Much better than expected. Have been taking C4 for the last 6 months and recently broke my headphones so decided to give this a go since it came with free headphones and it far exceeded by expectations. You don't get that huge initial surge of energy but it does give you prolonged energy and fatigue is rarely a problem for me anymore, headphones are pretty good as well, not the best quality but can't complain since they were free. Would definitely recommend