Alzheimer's disease (AD) is a degenerative neurological condition characterized by cognitive decline, memory loss, and impaired daily functioning. A key feature of AD is the accumulation of amyloid-beta (Aβ) plaques, which initiate a series of pathological events, including neuroinflammation, synaptic dysfunction, tau pathology, oxidative stress, impaired protein clearance, mitochondrial dysfunction, and disrupted calcium homeostasis. Aβ is generated through the cleavage of the amyloid precursor protein (APP) via two pathways: the non-amyloidogenic pathway, which reduces Aβ production and has neuroprotective effects, and the amyloidogenic pathway, which leads to the production of toxic Aβ peptides, such as Aβ40 and Aβ42, contributing to neurodegeneration. The review explores the multifaceted role of Aβ in AD, examining both its beneficial and detrimental effects. Aβ has been found to exhibit antioxidant, neuroprotective, and memory-boosting properties under certain conditions. For instance, Aβ can act as an antioxidant by binding transition metals and reducing their participation in oxidative damage. It also demonstrates neuroprotective effects, such as protecting against oxidative stress and promoting neuronal survival and differentiation. Additionally, Aβ has been shown to enhance long-term potentiation (LTP) and improve memory retention, particularly through interactions with α7-nicotinic acetylcholine receptors. However, Aβ also plays a crucial role in the progression of AD. The accumulation of Aβ, particularly Aβ42, leads to the formation of amyloid plaques, which disrupt the blood-brain barrier (BBB) and contribute to neuroinflammation and synaptic dysfunction. Aβ oligomers, in particular, are highly toxic and contribute to neuronal damage and cell death. They interfere with NMDA receptors, disrupt calcium homeostasis, and induce oxidative stress, leading to synaptic impairment and cognitive decline. The review also discusses the interaction between Aβ and other factors, such as proteases like insulin-degrading enzyme (IDE), neprilysin, and cathepsin B, which play roles in Aβ metabolism and clearance. Additionally, the sequence alterations in Aβ, such as the conversion of aspartate to isospartate, can increase Aβ aggregation and toxicity. Overall, understanding the dual nature of Aβ and its complex interactions is crucial for developing effective therapeutic strategies to target Aβ metabolism, aggregation, and clearance, aiming to mitigate the detrimental consequences of AD.Alzheimer's disease (AD) is a degenerative neurological condition characterized by cognitive decline, memory loss, and impaired daily functioning. A key feature of AD is the accumulation of amyloid-beta (Aβ) plaques, which initiate a series of pathological events, including neuroinflammation, synaptic dysfunction, tau pathology, oxidative stress, impaired protein clearance, mitochondrial dysfunction, and disrupted calcium homeostasis. Aβ is generated through the cleavage of the amyloid precursor protein (APP) via two pathways: the non-amyloidogenic pathway, which reduces Aβ production and has neuroprotective effects, and the amyloidogenic pathway, which leads to the production of toxic Aβ peptides, such as Aβ40 and Aβ42, contributing to neurodegeneration. The review explores the multifaceted role of Aβ in AD, examining both its beneficial and detrimental effects. Aβ has been found to exhibit antioxidant, neuroprotective, and memory-boosting properties under certain conditions. For instance, Aβ can act as an antioxidant by binding transition metals and reducing their participation in oxidative damage. It also demonstrates neuroprotective effects, such as protecting against oxidative stress and promoting neuronal survival and differentiation. Additionally, Aβ has been shown to enhance long-term potentiation (LTP) and improve memory retention, particularly through interactions with α7-nicotinic acetylcholine receptors. However, Aβ also plays a crucial role in the progression of AD. The accumulation of Aβ, particularly Aβ42, leads to the formation of amyloid plaques, which disrupt the blood-brain barrier (BBB) and contribute to neuroinflammation and synaptic dysfunction. Aβ oligomers, in particular, are highly toxic and contribute to neuronal damage and cell death. They interfere with NMDA receptors, disrupt calcium homeostasis, and induce oxidative stress, leading to synaptic impairment and cognitive decline. The review also discusses the interaction between Aβ and other factors, such as proteases like insulin-degrading enzyme (IDE), neprilysin, and cathepsin B, which play roles in Aβ metabolism and clearance. Additionally, the sequence alterations in Aβ, such as the conversion of aspartate to isospartate, can increase Aβ aggregation and toxicity. Overall, understanding the dual nature of Aβ and its complex interactions is crucial for developing effective therapeutic strategies to target Aβ metabolism, aggregation, and clearance, aiming to mitigate the detrimental consequences of AD.