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Therapeutic Botox: Should we paralyze misbehaving muscle?

 •  • by Paul Ingraham
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B&W photo of a syringe.

There are many types of unwanted muscle contractions — cramps and twitches are just the tip of the iceberg — and many mysteries and myths about them. A reader asked me if it was feasible to treat a persistent twitch with Botox, and I sure do relate to that desire: I have endured such a twitch myself, several months of being constantly kicked in the shoulder blade by a strong latissimus dorsi twitch. I nearly lost my mind.

The botulinum toxin actually paralyzes muscle. So that seems promising. How can a paralyzed muscle twitch? Or cause any other kind of trouble? This logic has led to many therapeutic applications of Botox. But it’s a complicated stew of pros and cons.

Some Botox basics

The brand name “Botox” is a contraction of “botulinum toxin,” a potent neurotoxin that paralyzes muscle. Clostridium botulinum is the bacteria that produces that toxin as as a metabolic waste product, and it is among the most poisonous substances in the world. Yikes! Think of that bacteria like a microscopic frog, exuding deadly slime through its skin. It works by blocking the neurotransmitter acetylcholine — the messenger molecule that flows from nerve endings to muscle cells to initiate muscle contraction. The toxin clogs the outlet for the release of acetylcholine molecule from the pre-synaptic membrane.

In theory, Botox has the potential to be helpful for any medical condition that is powered by spasm — not just wrinkles. Botox can even shut down some glands, which is why it is also used to treat things like excessive sweating or salivating (strange but true).

Botox caveats

Unfortunately, therapeutic Botox is not always a great idea in practice, and wise prescription and delivery requires clinical expertise. There are several reasons why Botox might not be an easy win…

  • It may not be worth the risks of using a deadly neurotoxin to “nuke” a relatively minor problem. (Not to minimize the suffering that rogue muscle contractions can cause, and certainly some cases are not minor by any reckoning. But most are much less serious than truly dire medical problems, and a treatment with significant risks is probably not a great idea.) If you’re wondering if this dangerous poison ever gets into the wrong tissue and kills… yes, it does. Botox disasters are rare, but they do happen, and much more often with therapeutic botox than cosmetic, because of deeper injections of larger doses into more sensitive anatomy, and for more experimental reasons.1 And, of course, less dire side effects also happen.
  • It’s often not clear how much muscle contraction is the actual mechanism of suffering (e.g. for migraine and headache, where there’s evidence that Botox can be helpful, but also evidence that it can cause headache2). Like most drugs, it doesn’t always work… and it might actually seem to backfire, causing a short term surge in muscle tone, and/or some degree of longer-lasting local or even systemic inflammation — which feels like a very raw deal (especially if no specific therapeutic effect is also achieved, which is often the case). A fascinating recent case study of hypersensitivity to Botox following Covid vaccination highlights the fact that the immune system can react to Botox … and overreact to it!3 (And that was a reaction to a low-dose cosmetic treatment.)
  • Even when it’s fairly clear that spasm is the problem, stopping it with Botox may not be practical. Sometimes the muscle in question is technically difficult to inject safely, often because it is small and/or adjacent to delicate tissues. Or it may not be practical to paralyze muscles because there’s just too much muscle involved, and/or you need that muscle for other purposes… like walking or breathing!
  • Even when it works — even in the very best-case scenario — it’s rarely a permanent solution. If the problem persists, the treatment has to be repeated.

Botox applications, both good ones … and maybe not so good

Despite all those concerns, there are cases where it probably does make sense to try. For instance, Botox is used to treat spasticity,4 especially if it’s severe, or caused by a serious disease (such that side effects and safety issues are the lesser of evils, sometimes by far). More examples of therapeutic Botox where its potential probably justifies the risks:

  • Dysphonia (difficulty speaking) in Parkinson’s disease, and also excessive salivation in those patients (which Botox may help by paralyzing the glands and/or by improving swallowing). Ironically, Botox can also make swallowing worse.
  • Painful spasticity in multiple sclerosis and the strangely (but aptly) named stiff-person syndrome (a rare neurological disease, in the headlines in late 2022 because of Celine Dion’s diagnosis) .
  • Contractures — severe shortening from chronic spasticity — occurs in many diseases, like cerebral palsy, muscular dystrophy, or arthrogryposis. Isolated dystonias like torticollis (wry neck) can also cause contracture, and Botox can prevent progression.
  • The peculiar condition known informally known as “no-burp” (Retrograde Cricopharyngeal Dysfunction). A little paralysis of the cricopharyngeus muscle, and — ta da! — the burps come back! Here’s a charming little website about it (really).
  • Urinary incontinence. Bladder a bit too squeezy? Paralyze it a bit!

Therapeutic Botox is technical and complicated, and the debate continues on whether and how it should be used, especially for relatively minor musculoskeletal pain. Eye twitches are a great example of a condition in the Botox grey zone: it can make a lot of sense for severe and chronic cases with known pathological cause, but it would be reckless to inject Botox if the twitching is more likely caused by, say, exhaustion or a thyroid storm.

Many Botox providers advertise treatment for issues like neck and back pain, headache, jaw clenching, frozen shoulder, and trigger points — and all of these are much fuzzier targets. One reader commented that “every pain specialist I spoke to recommended Botox because they said they didn’t get results with steroid or anaesthetic injections.” I think Botox is probably used a little too freely and simplistically as a substitute for steroids or anaesthetic.

This post is an excerpt from a much larger article all about unwanted muscle contractions.


  1. Witmanowski H, Błochowiak K. The whole truth about botulinum toxin - a review. Postepy Dermatol Alergol. 2020 Dec;37(6):853–861. PubMed 33603602 ❐ PainSci Bibliography 51239 ❐ “The frequency of serious side effects is 33 times higher for therapeutic than for cosmetic cases.”
  2. Mullaaziz D, Kaptanoğlu A. Is botulinum toxin a cause or a cure for headaches? J Cosmet Dermatol. 2022 Feb;21(2):595–599. PubMed 34897957 ❐ (Witmanowski et al also discuss this.)
  3. Guo X, Li T, Wang Y, Jin X. Sub-acute hypersensitive reaction to botulinum toxin type A following Covid-19 vaccination: Case report and literature review. Medicine (Baltimore). 2021 Dec;100(49):e27787. PubMed 34889230 ❐ PainSci Bibliography 51236 ❐
  4. Sun LC, Chen R, Fu C, et al. Efficacy and Safety of Botulinum Toxin Type A for Limb Spasticity after Stroke: A Meta-Analysis of Randomized Controlled Trials. Biomed Res Int. 2019;2019:8329306. PubMed 31080830 ❐ PainSci Bibliography 52066 ❐