Medicinal plants, bioactive compounds, and dietary measures have been found to be effective in the treatment of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). About 463 million people have diabetes worldwide; estimates project 700 million people by 2045. While T1DM is caused by the loss of beta cells of pancreatic islets that produce insulin, resulting in the deficiency of insulin, T2DM, which constitutes over 90 to 95% of all DM cases, is caused by insulin resistance, and could relatively combine reduction in the secretion of insulin. Aloe vera,Terminalia chebula, Perilla frutescens, Curcuma longa, Zingiber zerumbet, Nigella sativa, Gongronema latifolium, Pachira aquatic, Caesalpinioideae, Azadirachta indica, Artemisia dracunculus, Artemisia herbaalba, Vachellia nilotica, Abelmoschus moschatus, Cinnamomum verum, Salvia officinalis,Tinospora cordifoli, Pterocarpus, Ocimum tenuiflorum, Mangifera indica, Syzygium cumini, Coccinia grandis, Caesalpinia bonduc, Gymnema sylvestre, Carthamus tinctorius, Allium sativum, and Trigonella foenum-graecum are among the medicinal plants shown to be effective in controlling and treating T1DM and T2DM. Bioactive compounds such as lycopene, vitamin E, vitamin D, genistein, quercetin, resveratrol, epigallocatechin-3-gallate, hesperidin, naringin, anthocyanin, etc. are useful in treating T1DM and T2DM.