Hello thanks for asking from HCM Effexor is SNRI drug and the drug acts by increasing serotonin and noradrenaline concentration in brain. Simvastatin is lipid lowering drug. It s safe to use amino acid supplements with these drugs but read the constituents before using. Anino acids like tryptophan or tyrosine should better be avoided with Effexor as this may increase the risk of serotonin syndrome which is an emergency. Try to use the supplements in limited amounts and there wouldn t be any harm. Consult your doctor if you have any symptoms like anxiety, restlessness, dizziness, nausea, vomiting etc. Thanks, hope this helps you