those patients did not develop a cosmetic complication; they developed a notifiable disease. Verifying that your product comes from a licensed UK pharmacy supply chain is a complication-prevention measure as much as a legal one, and it is one of the questions we suggest asking any employer or trainer in our guide to choosing a training provider.

The five that present

Vascular occlusion

Filler enters or compresses an artery and downstream tissue starts to die. Recognition: blanching at or beyond the injection point, pain out of proportion (or sometimes deceptively little), then dusky, mottled, livedo-pattern skin over minutes to hours. First response: stop immediately, and move to a drilled hyaluronidase protocol without waiting to be sure, because tissue does not wait. Our occlusion recognition video shows what the early signs actually look like on skin.

Delayed nodules

Firm lumps appearing weeks to months after filler, sometimes triggered by illness or vaccination. Recognition: late-onset swelling or discrete nodules at treatment sites, occasionally red and tender. First response: assess whether inflammatory or non-inflammatory, consider infection, and manage per protocol, which may include antibiotics, hyaluronidase or referral. These cases are why follow-up access matters more than a pretty same-day photo.

Infection

Injectables breach the skin, so infection is always on the table. Recognition: spreading redness, heat, swelling and pain beyond the normal 48-hour settle, sometimes with fever. First response: assess promptly, treat or refer per protocol, and document. Prevention is mostly unglamorous asepsis, which is precisely why it gets skipped.

Ptosis

Drooping of the eyelid or brow after toxin, from diffusion or misplacement. Recognition: asymmetry appearing days after treatment, a heavy lid, a dropped brow. First response: reassure honestly (it is temporary, resolving as the toxin wears off), consider the limited pharmacological options, and review your injection pattern so it does not become a habit.

Over-treatment

The frozen forehead, the overfilled lip, the patient who has stopped looking like themselves. This presents less dramatically than occlusion and far more often. Recognition is aesthetic judgement, which is trainable. First response: restraint, honesty about what dissolving or waiting can and cannot fix, and the confidence to decline further treatment. Saying no is a clinical skill; nobody complains to Save Face about the filler you refused to inject.

Protocols beat slides

Every academy shows delegates a slide about vascular occlusion. Very few make delegates physically run the response: recognise, stop, mix, inject, reassess, refer. Under stress you do not rise to the occasion, you fall to your training, and a memorised slide is not training. That is why our foundation course includes a complications drill, and why we publish the occlusion recognition and hyalase protocol videos for anyone to watch, whether or not they train with us.

Before you inject anyone

Training that takes complications seriously should give you all of the following. Treat this as a checklist when comparing providers.

1. Facial anatomy taught around danger zones as well as treatment points.
2. A written vascular occlusion protocol you have physically rehearsed rather than skimmed.
3. Hyaluronidase handling: when, how much, how to reconstitute it, and the prescriber arrangement that makes it lawful (see the insurance and prescribing guide).
4. An emergency kit list, and the face-to-face prescribing route that stocks it legitimately.
5. Consent and expectation-setting that names real risks in plain English.
6. Follow-up and escalation pathways: who you call, who the patient calls, at 2am.
7. Supervised cases with feedback, at a ratio where the trainer actually watched you (ours is 4:1 or better).
8. A named route for case support after the course ends.

What we do not know

No national complications registry exists, so the honest answer to “how risky is this?” remains “nobody can fully tell you”. Under-reporting is structural: patients treated by unregistered practitioners often will not report, practitioners have little incentive to publicise their own complications, and the Yellow Card scheme captures only a slice of device and medicine events. England’s proposed licensing scheme (government response, August 2025) could change this, since licensing creates a register of practitioners and premises that data could eventually hang off; progress is tracked in our licensing tracker. Until then, any trainer quoting you a precise national complication rate is quoting something that does not exist.

Where Aurelia stands

We would rather publish the uncomfortable numbers than imply the comfortable ones. Our foundation botox and dermal filler course drills the occlusion response rather than describing it, cohorts are capped at eight with a 4:1 delegate-to-trainer maximum, and alumni keep access to monthly case-review calls because complications do not respect course end dates. If you want to check whether your background fits before committing, the route finder and free eligibility review are the honest place to start.

This guide is educational information for practitioners, not clinical advice for an individual patient. Figures checked 11 July 2026.