Alzheimer’s disease has a higher incidence in older women, with a spike in cognitive decline that tracks with visceral adiposity, dysregulated energy homeostasis and bone loss during the menopausal transition^,. Inhibiting the action of follicle-stimulating hormone (FSH) reduces body fat, enhances thermogenesis, increases bone mass and lowers serum cholesterol in mice^{, , , –}. Here we show that FSH acts directly on hippocampal and cortical neurons to accelerate amyloid-β and Tau deposition and impair cognition in mice displaying features of Alzheimer’s disease. Blocking FSH action in these mice abrogates the Alzheimer’s disease-like phenotype by inhibiting the neuronal C/EBPβ–δ-secretase pathway. These data not only suggest a causal role for rising serum FSH levels in the exaggerated Alzheimer’s disease pathophysiology during menopause, but also reveal an opportunity for treating Alzheimer’s disease, obesity, osteoporosis and dyslipidaemia with a single FSH-blocking agent.