Sniffing 'love hormone' can help men reduce calorie intake

A new study has revealed that a synthetic nasal formulation of the love hormone, called Oxytocin, can help men eat fewer calories.

Oxytocin nasal spray reportedly lowered the number of calories men consumed at a subsequent breakfast whether they were normal weight or overweight.

In addition, the researchers found that oxytocin improved metabolic measures, such as insulin sensitivity, which was the body's ability to successfully clear glucose (sugar) from the bloodstream.

The oxytocin nasal spray (made by Novartis) has been approved in Europe but not in the U.S. other than in clinical trials. Oxytocin is available in the U.S. as an intravenous or injectable drug (Pitocin) to induce labor.

On average, the men ate 122 fewer calories and 9 grams less fat at the meal after they received oxytocin nasal spray compared with placebo, the study data showed. Oxytocin also reportedly increased the use of body fat as a fuel for energy.

Elizabeth Lawson, assistant professor of medicine at Harvard Medical School, Boston said that there were no serious side effects and no difference in side effects between oxytocin and placebo.

Oxytocin had no effect on self-reported appetite or on appetite-regulating hormones measured in their blood, the researchers discovered. Therefore, how oxytocin affected caloric intake is unclear, Lawson said. In preclinical studies, oxytocin was involved in appetite-reducing pathways in the brain.

Because oxytocin has sex-specific effects, it needs to be studied in women, as well as in both sexes for extended treatment duration.