This article explores the cultivation of medical knowledge via popular health guides among the Finnish lay populace from the 1890s to the 1970s. By using written reminiscences and newspaper articles as source material, the article discusses the relevance, popularity, and practical use of various printed health guides and manuals throughout Finland. We place particular focus on the late nineteenth to the early twentieth century as the period that experienced a high increase in lay education and literacy. By focusing on individual readers and their experiences of popular health guides, the article examines lay medical and health practices as the number of medical manuals dramatically increased from the late nineteenth century onwards. It also investigates the reception of medical, popular and irregular health movements, such as hygienism, nature cure, and Couéist autosuggestion, and the change in medical culture brought about by the appearance of patent medicines. As the information discovered in popular health guides tended to fluctuate between official and irregular medical theory, we analyse the relationship between learned, alternative, and vernacular medicine through the views and opinions expressed by people who engaged with health literature. Through these materials, we provide a novel understanding of the accessibility of medical knowledge, the spread and impact of health guides, and attitudes towards different medical practices among the Finnish reading public.