Yes, amoxicillin can make you feel tired or fatigued, although tiredness is not one of the most common side effects. The feeling of tiredness while taking amoxicillin may be due to both the medication itself and your body's natural response to fighting an infection. The medication can affect energy levels through changes in gut bacteria, nutrient absorption, and mild stress on liver function. Meanwhile, the infection being treated requires your immune system to use extra energy, which also contributes to fatigue. If tiredness persists or worsens, it's important to consult a healthcare provider.