Source Naturls always amazes by the quality of its products. This product was very well produced, I have already tested their melatonin and now I have taken a good amount of the 5 HTP Tryptophan, and I can say that it is EXCELLENT !!! great quality!! I did not feel any side effects, on the contrary, it helped me in my anxiety, it improved my sleep, and it made me want to eat all day, super recommend !!!!!! I also bought to help in the fight against depression, and I can say that I have been feeling better every day ..