Service & Knowledge · Medical Patient Information Article
Botulinum Toxin Products: A Patient’s Guide
Several botulinum toxin preparations are approved on the German market. They differ in molecular structure, manufacturing process and pharmacological profile — but not in their fundamental efficacy.
A note on terminology: Many patients search for “Botox” — a brand name of one single product that has become a colloquial umbrella term. The active substance is botulinum toxin type A, contained in several licensed medicinal products. All of them are prescription-only and are injected exclusively by the physician after a medical examination. This page uses the substance name throughout — it refers to the same treatment commonly known as a Botox treatment.
Legal framework. This article is a medical patient-information piece provided under the physician’s duty to inform pursuant to § 8 of the German Medical Professional Code (MBO-Ä). It contains no recommendation or advertising for any specific prescription-only preparation within the meaning of § 10 (1) of the German Therapeutic Products Advertising Act (HWG). The individual indication, choice of preparation and dosage are determined exclusively by the treating physician in the course of a personal consultation.
Scientific Overview
The Tool and Its Variants
Botulinum toxin type A is a protein toxin derived from Clostridium botulinum. In highly purified, greatly diluted and standardized form, it has been used therapeutically since the 1980s — initially in neurology for blepharospasm and cervical dystonia, and in aesthetic medicine since 2002.
According to a systematic review (Frevert and Pickett 2018, Drugs in R&D), the approved preparations differ mainly in their neurotoxin complex, specific biological potency and immunogenicity. Clinical efficacy is described in the literature as comparable.
“The quality of the active substance is nearly identical between qualified practitioners. What varies is the outcome — and that comes down to anatomical precision.”
Dr. med. Thomas Ackermann · Specialist in Anesthesiology
Mechanism of Action
How Botulinum Toxin Works — Four Steps
Four Neurotoxin Classes
What Pharmacologically Distinguishes the Preparations
All BoNT-A preparations approved in Europe contain the same 150 kDa neurotoxin. The differences lie in the accompanying matrix, the formulation and the manufacturing process.
| Class | INN and Molecular Weight | Characteristics |
|---|---|---|
| Class I with complexing proteins |
OnabotulinumtoxinA 900 kDa |
The originally developed and longest clinically documented preparation. The neurotoxin is embedded in a complex of non-toxic accompanying proteins. Specific biological potency approximately 137 U/ng neurotoxin (Frevert 2015). Powder for reconstitution. Approved in Germany since 2002 for aesthetic use. |
| Class II smaller complex |
AbobotulinumtoxinA approx. 400 kDa |
Complex-containing formulation with a smaller average molecular weight. Dosed in Speywood units — product-specific and not interchangeable. Specific potency approximately 154 U/ng. Diffusion characteristics are described somewhat differently in the literature. |
| Class III complexing-protein-free |
IncobotulinumtoxinA 150 kDa |
Contains only the neurotoxin itself — complexing proteins are fully removed during manufacturing. Specific potency approximately 227 U/ng, the highest of the classes. Meta-analysis of 5,811 subjects (Fabbri et al. 2017): antibody rates of 0.8 to 1.1 percent versus 3.6 to 7.2 percent for complex-containing formulations. |
| Class IV ready-to-use |
BoNT-A, liquid Ready-to-Use |
The first liquid formulation, approved in Europe since 2021 and in Germany since late 2021. Dosed in Speywood units. No reconstitution required, resulting in batch-standardized preparation. The approval covers treatment of glabellar lines. Long-term clinical experience is naturally more limited. |
“The effect happens in the muscle. The right formulation follows from individual medical judgment.”
Dr. med. Thomas Ackermann · Specialist in Anesthesiology
Evidence Base
Four Studies Provide the Framework
Clinical Relevance
When the Choice of Active Substance Makes a Difference
For many one-time aesthetic treatments, the pharmacological differences are barely noticeable in practice. In certain situations, however, they become decisive.
Long-Term Repeat Treatment
In migraine prophylaxis or frequent aesthetic sessions over years, immunogenicity can become clinically relevant. Secondary treatment failure due to antibodies is documented.
Treatment History
Existing antibody titers from previous therapies can affect the outcome. Taking a history and documenting it is standard practice.
Muscle Mass and Anatomy
Diffusion characteristics and potency kinetics can factor into the choice for very small or very large muscle groups.
Individual Contraindications
Allergies to excipients such as human albumin, or coexisting conditions, can limit the choice.
Patient Information
Possible Effects, Side Effects and Risks
Even a carefully performed treatment with botulinum toxin type A can cause unwanted effects. The following information is drawn from the prescribing information of the approved preparations and from the scientific literature, and does not replace a personal medical consultation.
| Frequency | Possible Unwanted Effects |
|---|---|
| Common more than 1 in 100 |
Temporary pain, redness or swelling at the injection site · Minor bruising in the treated area · Headache or a feeling of pressure in the first few days |
| Uncommon 1 in 100 to 1 in 1,000 |
Temporary asymmetry of facial expression · With forehead treatment, slight drooping of the eyebrow or eyelid (ptosis) — resolves completely · A stiff, mask-like feeling at excessive doses, avoidable through measured dosing |
| Rare fewer than 1 in 1,000 |
Allergic reactions to components of the preparation · Watery or dry eyes with treatments around the eyes · Temporary difficulty swallowing with treatments in the neck area |
Before Treatment
What I Need to Know From You
Please tell me about any existing neuromuscular disorders such as myasthenia gravis, pregnancy or breastfeeding, known allergies to botulinum toxin or excipients, and any ongoing treatment with certain antibiotics, such as aminoglycosides. In these cases, treatment may not be possible or requires particular caution.
What makes sense after treatment.
- For about four hours, do not massage the treated area and do not lie face-down
- For 24 hours, avoid intense physical exertion, sauna and sunbathing
- The full effect develops after seven to fourteen days; any fine-tuning is discussed no earlier than this point
This list is not exhaustive. Complete medical information tailored to your individual situation is provided in a personal consultation before every treatment.
The Next Step
Patient Information Belongs in a Conversation
Which preparation, which dosage and which expectations make sense for you become clear in a personal appointment — with findings and with time. Herzogenaurach, twelve minutes’ drive from Erlangen.
Frequently Asked Questions
What Patients Want to Know
Is there a single “best” botulinum toxin product?
No, it isn’t that simple. According to current studies, the preparations approved in Germany are comparable in clinical efficacy. Differences in pharmacology can be relevant in individual cases. Which preparation is chosen for a specific indication and a specific patient depends on numerous individual factors and is decided in the consultation — not by marketing.
Why aren’t units interchangeable between preparations?
Because units are defined specifically for each preparation, via an LD50 bioassay in a mouse model under manufacturer-specific conditions. One unit of one preparation does not equal one unit of another. Dosing must be individualized for each preparation according to its prescribing information — a central safety topic in medical training.
What are complexing proteins, and why do they matter?
Complexing proteins — neurotoxin-associated proteins, or NAPs for short — are non-toxic accompanying proteins that remain with the neurotoxin in some manufacturing processes. They stabilize the molecule but are not required for its effect. In complexing-protein-free formulations, they are removed. In the literature, they are discussed as one of several possible factors in antibody formation during long-term therapy.
Can neutralizing antibodies affect the treatment’s effect?
Yes, potentially. If the body forms antibodies against the toxin with repeated use, this can lead to secondary treatment failure — the effect diminishes or fails to occur, even though the dose is unchanged. According to the meta-analysis, the overall likelihood is around 2.1 percent, though it varies by formulation and treatment frequency.
How do I find out which preparation is used on me?
Every medical treatment with a prescription-only medicine is preceded by detailed information. You will be told which specific preparation is planned, along with the dosage, the expected effect and possible side effects — in conversation and, where helpful, in writing as well. Transparent information is part of the physician’s duty of care.
Regulatory Status
Approval in Germany
Several BoNT-A preparations are currently approved on the German market under the Medicinal Products Act (Arzneimittelgesetz). All preparations are prescription-only and may be prescribed and administered exclusively by licensed physicians. A named list of approved preparations is publicly available from the Federal Institute for Drugs and Medical Devices (BfArM) and the European Medicines Agency (EMA).
Source note. The studies cited in this article are publicly accessible, peer-reviewed publications in international scientific journals. This article provides general patient information and does not replace individual medical consultation.
Legal notice. This text is an editorial article for patient-oriented information under the physician’s duty to inform pursuant to § 8 of the German Medical Professional Code (MBO-Ä). It contains no product-related advertising within the meaning of § 10 (1) of the German Therapeutic Products Advertising Act (HWG). The mention of pharmaceutical substance classes serves exclusively a scientific, factual presentation within the scope of this information.
Note on applicability. The specific choice of preparation, dosage and indication is made exclusively by the treating physician in the course of a personal consultation, following an individual medical history.
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