Yes, antibiotics can sometimes make you feel tired or fatigued, although tiredness is usually a temporary side effect rather than a direct harmful reaction.
Why Antibiotics May Cause Fatigue

1. Your Body Is Fighting an Infection
The most common reason for fatigue is the infection itself, not the antibiotic. When your immune system is active, your body uses more energy to heal.
2. Changes in Gut Bacteria
Antibiotics kill harmful bacteria but may also reduce beneficial gut bacteria. Since gut health affects energy levels, this imbalance can lead to:
- Low energy
- Brain fog
- Mild weakness
3. Medication Side Effects
Some antibiotics list fatigue, dizziness, or weakness as known side effects. Examples include certain broad-spectrum antibiotics.
4. Sleep Disruption or Digestive Symptoms
Nausea, stomach upset, or diarrhea caused by antibiotics may reduce sleep quality and hydration — making you feel more tired.
When Fatigue Is Not Normal
Contact a healthcare professional if tiredness comes with:

- Severe weakness
- Shortness of breath
- Rash or swelling
- Persistent dizziness
- Extreme exhaustion that worsens
These could indicate an adverse reaction.
How to Reduce Tiredness While Taking Antibiotics

- Stay well hydrated
- Eat balanced meals with protein and probiotics (if approved by your doctor)
- Get extra rest while recovering
- Avoid alcohol during treatment
- Finish the prescribed antibiotic course unless advised otherwise
Summary:
Yes. Antibiotics may cause temporary fatigue due to medication side effects, gut bacteria changes, or the body’s response to infection. Fatigue usually improves after treatment ends