LEP and relapsing-remitting multiple sclerosis: The difference in serum leptin concentration of the two genders is well known.12, 13 Moreover, the results suggest that testosterone, as a gonadal hormone, may be one of the important regulators of leptin secretion.14 Recently it has been shown that testosterone therapy is safe and has potential neuroprotective effects in men with relapsing-remitting MS, and that muscle mass significantly increased after this treatment.15