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Botox and Science
Have you heard horror stories about people suffering terrible side effects or even dying after receiving Botox treatments? Put your mind at ease as we fact-check these dramatic tales.

What Is Botox?

Botox — also known as Botulinum toxin — is a protein made from a toxin produced by Clostridium botulinum, the bacteria associated with botulism. As an anti-aging treatment, Botox is injected into the facial muscles to smooth away wrinkles, especially in the top portion of the face.

A few different variations of the toxin exist, namely Onabotulinumtoxin A, Abobotulinumtoxin A, and Incobotulinumtoxin A. These are available under a wide variety of brand names, namely:

  • Botox Cosmetic
  • Vistabel
  • Vistabex
  • Botox Vista
  • Dysport
  • Azzalure
  • Xeomin
  • Xeomeen
  • Bocouture

“Botox is FDA approved to reduce the appearance of frown lines and crow’s feet by temporarily paralyzing the muscles,” says New York plastic surgeon and clinical associate professor of surgery Dr. Gregory LaTrenta. “It also has popular off-label uses such as reducing forehead lines, marionette creases around the mouth, fine upper lip lines, and reducing the appearance of bands in the neck.”

As Dr. Latrenta suggests, Botox injections have been “safety approved” for cosmetic purposes. “Since the effects of Botox only last around 3 to 6 months at best, there is complete return of muscle function in those regions of the face that were treated, and no long-lasting side effects,” adds Dr. Latrenta.

Still, to eliminate any bias and give you accurate and proven information, we turned to scientific literature to discover some documented rates for possible side effects.

botox injections
RELATED: Botox Cosmetic Injections: 10 Common Myths Exposed

Can Botox Cause Botulinum Poisoning?

Botulism poisoning, which can occur as a result of food canning and packaging issues, is a life-threatening condition. When it comes to Botox treatments however, there’s really nothing to be concerned about.

People commonly contract botulism by being exposed to large doses of the bacteria through food, water, or soil. There have been no reported cases of people contracting botulism from Botox injections used in professional clinical situations.

Allergan, the makers of Botox, are required by law to detail any known complications or potential complications that could occur following the use of their products, even in extremely rare cases. For this reason, the company warns users of these potential complications, which may affect areas of the body away from the injection site and cause symptoms of botulism:

  • Trouble speaking
  • Loss of strength and muscle weakness all over the body
  • Vision or eye problems
  • Trouble breathing
  • Trouble swallowing

In fact, contracting botulism from Botox is almost unheard of. In the only reported case available, over ten years ago four patients seeing an unlicensed medical physician and using an unlicensed Botox product did contract botulism. The Botox used in this case was not licensed for human use, and only intended for laboratory research. This practice is highly illegal, of course, and is not common by any means. Incidentally, the unlicensed physician involved in this case was subsequently sentenced to prison.

The overriding message here is to never buy Botox off eBay or have an unlicensed person inject you. Always seek out a certified practitioner with adequate training and a proven track record performing this type of procedure.

Botox Fatalities: Is an Overdose Possible?

In 2009, the U.S. Food and Drug Administration issued a warning that the effects of the botulinum toxin may spread from the area of injection to other areas of the body, causing potentially life-threatening swallowing and breathing difficulties.

These symptoms have mostly been reported in children with cerebral palsy being treated with botulinum toxin for muscle spasticity, a use of the drugs that has not been approved by FDA.

Rest assured that no one has ever died from Botox for cosmetic purposes. The amount of neurotoxin administered is measured in units. The estimated lethal dose is approximately 2,500-3,000 units, which obviously would never be administered in clinical practice. Typical doses for clinical application vary from 4 to 25 units for cosmetic purposes, and up to 300 units for therapeutic purposes — muscle spasticity, nerve overactivity, chronic migraine headaches and so forth.

Even at a higher dose of >360 cumulative units within a 3 month period, research has shown that patients undergoing therapeutic treatment for nerve overactivity and lower limb spasticity experienced no life-threatening complications. The most adverse complication shown was general muscle weakness and/or leg pain that subsequently dissipated on its own.

Eye Edema

Swelling around the eye occurs in up to 1.4 percent of people, and up to 3.1 percent in individuals of Asian ethnicity.

Though an edema doesn’t look pretty, it’s not a serious complication. Onset usually occurs within 5 days and resolves itself within 2-4 weeks. The causes of edema are allergic reaction, infection, trauma, or poor venous or lymphatic return to the eye after Botox.

Below is a patient before Botox (A), one week after treatment with significant eye swelling (B), and two weeks later (C), by which time the swelling had almost entirely resolved itself, without any intervention.

Eye Edema
Image: Chang et al. Medicine

Eyelid, Lip or Brow Drooping

Brow, lip or eyelid drooping and blurred vision occur at a rate of 0.8-3.4 percent and are often a consequence of poor injector technique. When administering Botox injections, it’s necessary to keep within certain anatomical margins as the toxin can spread from the point of the injection site to influence surrounding areas. These side effects commonly occur within 2 weeks of treatment and usually resolve themselves within another 2 weeks.

Dr. Latrenta informs that this is one of the reasons to avoid rubbing the area or doing exercise for 4 to 6 hours after Botox treatments. And of course, if you select a highly qualified injector, these side effects are greatly minimized.

Lip Asymmetries and Imbalances of the Lower Face

Studies show these side effects can occur at a slightly higher rate of 6.9 percent.

“I have seen this in patients treated by other providers, and it is usually due to poor technique with injection of the wrong muscles,” says Dr. Bruce Katz, a board-certified dermatologist based in New York City.


Some people experience headaches after Botox injections. Again, this side effect is usually the result of the injector’s technique rather than a consequence of the product itself. If this does occur, it normally dissipates within 24 to 48 hours.

Pain, Swelling and Bruising

Botox is injected into the target area using very small, fine hypodermic needles, and while it doesn’t always occur, bruising can result from the needle trauma to the skin. This usually resolves itself within a few days.

Some medications and supplements should be avoided to reduce the chances of bruising. “Aspirin and nonsteroidal agents, such as Advil and Motrin, should not be taken for 10 days prior to the treatment,” says Dr. Latrenta. Nonsteroidal anti inflammatory drugs, aspirin, ginkgo biloba, St John’s wort, ginseng, and vitamin E should also be avoided. “These can be restarted several days after your Botox treatment,” he adds.

Inversely, beginning oral arnica and/or bromelain on the day of the injection can help avoid bruises. If any bruising does occur, topical arnica can be used on the affected areas. Applying cold packs can also help alleviate any pain, swelling, or bruising.

“The amount and duration of swelling depends on where the Botox injection is performed, as well as individual tolerance. For example, some patients are just more likely to bruise,” says Dr. Katz. “In my experience, swelling is rare, but if it does occur, it goes away in a few hours.”

Botox Treatment

RELATED: 20 Popular Botox Treatment Questions Answered

Looking Fake

“If Botox is overdone, your forehead appearance most certainly can look frozen, shiny and fake,” says Dr. Latrenta. “This may be the desired look for some. However, there are many women who desire a placid look in their forehead and upper face. Before embarking on treatment, it’s always best to discuss the look you want to achieve with your plastic surgeon. I usually advise patients to preserve some motion to avoid a ‘fake’ look.”

Most Common Cause of Complications

A study by the Journal of Aesthetic Plastic Surgery that evaluated 16 clinical trials consisting of a total of 42,405 individuals who had undergone Botox for facial rejuvenation found that adverse events are most commonly caused by injector expertise.

Dr. Katz shares one such experience, saying, “I had a patient who was treated elsewhere that had her left cheek and side of her mouth drooping from poor injection technique. It lasted 4 months, and looked like she was paralyzed on that side.” Dr. Katz reports this is the most extreme side effect he has ever seen.

“People considering Botox should absolutely review the credentials of any doctor or practice they’re thinking about visiting,” says Dr. Katz. “For safety and best results, Botox injections require precision and knowledge of human anatomy. The right provider will take the time to examine your face closely, answer any questions and provide a qualified opinion on whether or not Botox is right for you.”

While side effects can occur in anyone, regardless of age or other health risks, Botox remains overwhelmingly safe. When side effects do occur, these usually resolve themselves in a short period of time. Most importantly, the risk of side effects is dramatically reduced when the procedure is performed by qualified experts. In fact, most doctors admit they rarely see adverse effects other than some slight bruising and swelling.

Who Should Avoid Botox?

Patients with certain medical conditions should not use Botox. Make sure you tell your cosmetic practitioner about any medicines you’re currently taking before you start your Botox treatments, including prescription and nonprescription medicines, vitamins and herbal products. Allergan suggests that you avoid Botox if you have:

  • Allergies to any of the ingredients in Botox
  • Any type of skin condition where you intend to be injected
  • Urinary tract infection or urinary incontinence

Speak with your doctor before receiving Botox injections if you suffer from a disease that affects your muscles and nerves (such as Lou Gehrig’s disease), if you have chronic breathing problems, if you have had surgery on your face, or if you plan to undergo surgery in the near future.


  • Carruthers A, et al. OnabotulinumtoxinA for Treatment of Moderate to Severe Crow’s Feet Lines: A Review. Aesthetic surgery journal. 2016;36(5):591-7.
  • Sundaram H, et al. Global Aesthetics Consensus: Botulinum Toxin Type A—Evidence-Based Review, Emerging Concepts, and Consensus Recommendations for Aesthetic Use, Including Updates on Complications. Plastic and Reconstructive Surgery. 2016;137(3):518e-29e.
  • Chang Y-S, et al. Nonallergic Eyelid Edema After Botulinum Toxin Type A Injection: Case Report and Review of Literature. Maatouk. I, ed. Medicine. 2015;94(38):e1610.
  • Nuanthaisong U, et al. Incidence of adverse events after high doses of onabotulinumtoxinA for multiple indications. Urology. 2014;84(5):1044-8.
  • Dayan SH. Complications from toxins and fillers in the dermatology clinic: recognition, prevention, and treatment. Facial plastic surgery clinics of North America. 2013;21(4):663-73.
  • Frampton JE, Easthope SE. Botulinum toxin A (Botox Cosmetic): a review of its use in the treatment of glabellar frown lines. American journal of clinical dermatology. 2003;4(10):709-25.

Updated, September 2017

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About The Author

Articles by

Jedha Dening is a contributing health and beauty writer for Zwivel. She specializes in crafting compelling words for B2B & B2C health companies and publications worldwide.