Some potential negative effects of Botox treatment include:

1. Bruising: Botox is injected with a needle, which can cause bruising at the injection site.
2. Headache: Some people may experience a headache after getting Botox.
3. Drooping eyelids: If Botox is injected too close to the eye muscles, it can cause temporary drooping of the eyelids.
4. Dry mouth: In rare cases, Botox treatment can cause dry mouth.
5. Allergic reactions: Although rare, some people may have an allergic reaction to the Botox injection.
6. Numbness: The injection site may feel numb for a short period of time after the treatment.
7. Weakness: In rare cases, Botox treatment can cause weakness in the muscles that were injected.

It is important to discuss any potential negative effects with a healthcare provider before getting Botox treatment.