Many people take metoprolol without major problems, but some side effects can be subtle or mistaken for other conditions. If you’ve recently started metoprolol or had a dose increase, it’s worth being aware of these possibilities.
Common or often-overlooked side effects include:
- Fatigue or low energy – Feeling more tired than usual is one of the most common effects.
- Dizziness or lightheadedness – Especially when standing up quickly, due to lowered blood pressure.
- Slow heart rate (bradycardia) – A slower pulse is expected to some degree, but if it’s very slow or accompanied by fainting or severe dizziness, seek medical attention.
- Cold hands and feet – Reduced circulation can make your extremities feel chilly.
- Sleep changes – Some people report vivid dreams, insomnia, or disturbed sleep.
- Mood changes – Depression or feeling emotionally “flat” has been reported, although the relationship isn’t always clear.
- Reduced exercise tolerance – You may notice you become tired or short of breath more easily during physical activity.
- Sexual side effects – Decreased libido or erectile dysfunction can occur in some people.
- Digestive symptoms – Nausea, diarrhea, constipation, or stomach discomfort may occur.
- Masking low blood sugar symptoms – In people with diabetes, metoprolol can make it harder to notice warning signs of hypoglycemia, such as a rapid heartbeat.
When to contact your healthcare provider
Contact your healthcare provider if you experience:
- Persistent or severe fatigue.
- A resting heart rate that’s unusually low, especially if you have symptoms.
- New or worsening shortness of breath.
- Swelling in the legs or rapid weight gain.
- Fainting or repeated episodes of severe dizziness.
- Significant mood changes or depression.
When to seek emergency care
Seek emergency medical attention if you have:
- Chest pain that is new or worsening.
- Difficulty breathing.
- Fainting.
- Signs of a severe allergic reaction, such as swelling of the face, lips, tongue, or throat, or trouble breathing.
Important: Don’t stop taking metoprolol suddenly unless your healthcare provider tells you to. Abruptly stopping it can cause rebound increases in heart rate and blood pressure and may increase the risk of chest pain or heart attack in some people. If it needs to be discontinued, it’s usually tapered gradually under medical supervision.
