Doctors use CT scans to measure how dense fat is — denser fat means the fat cells are smaller and healthier, even if you can’t see them directly.

Before starting the drug, the fat quality in the group that got the drug was just like the group that got the placebo — so any differences later were due to the treatment.

Before treatment, the fat under the skin looked just as healthy on scans in both the drug and placebo groups — so any changes later were caused by the drug.

In HIV patients with belly fat who responded to tesamorelin, denser visceral fat (on CT scans) was associated with less visceral fat area, showing that fat quality and quantity are related.

The fat gets healthier-looking on scans even if the amount of fat doesn’t change — the drug is improving the fat itself, not just shrinking it.

The drug makes the fat around the organs healthier-looking on scans more than the fat under the skin — it works better on belly fat than on thigh or arm fat.