Botox helps treat and prevent certain conditions by blocking nerve signals to specific muscles. However, using Botox may lead to certain neurological side effects.
Botox is widely used for both medical and cosmetic purposes and has approval for a variety of uses. These include preventing migraines, managing muscle spasms, and reducing the appearance of fine lines and wrinkles.
Although Botox is generally considered safe and effective, it may cause neurological side effects in some people. This article explores these potential side effects, how they may occur, and steps you can take to help reduce your risk.

Botox works by temporarily blocking nerve signals to specific muscles. This helps reduce symptoms such as muscle spasms and wrinkles. However, the use of Botox can sometimes result in neurological side effects.
Neurological side effects are symptoms or conditions that affect your nervous system, which includes your brain, your spinal cord, and the nerves that communicate with the rest of your body.
The type of neurological side effects that may occur with Botox often depends on the area where it’s injected and the dose used. The likelihood of these side effects may also be greater when Botox is used for conditions requiring larger doses or injected near sensitive areas.
Possible neurological side effects of Botox include:
- Eye problems: These may include blurred vision or ptosis (drooping eyelids), particularly when Botox is injected near your eyes.
- Dysphagia (difficulty swallowing): Dysphagia is more likely to occur when Botox is injected near your neck or throat.
- Headache: Although Botox is used to prevent migraine, some people have reported headaches from Botox, particularly after it’s used for cosmetic purposes.
- Dizziness: Although less common, dizziness can occur after a Botox injection and may temporarily affect activities such as driving.
- Facial paralysis: Botox is used cosmetically to relax facial muscles and reduce wrinkles. However, unintended facial paralysis may occur when Botox is injected into the facial area for other purposes, such as migraine prevention.
In rare cases, the effects of Botox may spread beyond the targeted muscle and lead to more serious neurological side effects. This risk is highlighted in the boxed warning for Botox. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For more details, see the “Boxed warning” section at the beginning of this article.
It may not be possible to entirely prevent neurological side effects from Botox, but you can take certain steps to help reduce your risk.
The following are some key tips to help prevent neurological side effects from Botox:
- Choose an experienced doctor or other healthcare professional: Receiving Botox from a qualified healthcare professional increases the likelihood of proper injection technique. This can greatly reduce the risk of side effects, including neurological ones.
- Start with the proper dose: Discuss dosing with your doctor before treatment. They can help you understand whether your dose may increase the risk of neurological side effects.
- Watch for early signs: Pay close attention to symptoms such as drooping eyelids, difficulty swallowing, dizziness, and unexpected muscle weakness. Reporting these to your doctor early can help address potential issues before they worsen.
- Prepare for future injections: If you experience neurological side effects, talk with your doctor. They may adjust your dosage, change the injection sites, or modify how often you receive treatments. These changes can help reduce the likelihood of neurological side effects in the future.
If you have neurological side effects or other unusual symptoms after receiving Botox, let your doctor know right away. Doing so can help you manage side effects and ensure that your treatment remains safe and effective.
When used appropriately, Botox is unlikely to cause long-term neurological side effects. Most side effects are temporary and resolve as the effects of Botox wear off. This typically occurs within 3 to 4 months after each injection.
Long-term use of Botox may carry some non-neurological risks. For example, repeated injections can cause targeted muscles to weaken or shrink over time. This happens because the muscles have gone long periods of time without use. In rare cases, some people also develop proteins that work against the activity of Botox after long-term use.
It’s important to discuss the potential long-term risks of Botox with the doctor or other healthcare professional who is giving your Botox injections. They can tell you more about how long neurological side effects may last.
There’s no scientific evidence that Botox causes cancer. Concerns about cancer risk may stem from the fact that Botox is a type of drug called a neurotoxin. However, Botox is a highly purified form of neurotoxin that’s given in small doses.
Although Botox works by blocking nerve signals to specific muscles, its effects are temporary and do not suggest any link to cancer development.
If you have any concerns about the effects of Botox on your health, including its cancer risk, talk with your doctor.
Botox is a widely used treatment and is generally considered safe. Although Botox may cause neurological side effects, these are typically mild and temporary. More serious complications may occur in rare cases, but proper use and proper injection technique can greatly reduce this risk.
If you have unexpected symptoms during Botox treatment, talk with the doctor or other healthcare professional who gave you the injections. They can help ensure that Botox remains a safe and effective treatment option for you.