Is it ok to take supplements at nights?

Yes for most but...: This depends on which supplements. Many people find b vitamins to be stimulating. Certain herbs and Amino Acids (ginseng, tyrosine) are stimulating as well. Some supplements are relaxing (magnesium, taurine, theanine, tryptophan, holy basil). Many are neutral (vitamin c, vitamin e, zinc). Most supps are ok to take at nite but avoid the ones that might stimulate you.