Adiponectin is a naturally occuring peptide hormone in the body, it contains 244 amino acids and has a similar structure to Tumor Necrosis Factor alpha (TNFα).
Adiponectin has an important role in the regulation of glucose and fatty acid metabolism and is secreted exclusively from adipocytes (fat cells). Blood concentration of adiponectin have a direct inverse relationship with bodyfat levels in adult humans 
Recent interest in adiponectin as an anti-obesity drug has spurred multiple clinical trials. Adiponectin has multiple actions in the body, it can act directly on the hypthalamus to regulate eating (similar to Leptin), reverse insulin resistance, decreases gluconeogenesis, reverse atherosclerosis, increases glucose uptake , stimulates beta-oxidation of fatty acids and upregulates uncoupling proteins.
Upregulating uncoupling protein has a similar effect to taking the metabolic poison/fat loss aid 2,4-Dinitrophenol. It acts by preventing the last step in the oxidative phoshphorylation in the mitochondria – this causes the body to run more inefficiently and thus produce more energy as heat rather than for kinetic purposes.
The evidence so far points at adiponectin as possibly the cure for obesity. It is able to prevent adipocyte differentiation and positively affect fatty acid metabolism and prevent the formation of glucose in the liver (gluconeogenesis), it’s able to reverse insulin resistance (a common condition of people with Diabetes Type II and hyperinsulinemia).
It may even be a predictor of a woman’s chances of developing breast cancer – low levels of adiponectin are found in women with breast cancer.
Is it safe though? Pharmaceutical companies are already beginning to claim that it’s the cure for obesity we’ve been waiting for and some companies are selling it already.
Research conducted at the University of Gothenburg , shows that adiponectin can increase the risk of osteoporosis in the elderly. This is possibly due to increased metabolic activity in osteoclast cells leading to resorption of bones and thus a weakening of the skeleton. The research found that elderly men with high levels of adiponectin had lower muscle mass, were weaker and had weaker bones and joints. That rules out the elderly for this drug.
There is no research that it adiponectin works in children and thus that leaves us with adults. There is currently no conclusive research that indicates that there are adverse side effects in adults making adiponectin quite safe to use – in low doses of course.
If one was against injecting adiponectin, levels of adiponectin can be raised in the body by Omega-3 fatty acids (such as EPA, eicosapentanoic acid). Another benefit to add to the list for Omega-3 Fatty Acids.