Speech-language pathologist (SLPs) may work with patients who receive botulinum toxin (BoNT) injections, such as for voice disorders , cervical dystonia, and chronic migraine (Padda & Tadi, 2023; Yale Medicine, n.d.). BoNT injections are also used off-label for conditions such as post-stroke pain, trigeminal neuralgia, and spinal cord injury (Padda & Tadi, 2023). In addition, BoNT injections can result in conditions that may lead people to seek a speech therapy evaluation. This article will discuss the possible side effects of BoNT, with a focus on what SLPs should know.
I’m interviewing Megan McCue, a fellow speech-language pathologist, about her life-altering experience after a single round of cosmetic injections to treat wrinkles around her eyes. Her side effects included difficulty swallowing, brain fog, ear nerve damage, and significant hair loss, among other symptoms.
Megan’s written two books about her experience, a memoir and a factual review of the history of Botox® and the possible side effects of BoNT injections. She emailed me a free PDF of the factual review, which I read before approaching her to do this written interview. I would like to raise awareness about the possible side effects of botulinum toxin injections, both for the general consumer but especially for speech-language pathologists.
Free DIRECT download: What SLPs should know about botulinum toxin (cheat sheet). (Email subscribers get free access to all the resources in the Free Subscription Library.)
Outline:
- Megan, tell us a little about yourself.
- What happened the day you saw your doctor for cosmetic injections?
- What changes did you notice in your health after the injections?
- How did your doctor respond to your symptoms?
- How did your symptoms impact your life?
- Why did you take a deep dive into the research on botulism and BoNT?
- What are possible side effects of botulinum toxin?
- Was your experience a rare occurrence?
- Why do you think the possible side effects of BoNT aren’t more widely known?
- What should SLPs be aware of when evaluating a new patient?
- What should an SLP do if their patient may be experiencing botulism?
- Which compensatory strategies did you find helpful?
- Where can people find you or your books?
- Related Eat, Speak, & Think posts.
- Selected references.
Megan, tell us a little about yourself
I’m Megan McCue, a home health SLP based in California. I work for a large hospital system and see patients in their homes after hospital stays. My areas of interest include aphasia, cognitive rehabilitation and dementia support, and voice disorders resulting from Parkinson’s Disease (I am LSVT LOUD certified). When I’m not working, I enjoy spending time with my family, playing my piano, and reading.
What happened the day you saw your doctor for cosmetic injections?
On July 9, 2024, I received 12 units of Xeomin® injections for the first time ever for my “crow’s feet” or wrinkles around my eyes. Xeomin is a brand of botulinum toxin injections, which are typically known by the most common brand, Botox® Cosmetic. I’ll refer to this class of injections as BoNT.
Before being injected, I asked my doctor, “Have any of your patients ever had side effects from Botox?” She said no, but that I might experience some pain at the injection site.
I was not given any written information about adverse effects from BoNT injections, or the “Black Box Warning” that is on all BoNT products, which includes brands such as Xeomin®, Botox®, and others.
What changes did you notice in your health after the injections?
Where to begin? I developed immediate neurological symptoms upon injection near my right eye. My brain became incredibly foggy, I was having a hard time concentrating on anything in the room. I also began to feel head pressure.
I reported my symptoms to my doctor right after she injected me, but she didn’t say anything. I called her office about two hours later to tell her that I had started feeling dizzy and nauseous, and that I was having extreme brain fog. She told me that I was “anxious” and that I should go drink a cup of tea.
The next morning, my eyes were bloodshot. I again called her office and was told I had “allergies”. Over the course of the next week, I began experiencing frightening anxiety attacks that would last for hours, as if my body was in a state of fight or flight. These would come every couple of days out of nowhere, whether I was sitting at home calmly, or driving on the freeway to go see a patient for work.
Over the course of the 3-4 weeks post injections, the following additional symptoms unfolded:
- Neck muscle fatigue and weakness that would cause my head to feel heavy and tilt.
- Severe dry mouth resulting in difficulty swallowing solids.
- Globus sensations that would last for hours after meals.
- 20-pound weight loss due to lack of appetite and swallowing difficulties.
- Insomnia.
- Continued brain fog.
- Debilitating fatigue, forcing me onto disability for 2.5 months.
- Hair loss.
- Ear nerve damage causing constant sensation of clogged ears, as well as occasional tinnitus.
I also experienced occasional episodes of shortness of breath and involuntary arrest of my diaphragmatic muscle for a few seconds at a time. That was by far the scariest symptom!
How did your doctor respond to your symptoms?
For the first month or two, I had no idea what was happening to my body. I was trying to ignore the symptoms I was having, as I suspected they were a result of the BoNT injections, but was too scared to Google them.
Two months after injections, after being told I was “just fine” by nearly every ER doctor I interacted with, I finally dug into the Xeomin clinical trials and medical literature and realized I was experiencing what is called “mild botulism”.
I reached back out to my injecting doctor with a list of my symptoms, and asked her to please report my symptoms to the FDA Adverse Event Reporting System (FAERS) database, which tracks adverse effects of drugs.
My injecting doctor told me that she believed I needed psychiatric care, but that she would let her Xeomin marketing rep know about my symptoms. She refused to report my symptoms to the FDA.
I was not offered any advice for my symptoms, and I was rushed out of her medical office by her staff. Unfortunately, there is no treatment for botulism symptoms resulting from BoNT except time.
How did your symptoms impact your life?
I was unable to work for 2.5 months straight. I could not even care for my children most days, as I was in a constant state of whole body fatigue and mental exhaustion.
About six weeks after my injections, when my dry mouth and globus sensations became worse, I had to consume a mostly liquid diet (IDDSI Levels 1, 2, and 3). Even pureed foods would give me globus for hours after and would cause residue in my pharynx and esophagus.
This was confirmed on my MBSS (swallow test) – and was likely due to lack of saliva and mucous, as well as my esophageal muscles not contracting properly. I had to remain on this liquid diet for about 7 weeks. Thank goodness I had the training I do as an SLP- we made many shakes and soups!
My saliva production increased at around the 7 week mark, making it possible for me to enjoy solid foods again. Unfortunately, even at 7 months out, my saliva production is still not what it used to be – dry mouth is a botulism symptom that can last for years.
My cognitive symptoms came and went for about 3-5 months. These included brain fog, slow processing speed, and short term memory impairment. My husband was convinced my IQ had dropped at least 30 points! Once those completely cleared, I was able to function and go back to work.
Why did you take a deep dive into the research on botulism and BoNT?
When I was initially sick, I was in pure survival mode. I had no mental energy or motivation to read anything. I did, however, watch all 4 seasons of Emily in Paris in a month :).
Once I began to heal and come out of the brain fog, I was determined to figure out what had happened to me. So about 5 months after my injections, I began learning as much as I could about BoNT adverse effects.
I am curious by nature and did not like the fact that I had been gaslit and ignored by almost every medical professional I had interacted with while I was sick. My primary care doctor is the only medical professional who listened to me and believed me.
I joined a large support group for BoNT-injured folks (over 40,000 members) and learned that my situation was not unique. There were, unfortunately, many other sufferers out there who were experiencing these adverse effects and being ignored by their doctors or told that BoNT could not possibly cause these symptoms.
In that group, I met a researcher who had worked alongside Sharla Helton, the doctor who sued Botox’s makers (Allergan) for her life-altering injuries in 2010. I became fast friends with this botulism researcher and author, J.A. Talkington, and she pointed me in the direction of various research articles and books. Her book, Recognizing Botulism*, gave me a better understanding of how BoNT can cause symptoms of mild, moderate, or severe botulism.
*This is an Amazon affiliate link. As an Amazon associate, I may
earn a small commission on qualifying purchases. There is no extra
charge to you, and it will help keep Eat, Speak, & Think
sustainable.
What are possible side effects of botulinum toxin?
All BoNT product inserts (Botox®, Dysport®, Xeomin®, Jeuveau®, etc) include what is called a “Black Box Warning”. It warns consumers that BoNT can spread from the injection site and “produce symptoms consistent with botulinum toxin effects.”
This is a euphemistic way of saying that BoNT injections can cause botulism, and it happens when the toxin spreads either through the bloodstream, through muscle tissue, or along nerves into the central nervous system (a process called “retrograde axonal transport”).
Botulism can occur in mild, moderate, or severe forms, which was a fact that early 20th century physicians knew based on case studies of food-borne botulism victims. Many doctors today are unfamiliar with mild botulism, which has been shown to occur in about 75% of “iatrogenic” botulism cases.
Mild botulism includes symptoms like dizziness, blurry vision, anxiety, fatigue, muscle weakness, insomnia, dry eyes and mouth, and difficulty swallowing that does not require a feeding tube (such as globus).
Moderate botulism is considered any of the above symptoms, plus the need for a feeding tube.
Severe botulism cases will require mechanical ventilation when the diaphragm is weakened/paralyzed.
All of these symptoms are listed in the BoNT package insert as occurring in clinical trials patients and/or in post-marketing data (FAERS reports).
Nobody knows how long these adverse effects can last, because manufacturers are not required to conduct clinical trials beyond 12 weeks. Many people who develop systemic toxin spread can suffer from these symptoms on and off for a year or more. Sadly, in the case of severe botulism, some symptoms can last decades.
There have been over 2,000 reported deaths following BoNT injections, and we know this is likely a very small percentage of actual deaths due to the persistent problem of under-reporting (many injecting doctors, like my own, do not believe Botox can injure patients). The most common causes of death after BoNT injections are respiratory failure, cardiac arrest, and aspiration pneumonia.
Was your experience a rare occurrence?
This is the million dollar question. Nobody knows exactly how often adverse effects are happening. Many of these symptoms go unreported, as people may not realize they are experiencing botulism symptoms. Many injecting doctors are often unfamiliar with Botox’s adverse effects, and thus may not report them when patients present with subjective complaints.
Per Botox’s own package insert, the risks of various adverse effects differs based on the injection site. For example, consider cervical dystonia patients. These patients receive injections in the neck, and the risk of dysphagia with each injection ranges from 15-25%, due to localized toxin spread into the pharyngeal muscles. On the other hand, patients receiving BoNT in the forehead for cosmetic purposes or migraines have a smaller risk of developing dysphagia.
From everything I’ve researched and read, the risk of systemic toxin spread (into the bloodstream and/or brain) seems to be anywhere from 0.5 to 5% per injection. Beyond the manufacturer’s clinical trial data, we don’t have great placebo-controlled trials that are independently authored on BoNT adverse effects.
BoNT, once in the bloodstream, can end up anywhere, so people will present with a wide variety of botulism symptoms. Some will be more serious than others (think: difficulty breathing vs dry eyes). The less serious botulism symptoms may be written off as mere “side effects”, when they are in fact direct effects of the toxin spreading in the body.
Until there is more awareness about the condition, as well as objective research involving large numbers of patients, it will be difficult to know how often iatrogenic botulism is occurring in the real world.
Why do you think the possible side effects of BoNT aren’t more widely known?
Another really good question. There are a few factors at play. The first, and most important one is, many injecting doctors are under the impression that botulism from BoNT is not possible. They are often trained on the safety and efficacy of BoNT from pharmaceutical representatives.
Despite the product coming with a Black Box Warning, and over 46,000 serious (life-threatening or disabling) adverse events having been reported to the FDA post-BoNT injections (again, likely a very small percentage of actual events), there is simply not enough awareness in the medical field about mild and moderate botulism symptoms.
These “milder” symptoms may not present as typical food-borne botulism, which usually includes descending flaccid paralysis and respiratory failure. Because BoNT acts on our neurotransmitters (it blocks acetylcholine transmission, and even other neurotransmitters like glutamate and GABA in the CNS), there is no reliable objective test for presence of botulinum toxin in the body.
The toxin, once in the bloodstream, is taken up into our nervous system rapidly, typically within a few hours. The standard tests for detecting botulinum toxin in the bloodstream are not accurate after 2-3 days post exposure.
What often happens is patients fall ill, report their symptoms to their doctors (or even end up in the ER), and are told there is nothing wrong with them. Many botulism patients will have completely normal CBCs, CMPs, EKGs, etc. I didn’t have any abnormal lab readings throughout my first few months with botulism.
Beyond all of these challenges, we have pharmaceutical industry influence. Who’s paying for the Super Bowl commercials? And your nightly news show’s commercials? BoNT. It is a powerful, $11 billion industry with a vested interest in casting their products in the most favorable light possible.
What should SLPs be aware of when evaluating a new patient?
I would love to see a future where every SLP is asking patients who present with idiopathic speech, swallowing, and/or respiratory impairments about prior BoNT use in the past 6-12 months.
Some of the most common adverse effects of Botox include dysphagia, dysphonia, dysarthria, xerostomia, and dyspnea. These are conditions that SLPs commonly see on their caseload.
Many of our patients receive BoNT injections for muscle spasticity, migraines, excessive saliva, and even overactive bladder. The medical uses for BoNT are growing rapidly, and I have been amazed at how many of my patients are regularly receiving injections now that I have begun asking them about BoNT use.
In just the first few months after I returned to work, I had two patients who were presenting with botulism symptoms (severe dry mouth, globus sensations, dizziness, blurry vision) in the weeks after Botox injections. Both of them told me I was the first person who had asked about their use of Botox.
What should an SLP do if their patient may be experiencing botulism?
Since many neurologists and other injecting doctors are unaware of all of the adverse effects that can result from BoNT injections, this can be tricky. I want to stress that in 2025, there is not enough medical research or awareness about iatrogenic botulism resulting from Botox injections.
I think as SLPs, we can serve as a resource and encourage our patients to become informed about all of their medications’ side effects, including BoNT injections. Drugs.com is a great resource that lists many different adverse effects of Botox, and I have encouraged a few of my patients to visit that website to learn more.
Patients can report their symptoms to their primary care physician, their injecting physician, the makers of the BoNT, and the FDA. Once they know the name of the BoNT they received, they can obtain the insert from their medical provider or from the internet. The insert will include instructions for how to report suspected adverse reactions. The FDA can be reached at 800-FDA-1088 or via their MedWatch online reporting program.
We could also speak with our patient’s doctors if we suspect that iatrogenic botulism may be occurring and use that as an opportunity to raise awareness about the condition.
There is an antitoxin that can stop the progression of symptoms, but treatment of botulism is time sensitive and the antitoxin must be dispatched by the CDC. The antitoxin can cause serious side effects, as well. The antitoxin can’t reverse damage that was already caused. (Ni & Brady, 2023)
Which compensatory strategies did you find helpful?
Nothing really helped with the cognition other than writing things down on post-its around the house, as well as setting alarms on my phone to help me remember events, etc. Thankfully my cognitive symptoms cleared relatively quickly – they only lasted about 6-8 weeks, and would “come and go” throughout the week.
There was a supplement I took a few times that helped as well, it’s called “Huperzine A”. Some people with dementia and myasthenia gravis take it, because it can increase acetylcholine transmission in the brain/body.
Energy levels – my husband took over almost all of the childcare and household duties. This was the only way I survived, as I was either on the couch or in bed resting for 6-8 hours a day initially.
Swallowing – XyliMelts and the Biotene products were amazing for the dry mouth. I also chewed gum and sucked on peppermint drops for extra saliva. Other than that I had to modify food and “chase” everything with water.
Where can people find you or your books?
Both of my books (Me Tox Pretty* and Notox*) are available on Amazon. Me Tox Pretty is a short memoir of my first five months with botulism (you won’t believe my MBSS story!). Notox covers the history of Botox and the possible adverse effects of all BoNT injections.
Readers can also go to my website www.meganmccue.com to read my blog, where I discuss all things iatrogenic botulism. I would be happy to hear from any SLPs who want more information on this condition. They can reach me at metoxpretty @ gmail.com.
*This is an Amazon affiliate link. As an Amazon associate, I may
earn a small commission on qualifying purchases. There is no extra
charge to you, and it will help keep Eat, Speak, & Think
sustainable.
Related Eat, Speak, & Think posts
- How to use the Spoon Theory to manage fatigue.
- 10 ideas for the speech therapy patient we’re not sure how to help.
- Take the guesswork out of thickening liquids with the IDDSI flow test.
- Interview – Meet the Nice Speech Lady.
- Interview with Allison Toepperwein: Overcoming Parkinson’s disease. (American Ninja Warrior competitor!)
Selected references
Check out Megan’s book Notox for a more substantial reference list, but here are some key references for the information in this interview:
- Botox product insert: https://www.rxabbvie.com/pdf/botox-cosmetic_pi.pdf?mibextid=2JQ9oc
- Coté, T. R., Mohan, A. K., Polder, J. A., Walton, M. K., & Braun, M. M. (2005). Botulinum toxin type A injections: adverse events reported to the US Food and Drug Administration in therapeutic and cosmetic cases. Journal of the American Academy of Dermatology, 53(3), 407–415. https://doi.org/10.1016/j.jaad.2005.06.011
- Hsieh, S. (2011, May 9). ‘Ground-breaking’ Botox case results in $212M jury verdict. New Orleans CityBusiness. https://neworleanscitybusiness.com/blog/2011/05/09/%E2%80%98ground-breaking-botox-case-results-in-212-million-jury-verdict/
- Hristova, A.H., Joseph, L.N., Sathe, S.A. & Wade, J.B. (2012), Severe Nervous System Complications After Botulinum Type A Therapy: Three Case Reports With Reviews of FDA-Reported Nervous System Adverse Effects. PM&R, 4: 613-623. https://doi.org/10.1016/j.pmrj.2012.04.016
- McCue, M. (2025). Me tox pretty: A story of iatrogenic botulism and the ugly side of cosmetic injections. Independently published.
- McCue, M. (2025). Notox: The shocking truth about cosmetic injections. Independently published.
- Ni, S. A., & Brady, M. F. (2023, September 4). Botulism antitoxin. In StatPearls. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK534807/
- Padda, I. S., & Tadi, P. (2023, November 6). Botulinum toxin. In StatPearls. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK557387/. Accessed 2/15/2025.
- Xeomin product insert: https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/125360s073lbl.pdf
- Yale Medicine. (n.d.). Botox and soft tissue fillers. Yale Medicine. Retrieved February 15, 2025, from https://www.yalemedicine.org/conditions/botox-and-soft-tissue-fillers
Free DIRECT download: What SLPs should know about botulinum toxin (cheat sheet). (Email subscribers get free access to all the resources in the Free Subscription Library.)
Featured image by Tara Winstead from Pexels, found on Canva.com.
Lisa earned her M.A. in Speech-Language Pathology from the University of Maryland, College Park and her M.A. in Linguistics from the University of California, San Diego.
She participated in research studies with the National Institute on Deafness and other Communication Disorders (NIDCD) and the University of Maryland in the areas of aphasia, Parkinson’s Disease, epilepsy, and fluency disorders.
Lisa has been working as a medical speech-language pathologist since 2008. She has a strong passion for evidence-based assessment and therapy, having earned five ASHA Awards for Professional Participation in Continuing Education.
She launched EatSpeakThink.com in June 2018 to help other clinicians be more successful working in home health, as well as to provide strategies and resources to people living with problems eating, speaking, or thinking.
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