What Are the Different Types of Toxin?

A practical guide to UK-licensed botulinum toxin products for new injectors

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First, the Basics

All aesthetic botulinum toxin products contain the same active ingredient: botulinum toxin type A, a protein produced by the bacterium Clostridium botulinum. Injected in tiny, precisely targeted doses, it temporarily blocks the nerve signal that tells a muscle to contract. The muscle relaxes, and the overlying skin smooths out. The effect lasts 3–6 months depending on the product, dose, area, and patient.

What varies between brands is not the core mechanism — it’s the formulation, the protein complex surrounding the active toxin, the unit system, and the clinical behaviour. These differences matter practically, and understanding them is essential before you treat anyone.

The UK-Licensed Products

As of 2026, there are five botulinum toxin type A products licensed for aesthetic use in the UK:

Brand	Generic name	Manufacturer	Vial size	Unit type	Key notes
Botox®	OnabotulinumtoxinA	Allergan / AbbVie	50u, 100u	International units (IU)	Longest track record. Contains 900kDa complex. Requires refrigeration.
Azzalure®	AbobotulinumtoxinA	Galderma / Ipsen	125u	Speywood units	Slightly quicker onset and wider diffusion than Botox. Aesthetic-specific licence. Requires refrigeration.
Bocouture®	IncobotulinumtoxinA	Merz	50u, 100u	International units (IU)	Only product free of complexing proteins (naked 150kDa neurotoxin). Room temperature storage. 1:1 ratio with Botox.
Alluzience®	AbobotulinumtoxinA	Galderma	125u ready-to-use	Speywood units	Same molecule as Azzalure, in ready-to-use liquid form — no reconstitution needed.
Relfydess®	RelabotulinumtoxinA	Galderma	150u	International units (IU)	Ready-to-use liquid form — no reconstitution needed. Fastest onset (24–48 hrs). Duration up to 6 months in studies.
Nuceiva®	PrabotulinumtoxinA	Evolus	100u	International units (IU)	UK-licensed product. Well established in North America and Asia. Requires reconstitution and refrigeration.
Letybo®	LetibotulinumtoxinA	Croma-Pharma (Hugel)	50u, 100u	International units (IU)	Newer to UK. Market leader in South Korea. EMA-approved. Requires reconstitution.

A note on Dysport®: it’s the same molecule as Azzalure and Alluzience (abobotulinumtoxinA) but in the UK is licensed for therapeutic use only — hyperhidrosis and muscle spasticity. Azzalure and Alluzience are the UK aesthetic licences for this molecule.

The Most Important Rule: Units Are NOT Interchangeable

🚨  Critical Safety Point for New Injectors Each brand uses its own unit system. Botox and Bocouture use International Units (IU). Azzalure and Alluzience use Speywood units.Speywood units are NOT the same as International Units. They are measured differently and you cannot swap one for the other at a 1:1 ratio.If you learn to dose in Botox units and switch to Azzalure without adjusting, you will significantly underdose or overdose your patient.Always check which unit system your product uses before reconstituting or dosing.Always follow the product’s own SmPC (Summary of Product Characteristics) for guidance on dosing and dilution.

The approximate conversion between the two unit systems is:

Botox / Bocouture (IU)	Azzalure / Alluzience (Speywood)	Clinical notes
4 IU	10 Speywood	Equivalent glabellar dose per site (approximate)
20 IU	50 Speywood	Typical glabellar total dose (approximate)
20 IU	50 Speywood	Typical forehead total dose (approximate)

These are approximations only — not precise equivalents. The exact dose you need may vary between patients, areas, and your clinical technique. Start conservatively, especially when using a new product, and review at two weeks.

A Word on ‘Grey Market’ Products

⚠️  Don’t Use Unlicensed Toxin Products Products like Botulax, Zentox, Regenox, and similar Korean-market botulinum toxins are NOT licensed in the UK. They may also go by other brand names.Using an unlicensed medicine without specific justification is a regulatory and clinical governance issue. It also puts your patients — and your registration — at risk.If a supplier is offering botulinum toxin products at a significantly lower price than the established brands, ask why. Legitimate licensed products have a cost base that reflects their manufacturing, clinical trial investment, and cold chain requirements.If you’re unsure whether a product is licensed in the UK, check the MHRA website or the Electronic Medicines Compendium (EMC) before purchasing or using it.

Which Product Should New Injectors Start With?

This is genuinely a matter of training, clinic preference, and what your prescriber uses. Most Foundation courses teach one product first so you build familiarity and confidence before switching. The key principles for new injectors:

• Learn one product thoroughly before switching between brands
• Know the unit system for the product you’re using — before you reconstitute, not after
• Dose conservatively and review at two weeks. You can always top up; you can’t take it back
• Read the SmPC for every product you use. It’s not optional.
• If your clinic switches products, treat it as a relearning exercise — don’t assume the same doses apply

Product knowledge — including reconstitution, dosing, storage, and unit systems — is covered in depth on all Acquisition Aesthetics Foundation and Intermediate courses. You won’t be left to figure this out on your own.

Learn Toxin Technique the Right Way, From the Start Product knowledge, dosing safety, and injection technique are covered from day one on our Foundation course. Clinically led, anatomy-first training for doctors, nurses, and dentists. ➤ Explore Our Foundation Course

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