Testosterone may be used to treat men with multiple sclerosis (MS), after a new study suggested that the treatment is safe.
The disease is more common in women than in men and tests have found that testosterone protects against MS and other autoimmune diseases.
Scientists tested testosterone on ten men with relapsing-remitting MS, each applying testosterone gel once a day for 12 months.
The authors of the study wrote: "One year of treatment with testosterone gel was associated with improvement in cognitive performance and a slowing of brain atrophy [deterioration]."
Decrease in brain volume was found to slow by 67 per cent following treatment with testosterone.
The authors continued: "Because the protective effect of testosterone treatment on brain atrophy was observed in the absence of an appreciable anti-inflammatory effect, this protection may not be limited to MS, but may be applicable to those with non-inflammatory neurodegenerative disease.
"Overall, in this first trial of testosterone treatment in men with relapsing-remitting MS, the treatment was shown to be safe and well tolerated."