Common (1 in 10 people or more)
The most common Zyban side effect is difficulty sleeping.
Other common side effects include:
- anxiety,
- tremors,
- stomach pain,
- irritability,
- depression,
- lack of concentration,
- headaches and dizziness,
- nausea and vomiting,
- constipation,
- dry mouth,
- fever,
- sweating,
- skin irritation,
- and itching.
These side effects should improve over the first week or two of taking the medication.
Uncommon (1 in 100 people or less)
Less common side effects of taking bupropion-based medications include:
- tinnitus (ringing in the ears),
- confusion,
- hot flushes,
- problems with vision,
- increased blood pressure,
- raised heart rate,
- loss of appetite,
- loss of strength,
- and chest pain.
Rare (1 in 1000 people)
Rare side effects include:
- coordination issues,
- palpitations,
- feeling faint,
- anaphylaxis (allergic reaction),
- loss of memory,
- increased urination,
- increased or decreased skin sensitivity,
- changes in blood sugar levels,
- and hallucinations.
Very rare (less than 1 in 1000 people)
Incredibly rare side effects of bupropion include:
- feeling restless,
- aggressive,
- paranoia,
- delusions
- and urinary incontinence.
Unknown
Due to the lack of data, it is currently unknown if Zyban can cause harm to fetuses. However, it is not advised to take bupropion (the active ingredient in Zyban) during pregnancy.

