Tinospora cordifolia, commonly known as Giloy, is a heart-leaved moonseed, also known as Guduchi, and is considered a divine herb. Twenty-four species of an herbaceous vine are found in tropical areas of India, Myanmar, and Sri Lanka, among others. This study aims to comparatively evaluate the influence of host plants Azadirachta indica (Neem), Saraca asoca (Ashoka), Citrus limon (Lemon), and normal giloy (independently growing) based on their phytochemical screening, antioxidant activity, antidiabetic activity, and total flavonoid content. Phytochemical screening reveals the presence of carbohydrates, steroids, glycosides, quinones, phytosterols, flavonoids, proteins, and amino acids. Quantitative estimation revealed that normal T. cordifolia without a host exhibited the highest total flavonoid content. Using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, the neem-hosted plant shows the highest antioxidant activity, and the neem-hosted giloy and regular giloy showed the highest inhibitory activity in the antidiabetics (α-amylase test). The studies suggest that the host plant affects the bioactive profile of T. cordifolia.