I'm running to lose fat now. What do I need to add? Ask a fitness expert for advice?
If you don't need supplements, I suggest you take a proper rest, recover and even overeat for a day, otherwise your body will get more and more tired. Supplements are of little use, but you can buy glutamine and branched-chain amino acids if you have money. The former promotes recovery and the latter relieves fatigue, but tonic is a tonic after all.