Can You Take Leucine with Melatonin?

There is no evidence that taking leucine and melatonin together causes any adverse effects or interactions. Research on melatonin and amino acids like leucine does not indicate any significant interactions. You can likely take them as part of your supplement routine without concern. No known biochemical mechanism of interaction between leucine, an amino acid important for protein synthesis, and melatonin, a hormone regulating sleep-wake cycles. Their metabolic pathways do not appear to intersect in a way that would cause an interaction.