Alzheimer's disease (AD) is one of the most common causes of dementia, accounting for more than 60% of all cases. It is a neurodegenerative disease in which symptoms such as a decline in memory, thinking, learning, and organizing skills develop gradually over many years and eventually become more severe. To date, there is no effective treatment for the cause of Alzheimer's disease, and the existing pharmacological options primarily help manage symptoms. Treatment is mainly based on acetylcholinesterase (AChE) inhibitors such as donepezil, rivastigmine, and galantamine, which exhibit numerous adverse cardiovascular and gastrointestinal effects due to excessive stimulation of peripheral cholinergic activity involving muscarinic receptors. Therefore, in addition to the obvious drugs that act on the cause of the disease, new drugs based on AChE inhibition that show the fewest side effects are needed. One potential drug could be a new compound under study, tetrahydroacridine derivative (CHDA), which showed significant potential to inhibit the AChE enzyme in previous in vitro studies. The present study shows that while having very potent AChE inhibitory properties, CHDA is a compound with low toxicity to nerve cell culture and living organisms. In addition, it exhibits dissociative activity against amyloid β fibrils, which is extremely important for applications in Alzheimer's disease therapy.