Is Botox Safe? Side Effects, the Boxed Warning and Who Should Avoid It

Is Botox safe? For healthy adults treated with the FDA-approved product at labeled doses, the research says yes, with side effects that are usually mild and temporary. In this guide I explain what the large safety studies found, what the FDA boxed warning means, which side effects are common and which are rare, and who should not be treated. I also cover the risk that has grown in recent years: counterfeit Botox.

What the safety research shows

Botox Cosmetic has been studied in thousands of patients, and the pooled data show a low rate of serious problems at cosmetic doses. It was the first neurotoxin the FDA approved for an aesthetic use, in 2002, and it is now approved for frown lines, crow’s feet, forehead lines and, since 2024, neck (platysma) bands.

Two large analyses of the original trial data are the most useful evidence. In a 2009 meta-analysis in the Journal of the American Academy of Dermatology, Mitchell Brin and colleagues pooled 1,678 participants treated for frown lines and crow’s feet. The overall rate of side effects was not significantly different from placebo, no serious adverse events were judged to be caused by treatment, and no one had weakness away from the injection site. A larger 2024 analysis in JAAD International pooled 5,298 participants from 18 trials. Serious adverse events occurred in 1.6% of people given Botox and 1.3% given placebo, and the authors found no new side effects.

Those trials excluded people with serious medical conditions and followed patients for a limited time, and both analyses note those limits. That is one reason a proper medical history matters before treatment.

The FDA boxed warning, explained

All botulinum toxin products carry a boxed warning that the toxin’s effect can spread from the injection site and cause botulism-like symptoms. The Botox Cosmetic prescribing information lists those symptoms, including trouble swallowing, speaking or breathing and general muscle weakness, and says they can appear hours to weeks after injection. It is a serious warning, and it is explained before treatment.

The label also puts it in context. It says the risk is probably greatest in children treated for spasticity and in adults with underlying conditions that make them vulnerable. For cosmetic use, the label states that there have been no definitive serious reports of distant spread at the labeled doses for frown lines (20 units) and crow’s feet (24 units). If you ever have trouble swallowing, speaking or breathing after an injection, the label says to get medical care right away, and so do I.

Common and uncommon side effects

Most side effects of cosmetic Botox are local, mild and wear off. The trial rates in the label and the 2009 meta-analysis give a realistic picture:

Side effect	How often in trials	What it means
Pain or bruising at injection points	Facial pain in 1% of frown line trial patients	Local and short-lived
Headache	9% with forehead treatment (5% with placebo)	Usually the first day or two
Eyelid drooping (ptosis)	3% in frown line trials, 2% in forehead trials	Temporary; wears off as the toxin does
Brow drooping or heaviness	2% in forehead trials	Related to dose and placement in the forehead
Eyelid “tight” or “heavy” feeling	2.5% vs 0.3% placebo (2009 meta-analysis)	Mild; became less common with repeat treatment
Dry eye	Reported near the eye muscles	Tell us if your eyes feel dry or gritty

The 2009 analysis found that the most frequent treatment-related effects became less common as patients had more treatment cycles.

Who should not have Botox, or needs extra care

A short list of people should not be treated, and a few more need a careful conversation first. From the label:

• Allergy to any botulinum toxinA known hypersensitivity to Botox, Dysport, Xeomin or similar products rules out treatment.
• Infection at the injection siteAn active skin infection where we would inject means waiting until it has cleared.
• Nerve and muscle disordersThe label calls for extra caution with myasthenia gravis, Lambert-Eaton syndrome, amyotrophic lateral sclerosis (ALS) and peripheral motor neuropathies, because the effects of Botox can be stronger.
• Swallowing or breathing problemsPeople with pre-existing difficulty may be more susceptible to these complications.
• Certain medicinesAminoglycoside antibiotics, muscle relaxants and anticholinergic drugs can add to the effect. Our post on Botox and antibiotics covers this in detail.
• Pregnancy and breastfeedingThe label has no adequate human data. Because there is not enough safety data, the usual advice is to wait until after pregnancy and breastfeeding, so tell us if you are pregnant, trying to conceive or nursing. See Botox and pregnancy.

The real risk: counterfeit and unlicensed Botox

The most serious recent Botox injuries in the US came from fake or mishandled products, not from FDA-approved Botox used correctly. In 2024 the CDC investigated 17 people in 9 states who had harmful reactions after injections, 13 of whom were hospitalized. Some received counterfeit or unverified products, some were injected by people who did not follow state licensing rules, and some products had been bought from large online marketplaces. The CDC continued to receive similar reports later that year, including people who injected themselves.

The CDC’s advice is simple: ask whether your injector is licensed and trained, and whether the product is FDA-approved and comes from an authorized supplier. At KORA every treatment is performed by me or by one of our nurse practitioners. With any provider, it is reasonable to ask to see the product before treatment.

What causes a “bad Botox” result

A frozen look, uneven brows or a heavy forehead is almost always a matter of dose and placement, not a property of Botox itself. Too many units in the forehead, toxin placed too close to the brow, or a plan that ignores how your face moves can all produce it. These results are temporary and wear off with the toxin, and some can be softened at a follow-up. Our post on Spock eyebrows after Botox explains one of the most common ones.

What Botox costs at KORA

Prices come from our current price list. Your plan and total are confirmed at a complimentary consultation before anything begins.

Talk through your questions first

If you have a health condition or take regular medicines, bring a list to your consultation. Read more about Botox at KORA, how many units of Botox you may need, and what not to do after Botox. Our clinic is on the Scottsdale and Paradise Valley border.