Metoprolol is a commonly prescribed beta-blocker used for conditions including high blood pressure, angina and certain heart problems. It works partly by slowing the heart rate and reducing the workload on the heart.
Like any medication, metoprolol can cause side effects. Many are mild and improve as the body adjusts, but some symptoms deserve medical attention—particularly if they are new, severe or getting worse.
Important: The image accompanying this article shows a bottle labeled amlodipine, not metoprolol. Amlodipine and metoprolol are different medications, so the information below applies specifically to metoprolol.
1. Unusual Tiredness
Feeling unusually tired or lacking energy is one of the recognized side effects of metoprolol.
Because the medicine slows the heart rate and reduces the heart’s workload, some people may feel more fatigued, particularly when they first begin treatment. nhs.uk
If severe fatigue persists or interferes with daily activities, talk with your doctor rather than stopping the medication yourself.
2. Dizziness or Lightheadedness
Metoprolol can cause dizziness or lightheadedness, particularly when blood pressure or heart rate becomes lower.
If you feel dizzy, sit or lie down until the sensation passes and avoid driving or operating machinery while affected. nhs.uk
Repeated dizziness or fainting should be discussed with a healthcare professional.
3. Slow Heart Rate
Because metoprolol is designed to slow the heart rate, a slower pulse can occur.
However, a heart rate that becomes excessively slow—especially when accompanied by weakness, dizziness, fainting or breathing difficulties—requires medical attention. Bradycardia is listed among the recognized adverse reactions. DailyMed
4. Low Blood Pressure
Metoprolol can lower blood pressure, which may contribute to dizziness, weakness or feeling faint.
This can be particularly noticeable when standing up quickly.
If you repeatedly feel lightheaded or nearly faint, your healthcare professional may need to check your blood pressure and heart rate.
5. Cold Hands and Feet
Some people taking metoprolol notice that their hands or feet feel unusually cold.
The NHS lists cold hands and feet among common side effects and explains that beta-blockers can affect blood flow to the extremities. nhs.uk
Persistent or severe circulation symptoms should be reported to your doctor.
6. Digestive Problems
Metoprolol can cause digestive symptoms such as diarrhea, and some people may experience other stomach-related discomfort.
MedlinePlus lists diarrhea among possible side effects, while the prescribing information also identifies it as a reported adverse reaction. MedlinePlus
If diarrhea is severe or persistent, speak with a healthcare professional.
7. Sleep or Mood Changes
Some people report changes in sleep or mood while taking beta-blockers.
Depression is included among reported adverse reactions in the prescribing information for metoprolol tartrate. DailyMed
Any significant or persistent change in mood should be discussed with your healthcare provider.
8. Shortness of Breath
Shortness of breath is important because it can have several possible causes.
It is listed among possible adverse reactions to metoprolol, but breathing difficulties can also indicate an underlying heart or lung problem. MedlinePlus
Seek prompt medical attention if new or worsening shortness of breath occurs, particularly with swelling, rapid weight gain, chest discomfort or worsening exercise tolerance.
9. Swelling of the Legs or Feet
Swelling in the ankles, feet or lower legs is a symptom that should not simply be ignored.
MedlinePlus lists swelling of the hands, feet, ankles or lower legs and unexplained weight gain among symptoms requiring medical attention. MedlinePlus
This is especially important in someone taking metoprolol for a heart condition.
10. Metoprolol Can Mask Some Warning Signs of Low Blood Sugar
People with diabetes should know that beta-blockers such as metoprolol can mask some symptoms of hypoglycemia, according to the prescribing information. DailyMed
That doesn’t mean people with diabetes cannot take metoprolol, but blood-glucose monitoring and individualized medical advice are important.
When Is Metoprolol an Emergency?
Seek urgent medical attention for symptoms such as:
Severe difficulty breathing
Fainting
New or worsening chest pain
Severe wheezing or chest tightness
Rapid, pounding or irregular heartbeat
Significant swelling accompanied by breathing problems
These symptoms can sometimes indicate a serious reaction or worsening heart or lung problems. nhs.uk
Never Stop Metoprolol Suddenly
One of the most important points is that metoprolol should not usually be stopped abruptly without medical guidance.
Sudden withdrawal can worsen certain heart conditions and may increase the risk of serious cardiac problems. DailyMed
If side effects are bothering you, contact your doctor. The dose may need adjustment, or another treatment may be considered.
The Bottom Line
Metoprolol is an important medication for many people, and experiencing a side effect does not necessarily mean the medication is unsafe for you.
Common problems include tiredness, dizziness, cold hands or feet and digestive symptoms, while symptoms such as fainting, significant swelling, breathing difficulties or abnormal heart rhythms deserve prompt medical attention. nhs.uk
And remember: the medication shown in the supplied image is amlodipine, not metoprolol.
Have you ever noticed a change after starting a blood-pressure or heart medication? Tell us in the comments 👇
