Backgrounds: Memory and emotion are especially vulnerable to psychiatric disorders such as post-traumatic stress disorder (PTSD). which is linked to disruptions in serotonin (5-HT) metabolism. Over 90% of the 5-HT precursor tryptophan (Trp) is metabolized via the Trp-kynurenine (KYN) metabolic pathway. which generates a variety of bioactive molecules. https://www.mariameetsanna.com/product-category/anti-frizz-shampoo/