The Negative Side Effects of Botox Injections

Botox is the brand name in the United States of a form of bacterial poison called botulinum toxin type A. This substance causes botulism, a poisoning typically found in infected food. As Botox, however, the concentration is both low and purified. It is injected into your muscles in low doses to make those muscles—typically in the face—to relax and be unable to contract. This, the Mayo Clinic reports, makes the skin over those muscles appear smooth and flat, reducing the wrinkles in the area.

Injection Site Problems

Because botulinum toxin type A is introduced into your muscles via a needle, the actual act of the injection can cause you to get a bruise there. The area also may be painful. This can be caused by both the needle itself and the substance, Botox. also states swelling and redness can occur at the site. The muscles that are injected also may become weak or stiff near the site of injection. Classified as non-serious, these side effects should be temporary and disappear in a few days or a week 1. Tell your doctor if they do not.

Toxin Spread

Botulinum toxin type A is a poison, so if it spreads beyond the muscle that is intended, it can cause symptoms that are typical of botulism. These side effects may include difficulty breathing, slurring your speech, swallowing difficulties and weakness in your other muscles 1. These are serious side effects, so report them to your physician immediately 1.


When you first receive your Botox injection, the drug can have the temporary effect of making you anxious. You may feel worried about things you normally wouldn’t be concerned with, and you may not have any reason to feel this way. This is a common side effect and should pass in a few days.

Blurry Vision

Botox also may cause some problems with your vision. Because it is essentially relaxing the muscles in your face, Botox can make it difficult to focus your vision on near or far objects, or both. reports this as a temporary side effect. Your eyes also may become irritated and dry because of the drug.

Cold Symptom Side Effects

Taking the Botox injection also can temporarily induce side effects that are similar to the symptoms of influenza or a common cold 1. For example, you may be congested or have a runny nose. You may get a fever and chills or a cough. Report these to your doctor if they continue beyond a few days.