That's exactly what I think. We are talking about an IPOTETIC risk based on research on rats but there is nothing scientifically demonstrated. If we consider that these supplements have been on the market for at least 20 years and have been used by thousands and thousand of people, it's possibile that no one has ever demonstrated this link? Above all, if there is a link, one would need to know whether serotonin produced by a normal 5htp dose could actually result in damage or if much greater quantities would be needed. The problem is that when talking about this topic all speak with absolute certainty that is not scientifically proven.

If we look at examine.com there is a little paragraph devoted to this issue but it is clarified that this link has not yet been demonstrated: "5.2. Aromatic L-Amino Acid Decarboxylase inhibitors The enzyme dopamine decarboxylase (aromatic L-amino acid decarboxylase) mediates the conversion of 5-HTP into serotonin, and this enzyme is expressed in stomach tissue.[53] Inhibition of this enzyme in the stomach during 5-HTP ingestion is thought to promote the concentration of 5-HTP that reaches neural tissue, which is supported by a study using 100-200mg Carbidopa (pharmaceutical inhibitor) alongside 5-HTP to increase radioactivity of 5-HTP (indicative of neural accumulation) in humans.[54] Green tea catechins (both EGCG and EGC) appear to irreversibly inhibit the enzyme with inactivation values of 868M/min and 1511M/min, respectively, and this inhibition has been noted at 100µM.[55] The combination of supplemental 5-HTP and a dopamine decarboxylase inhibitor is also thought to reduce the risk for cardiovascular complications, as excess serum (but not neural) serotonin is associated with heart valve disease in rats.[56] Due to the accumulation of 5-HTP in neural tissue following the combination[54] it is plausible to assume a reduction in systemic serotonin; this has not been demonstrated yet, however. Pairing supplemental 5-HTP with an inhibitor of dopamine decarboxylase appears to promote accumulation of 5-HTP and subsequently serotonin in the brain, which has been noted in human case studies. This theoretically reduces the risk of heart valve complications (not yet demonstrated)"