Basically scientists found that agonising the AT4 receptor improves memory, and Harding&Wright managed to find a small molecule agonist (dihexa) capable of crossing the brain blood barrier (BBB). . While more experimentation is needed to prove the benefits of the drug, current evidence from personal users notes the drug’s ability to improve their thinking and cognitive abilities with regular use. The pharmacokinetic barrier has recently been overcome with the synthesis of the orally active, blood-brain barrier–permeable analog N-hexanoic-tyrosine-isoleucine-( 6) aminohexanoic amide (dihexa).