Not working less well. Not wearing off sooner. Nothing at all — and switching to Dysport didn't help either, because it's the same protein. That's the situation this treatment exists for.
Botox, Dysport, Xeomin, and Jeuveau are all botulinum toxin type A. If you've developed antibodies to type A, none of them will work — switching brands changes nothing. Myobloc is type B, a structurally different protein that type A antibodies don't neutralise. It has a faster onset, a shorter duration, and stings more going in. For someone getting nothing at all, that's usually a fair trade.
I developed Botox resistance myself. I know what it's like to stop responding to something that used to work — and I use Myobloc. When I tell a patient this works, it isn't something I read in a study.
— Dr. Amir Mortazavi, MD · Founder, Plump Medical SpaThis is the part worth reading first, because most patients who think they've become resistant haven't.
True antibody-mediated resistance is uncommon in cosmetic use, where doses are relatively low. It's better recognised in therapeutic use — cervical dystonia, spasticity — where much larger doses are given more frequently.
Far more often, one of these is happening instead:
Every one of those is cheaper and simpler to fix than resistance. Which is why the consultation starts by ruling them out — and why some patients who arrive asking for Myobloc leave with a properly dosed type A treatment instead.
No reduction in movement at all, at an adequate dose, on more than one occasion, ideally across more than one type A brand.
Wearing off at eight weeks instead of twelve. Weaker than it used to be. Working in one area but not another.
The distinction matters because it determines the answer. Diminished response is usually a dosing conversation. Absent response, repeatedly, at an appropriate dose, is a different problem.
This is the single most useful fact on the page, and it's why patients spend years and considerable money getting nowhere.
Botox, Dysport, Xeomin, and Jeuveau are all botulinum toxin type A. They differ in formulation, accessory proteins, and unit conversion — but the active protein is the same. Antibodies that neutralise one neutralise all of them.
So the standard progression — Botox stopped working, try Dysport, that didn't work either, try Xeomin — isn't three attempts. In true resistance it's the same attempt three times.
Myobloc is type B. Different protein, different structure, and it binds a different target in the neurotransmitter release process. Type A antibodies don't recognise it.
Duration is generally shorter. Where type A commonly gives three to four months, type B is typically reported in a shorter range. That varies by patient, area, and dose — but expect more frequent treatment, not less.
The injection stings. The solution has a lower pH. Topical numbing helps and most patients find it manageable, but it isn't the same experience as Botox.
Dry mouth is the most commonly reported side effect, and occurs more often than with type A. It relates to effects on autonomic nerve endings and is usually temporary.
None of that matters much to someone currently getting no result at all. But it should be understood before treatment rather than discovered after.
Myobloc is FDA-approved for cervical dystonia and chronic sialorrhea. Cosmetic use is off-label — prescribed by a physician for an indication outside the approved labelling.
Off-label prescribing is legal and routine throughout medicine, particularly where approved options have failed. Most aesthetic neurotoxin use beyond the glabella is off-label, including masseter and neck treatment.
It's disclosed here because you should know it, not because it's a problem.
Possibly. Antibody formation is recognised with type B as with type A, and there's no third toxin type available if it happens.
That's the argument for the smallest effective dose at the longest workable interval rather than treating aggressively or frequently. Higher cumulative exposure is generally associated with greater antibody risk.
It's also a reason not to use Myobloc in patients who don't need it.
Most people who come in convinced they're resistant turn out to have been under-dosed for years, and that's a better outcome — type A lasts longer and hurts less. But the ones who genuinely are resistant have usually been told there's nothing more to try, which isn't true. Having been on both sides of this, I'd rather sort out which situation someone is in than sell them the more interesting answer.
How do I know if I have true Botox resistance?
True resistance means complete absence of response — no reduction in muscle movement at all — following an adequately dosed injection by an experienced injector, on more than one occasion, and ideally across more than one type A brand. Results that wear off sooner than they used to, or that are weaker than expected, are generally not resistance. Those are usually dosing, technique, or expectation issues, and they are considerably more common.
Why doesn't switching from Botox to Dysport help?
Because they are the same toxin type. Botox, Dysport, Xeomin, and Jeuveau are all botulinum toxin type A. Antibodies that neutralise one will neutralise the others, regardless of brand or formulation. Switching between type A products in true resistance does not restore response — which is why patients frequently spend years and considerable money cycling through brands with no result.
What is Myobloc and how is it different?
Myobloc is rimabotulinumtoxinB, the only FDA-approved botulinum toxin type B available in the United States. It is a structurally different protein from type A, so antibodies to type A do not neutralise it. It acts at the same nerve-muscle junction but binds a different protein in the release process.
How long does Myobloc last compared to Botox?
Generally shorter. Type A commonly gives three to four months in cosmetic use, while type B is often reported in a shorter range, though this varies by patient, area, and dose. This is a genuine trade-off and should be understood before treatment. For a patient getting nothing at all from type A, a shorter duration is usually an acceptable exchange — but it is not equivalent.
What are the side effects of Myobloc?
Dry mouth is the most commonly reported side effect and occurs more frequently with type B than with type A, related to effects on autonomic nerve endings. Injection is also more uncomfortable, since the solution has a lower pH and stings during administration. Other effects are similar to type A, including bruising, headache, and the possibility of unintended spread to nearby muscles.
Is Myobloc FDA-approved for cosmetic use?
Myobloc is FDA-approved for cervical dystonia and chronic sialorrhea. Cosmetic use is off-label, meaning it is prescribed by a physician for an indication outside the approved labelling. Off-label prescribing is legal and common throughout medicine, particularly where approved options have failed, but patients should understand the distinction and it is disclosed before treatment.
Can I develop resistance to Myobloc as well?
It is possible. Antibody formation is a recognised phenomenon with type B as with type A. This is a reason to use the smallest effective dose and to avoid unnecessarily frequent treatment, since higher cumulative exposure is generally associated with greater antibody risk.
Is Botox resistance common?
True antibody-mediated resistance is uncommon in cosmetic use, where doses are relatively low. It is better recognised in therapeutic use, where much larger doses are given at more frequent intervals. Most patients who believe they have become resistant are actually experiencing under-dosing, a change in injector or technique, or a shift in what they expect from treatment — all of which are more easily addressed.
Do you treat patients from outside Orange County?
Yes. Because few practices offer type B for resistance cases, patients travel from across Southern California. A consultation begins with a detailed review of prior treatment history, and it is worth bringing whatever records you have of products, doses, and dates.
They're the most useful thing you can arrive with. If under-dosing explains it, that's the cheaper fix — and if it doesn't, there's an option nobody told you about.
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(949) 568-7544 — info@plumpmedicalspa.com
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