Why does Botox spread from injection site? Under-diluted, too much, or treatments too close together?

Doctor Answers 9

Botox spread typically limited to 1cm. Here's how.

Botox is a liquid solution injected under the skin. As it gets absorbed it can spread about 1 cm or less than half an inch. Deep massage can increase the spreading distance, but it's still a short distance. When diluted, more fluid is injected per unit of Botox, giving it more potential to spread in the tissues. All of these factors together contribute to spread from the injection site. 

It's important to seek out a trained injector who standardizes the dilution, so the amount injected is consistent. When in doubt, ask your injector about the concentration they use. I encourage my patients to ask as many questions as they need to feel knowledgeable and safe. 

San Diego Facial Plastic Surgeon
5.0 out of 5 stars 10 reviews

Botox Spread of Injection

Typically Botox can diffuse about one centimeter from the treatment sites.  The "black box" warning warns of distant effects of Botox potentially.  Please consult an expert for the best results.  Best, Dr. Green

Michele S. Green, MD
New York Dermatologist
5.0 out of 5 stars 71 reviews

Botox spread from injection site

Typically botox can migrate or spread about 1 cm from its injection site. It is normal to have some spreading as without this happening it would not work to paralyze the muscle to result in the diminishing of the wrinkle lines that are being treated. Treatments too close together can cause some additional migration if it is difficult for the injector to determine the muscle movement. Under dilution or too concentrated really has little effect on the migration; however, the volume of product injected can cause a greater migration of product to other muscles.

Scott Trimas, MD
Jacksonville Facial Plastic Surgeon
5.0 out of 5 stars 20 reviews

Why does Botox spread from injection site? Under-diluted, too much, or treatments too close together?

Thank you for your question. Botox typically spreads 1 cm from the injection site. If you are concerned, speak with your chosen physican injector.


Martin Jugenburg, MD
Toronto Plastic Surgeon
4.9 out of 5 stars 449 reviews

Botox spreading after injection

Botox will spread normally about 1cm. If it is reconstituted with more saline, then it will likely spread a bit more. It does not relate to treatments being too close together. Also, if you rub the area in the first day (e.g. deep facial massage), you can spread it more.

Benjamin Barankin, MD, FRCPC
Toronto Dermatologic Surgeon
4.9 out of 5 stars 47 reviews

Botox spread

Distant spread of Botox effect through the body is very rare, even when used in much higher doses for non-cosmetic purposes. Local spread, affecting muscles not intended, and causing such things as brow and lid droop, may be caused by placement and dose. Diluting a lot, which means the dose is in a larger volume of liquid, may also increase risk. On the other hand, the injection technique may not be the cause - the patient may rub the area affecting distribution, for example, and there is significant variation in individual anatomy, which can modify nerve and muscle position and affect outcome.

Nicole Kafka, MD
New York General Surgeon
1.0 out of 5 stars 1 review

Why does Botox spread from injection site? Under-diluted, too much, or treatments too close together?

Hello Georgiafitz,

It is rare for Botox to spread from the injection site.  Acts that increase the risk of it causing a droopy eyelid or eyebrow is by injecting too close to those areas or with too many units of Botox injected close to those areas.  As far as distant spread that has been reported but is usually seen with very high doses injected for non cosmetic purposes.  Failure to follow post treatment recommendations can also increase the risk of spread (such as exercise or massaging the areas the same day as the treatment.  

The best way to get the result your are going for is to have an experienced physician injector.  When it comes to Botox you aren't paying for the Botox but rather the result.  I'd recommend you consult with one of the core injectors (facial plastic surgeon, plastic surgeon, oculoplastic surgeon, and dermatologist).  

I hope this helps and good luck.

William Marshall Guy, MD
The Woodlands Facial Plastic Surgeon
5.0 out of 5 stars 27 reviews

Botox and Spread

Botox can spread from the injection site despite injection technique. I suggest you speak to your physician if you are concerned.  Best, Dr. Emer.

Jason Emer, MD
Los Angeles Dermatologic Surgeon
4.9 out of 5 stars 188 reviews

Why does Botox spread from injection site? Under-diluted, too much, or treatments too close together?

Thank you for your excellent question.  Botox comes to your injector's office as a dehydrated powder that becomes reconstituted with normal saline.  The injector has discretion in how much normal saline is used in order to control the degree of dilution.  Because the units of botox determine effectiveness of treatment the dilution is important to know because the more saline used, the more fluid injected for the same number of units and the greater spread of the fluid from the site of injection, possibly leading to complications.  Hope this helps. 

Nelson Castillo, MD
Atlanta Plastic Surgeon
5.0 out of 5 stars 54 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.