Gymnema (Gymnema sylvestre)

Andrographis, commonly known as Green Chiretta or King of Bitters, is an upright annual herb reaching approximately 3 feet in height. Native to India and cultivated throughout northern regions of India and China, this bitter medicinal plant has been valued in Ayurvedic and traditional Chinese medicine for centuries. MSK notes that it has been studied mostly for colds, flu and upper respiratory infections. The plant thrives on plains and in forest undergrowth, where its spotted pale brown or purple flowers and long seed capsules distinguish it from other medicinal herbs.

Bitter melon is an annual climbing vine reaching about 6.5 feet, characterized by deeply lobed leaves, yellow flowers, and distinctive orange-yellow fruit. Native to southern Asia and now common throughout tropical regions worldwide, it is harvested year-round. Its edible fruit is used both as food and in medicine to treat diabetes in regions including Asia, East Africa and the Caribbean; MSK says data on whether it lowers blood sugar are limited.

Cinnamon (Cinnamomum verum or C. zeylanicum) is a small evergreen tree, prized for its fragrant, sweet-spicy bark. Cinnamon has a long history of use in traditional medicine in China, India and Persia, where it was thought to help inflammation, nerve pain, heart disease and cough (NCCIH). NCCIH says research doesn't clearly support cinnamon for any health condition, and it is unclear whether it helps diabetes.

Fenugreek is much used in herbal medicine in North Africa, the Middle East, and India. Its seeds have been used to increase breast-milk production; NCCIH says studies of this use have had mixed results. Fenugreek is also thought to be antidiabetic, although NCCIH says there is not enough high-quality evidence to know whether it helps diabetes.

Fringe tree is a deciduous shrub or tree growing to 33 feet with elliptical dark green leaves, long flowering stems bearing spikes of white flowers, and dark blue oval fruits. Native to the United States and now also found in eastern Asia, it grows from Pennsylvania south to Florida and Texas and thrives on riverbanks and in damp shrubby areas. The root is unearthed in spring or autumn, mostly in Virginia and North Carolina.

Goat's rue is a bushy perennial herb growing to approximately 3 feet in height, with compound leaves bearing lance-shaped leaflets, delicate pink pea-type flowers arranged on terminal spikes, and red-brown seed pods that form in autumn. Native to Asia and continental Europe and naturalized in Britain, it grows in damp and low-lying areas and is harvested in summer. Goat's rue has been widely cultivated as cattle feed. Its common name hints at its long association with livestock.

Jambul (Syzygium cumini) is an evergreen tree reaching about 33 ft (10 m), with lance-shaped leaves, greenish-yellow flowers, and edible, dark-colored fruit.

Neem (Azadirachta indica) is a large evergreen tree with compound leaves and white flowers, known in India as the “village pharmacy”. It is used in traditional and Ayurvedic medicine for skin conditions and stomach ailments; MSK says studies on its safety and effectiveness are lacking.