Wellbutrin (bupropion) typically starts to show some effects within 1 to 2 weeks, especially improvements in sleep, energy, or appetite. However, it usually takes about 4 to 6 weeks to feel more significant benefits in mood and motivation, and up to 6 to 8 weeks to experience the full effect on depressive symptoms. The exact timeline can vary depending on individual factors such as dosage, specific condition being treated, and personal body chemistry.