New research suggests that lipodystrophy sufferers should approach metformin with caution. The study, published in the October HIV Medicine, found little benefit and reasons for concern when using metformin to improve some of the side effects commonly associated with lipodystrophy.

Researchers in Boston enrolled 48 men and women who’d accumulated significant fat at the waistline and had mild insulin resistance. Participants were randomly assigned to take either 1500mg of metformin, an anti-diabetes drug, or a placebo for 24 weeks. The researchers conducted computerized and X-ray scans of body fat and measured insulin sensitivity and cholesterol at baseline and at 24 weeks.

In the study, people taking metformin had no significant changes in visceral fat mass or insulin sensitivity compared to the placebo group. They did, however, lose fat in their arms and legs, leading researchers to recommend that metformin only be used in people who have more severe insulin resistance and no peripheral fat loss.