Concerns over botox injection sites

I have been considering Botox for some fine lines on my forehead, but recently came across a University of Wisconsin-Madison study that discovered Botox not only works on neurons at the site of injection but may travel to more distant sites. Having a toxin as powerful as Botox travel through the neural network seems quite concerning to me. As highly trained plastic surgeons, do this concern you? Should I be concerned about this study as a person considering Botox?

Here's the study for reference: 


M, 49, New York

In the field of cosmetic surgery, Botox is in the top spot with no other procedure even coming close to its popularity. According to the American Society of Plastic Surgeons (ASPS), over 7 million Botox injections were performed in the US in 2017.

While this is an interesting study, it has to be evaluated in the context of a pharmaceutical that has has been subjected to extensive clinical testing over the past 20 years. Botox is by far the most popular minimally-invasive procedure in the world.

As multiple clinical studies have indicated, the incidence of adverse reactions to botulinum toxin A is very low and the side effects are reversible, transient, and generally localized. But as with all medications, adverse reactions are possible.

There are also some special cases to be aware of: If you have any known allergies to eggs you should avoid Botox because the botulinum toxin preparation contains an albumin base. If you suffer from pre-diagnosed neuromuscular disorders such as myasthenia gravis or Lambert-Eaton syndrome you’ll require special monitoring when receiving Botox treatment. For most patients, however, outside of a few special categories, the risks of adverse reactions are very low.

While I think the study you linked to is interesting and raises some legitimate questions, the amount of clinical and statistical evidence we have already strongly suggests that Botox is a safe and effective treatment with a low incidence of serious adverse side effects. If there are some potentially serious effects that do exist as a result of botulinum toxin spreading from the injection site, we already have enough experience to suggest their incidence is very low.

Negative results in the hands of a skilled and experienced plastic surgeon are rare. I advise you to seek out a plastic surgeon who has a long history of satisfied patients.

The 2016 UW-Madison study about botulinum toxin follows on the heels of a 2009 warning from the FDA that botulinum toxin can spread from the injection site to other areas throughout the body.

Reports of muscle weakness and difficulty breathing are certainly cause for concern. When doctors inject Botox or Dysport into the frontalis muscles in the forehead, or the orbicularis oculi muscle (which causes crow's feet), we expect the effects to be strictly local.

If those effects are in fact systemic, then more study is certainly required.

It's important to remember that all pharmaceutical products have potential side effects, but the incidence of serious adverse events associated with Botox treatment is well-documented and low.

Botox is the most popular non-invasive cosmetic procedure in the world, with millions of procedures performed annually.

The risks of mild pain or bruising at the injection site -- or the occasionally reported headaches or flu-like symptoms -- far outweigh the risks of botulinum toxin traveling along newly discovered neural pathways. In the unlikely event that you experience muscle weakness or difficulty swallowing, I advise you to contact your physician immediately.

I suggest you visit a plastic surgeon who has extensive experience and a proven track record with Botox injections. For best results and patient safety, always remember to only consult with board-certified plastic surgeons or dermatologists.

Prior to the UW-Madison study you refer to doctors understood that the botulinum toxin in Botox injections ‘stayed put’ at the injection site, restricting only local muscle activity.

As you may know, the reason Botox does such a wonderful job preventing the formation of crow's feet, frown lines, glabellar, and other forehead lines is that botulinum toxin impedes neurological signals across the neuromuscular junction by inhibiting an important neurotransmitter called acetylcholine.

When normal muscle contractions of the facial muscles are inhibited, the facial expressions which cause facial wrinkles are inhibited along with them.

As discussed in the 2016 UW-Madison study, an additional neural pathway which allows the botulinum neurotoxin to travel away from the neurons controlling local neuromuscular transmission and move throughout the neural network has been discovered. Except what this potentially distant spread of botulinum toxin actually means, we still don't know for sure.

It's important to remember that there’s always been some potential for unwanted migration after botulinum toxin injections. In most cases this drift is the result of either poor injection technique or choice of injection site.

While this latest study raises some important questions, we have to remember that Allergan received approval for botulinum toxin type A (onabotulinumtoxinA) back in 2002, and its efficacy and adverse effects have been carefully studied ever since.

Today Botox injections are the most popular cosmetic procedure in the world, with millions of treatments performed annually. Botox is FDA-approved for the treatment of multiple conditions, including muscle spasms, blepharospasm, cervical dystonia, chronic migraines, urinary incontinence and others.

While I think this study certainly raises some concerns and opens avenues for additional testing, adverse results from Botox are very rare when in the hands of an experienced injector.

Excellent question, this is a very interesting and excellent article out of UW-Madison. The field is definitely still in its infancy and we are learning more and more. The effect of botox remains localized to the area it is injected. There are not reports for example of patients being injected in their forehead and having difficulty swallowing following the procedure to the best of my knowledge. The toxin enters the neuron or adjacent neurons to elicit the effect of temporarily inhibiting that neural pathway, or neuro-muscular junction. There is a very large number of these channels in the vicinity of the injection therefore creating the desired effect of weakening the muscle contraction of the target. This in turn shows less lines in the overlying skin that is attached to the treated underlying contracting muscle. Botox has a many different uses. I think the main point is to be sure to be treated by a medical professional with training in injectables and neurotoxins, and be clear on what your physician is looking to improve with the medication.

Hope this was helpful.

Good Luck!

That UW Madison study did raise some eyebrows. The potential for botulinum toxin spreading throughout the body via a separate neural route is somewhat concerning. The understanding among scientists has always been that Botox activity is localized to the neurons at the injection site, with a small chance of "Botox drift" to neighboring neurons.

The discovery of a second pathway enabling the toxin molecules to move to other neurons raises the possibility of broader systemic effects extending well beyond the intended localized ones.

The FDA has been watching Botox closely for many years. After approval for cosmetic uses in 2002, the FDA was concerned enough to issue a follow-up "Risk Evaluation and Mitigation Strategy" in 2009. This advisement addressed the distant spread of the botulinum toxin throughout the body, although you need to keep in mind that the FDA’s concerns in 2009 were in respect to specific classes of patients who received above average doses of Botox.

To answer your question of whether you should be worried about everyday cosmetic uses of Botox, last year in the United States over 7 million injections of botulinum toxin were performed. It is by far the most popular clinical cosmetic procedure in the world. We may not know exactly what the effects of this newly discovered neural channel are, but we do know that serious adverse events associated with Botox are very rare.

Botox is an extremely effective option for reducing the appearance of facial lines and wrinkles while slowing the development of new ones. When injected by a board-certified plastic surgeon the chance of experiencing any serious side effects are highly unlikely.