Botox Safely: Side Effects and When Symptoms Are an Emergency
Part of: Botox
How Botox works on wrinkles, common and rare side effects, what to do after injection, and why counterfeit Botox or injections outside a clinic are a real danger.
Medical Aesthetics · 2 min read · August 22, 2026
Written and medically reviewed by Dr. Yousef Abo Zarad · German board-certified dermatologist · Last reviewed: September 2026
Key takeaways
- Botox temporarily relaxes specific facial muscles, softening expression lines.
- Results usually last 3 to 4 months, sometimes longer.
- Common effects are mild: a bruise for about a week, and slight redness or soreness.
- Trouble swallowing, breathing or speaking after injection is an emergency.
- Counterfeit Botox, or Botox injected in homes and salons, has caused real poisoning cases.
How does Botox work?
Botox (botulinum toxin) is injected in very small amounts into specific muscles, temporarily relaxing them. When the muscle relaxes, the wrinkles its movement causes soften, such as forehead lines, frown lines and crow's feet.
How long do results last?
Results appear within days and usually last 3 to 4 months, sometimes longer. The muscle then gradually starts moving again, and injections can be repeated.
What are the side effects?
| Effect | How common | Duration |
|---|---|---|
| Bruising at the injection site | Common | About a week |
| Mild swelling, redness or soreness | Common | Temporary |
| Headache | Uncommon | Temporary |
| A droopy brow or eyelid from weakness in a nearby muscle | Rare | Temporary |
| Serious complications | Very rare | Need immediate care |
When are symptoms an emergency?
Rarely, the toxin's effect can spread beyond the injection site, hours to weeks after injection. The official prescribing information warns that trouble swallowing and breathing can be life-threatening.
- Trouble swallowing or breathing.
- General muscle weakness.
- Double or blurred vision, or drooping eyelids.
- Trouble speaking or a change in voice.
Any of these symptoms after injection needs emergency medical care right away.
What to do after injection
- Don't rub or press the injection sites, and don't press on makeup.
- Avoid strenuous activity for two hours so the Botox doesn't move to other muscles.
The danger of counterfeit Botox and non-clinic injections
In 2024, the U.S. Centers for Disease Control and Prevention reported poisoning cases after counterfeit Botox or injections by unlicensed people in homes or spas. Symptoms included double vision, drooping eyelids, and trouble swallowing and breathing.
Buying Botox online, or having injections at parties, salons or homes, exposes you to counterfeit, contaminated or badly stored products and can cause lasting complications.
Only have injections from a qualified doctor, in a clinic, with a product of known origin.
Common questions
- Is Botox permanent? No; it usually lasts 3 to 4 months.
- Will it freeze my face? The right dose and placement soften lines while keeping natural expressions.
- Does it have medical uses? Yes, including treating excessive sweating.
Key numbers
- About a week: how long a bruise lasts.
- 2 hours: avoid strenuous exercise and pressing on the area after injection.
Medical Evidence
Keep reading on this topic
- For how long the effect lasts, read how long Botox lasts.
- For when it starts working, read when Botox starts working.
- For injection areas and a natural result, see the Botox face map.