Obesity affects 13 to 32 percent of the population, according to a 2007 report in "Epidemiologic Reviews." Thus, many people remain at risk for long-term consequences such as heart attack and stroke. Surgical treatments for obesity can be effective but may cause unwanted side effects. These treatments change the body's chemistry, indicating that hormone injections can produce comparable results. Such natural treatments may provide a safer alternative for people wanting to lose weight.
The hormone leptin produces feelings of fullness, so leptin injections should suppress appetite and trigger weight loss. A 1999 experiment described in the "Journal of the American Medical Association," or "JAMA," tested this hypothesis in obese men and women. Participants self-injected either leptin or placebo each morning for four weeks. These injections led to weight loss in all subjects. More importantly, the patients did not experience any side effects other than minor injuries at the injection site.
Ciliary Neurotrophic Factor
The substance ciliary neurotrophic factor triggers the production of luteinizing hormone and prolactin. These three hormones play a critical role in female reproduction. They may also regulate the changes in body weight associated with the menstrual cycle. A 2003 paper in "JAMA" looked at the impact of ciliary neurotrophic factor on body weight. Scientists injected obese adults with either ciliary neurotrophic factor or placebo daily for 12 weeks. Results indicated that hormone intake caused weight loss relative to placebo. Many patients, however, experienced side effects. Yet, most of these reactions were caused by the injection, not the hormone.
The peptide YY3-36 suppresses appetite, making it a candidate as a weight-loss hormone. A 2003 study in the "New England Journal of Medicine" evaluated this hypothesis in obese and lean subjects. Men and women received either YY3-36 or placebo during a single testing session. They returned to the laboratory at a later date for the opposite condition. All subjects receiving YY3-36 consumed fewer calories following hormone intake. No negative reactions were reported.
The medical literature has revealed other hormones that may help people lose weight. These experimental treatments have not been tried in human subjects, but testing in animal models has shown promise. A 2010 report in "Current Aging Science" assessed the effect of thyroid-releasing hormone. Researchers gave rodents either this hormone or placebo for an extended period. Mice given thyroid-releasing hormone experienced weight loss and fat breakdown. The treatment caused no adverse events in the animals.
Another experimental treatment with potential as a weight-loss hormone is exendin-4. This substance keeps food in the stomach longer and thereby suppresses appetite. A 2011 publication in "Obesity" looked at the impact of exendin-4 on the body weight of laboratory animals. Relative to placebo, the hormone treatment reduced body weight of obese rats over a 10-week testing session. Interestingly, occasional withdrawal periods were required to maintain the effect, and the addition of YY3-36 produced no further benefit.