Instead of giving growth hormone directly, this drug tricks the body into making its own in a natural rhythm, which might be safer for blood sugar.

After a year of taking tesamorelin, obese people with low growth hormone had much higher levels of IGF-I than those who took a sugar pill — proving the drug works as intended.

The drug didn’t make blood sugar or insulin levels better, so its benefits must come from somewhere else — likely directly on muscle energy production.

Taking tesamorelin for a year makes IGF-I levels rise much more in obese people with low growth hormone than taking a dummy pill, with a clear difference between the two groups.

Taking tesamorelin for a year makes the hormone IGF-I go up much more in obese people with low growth hormone compared to taking a sugar pill.

The drug raised IGF-I levels by about 1.7 standard deviations — a big, normal-range boost that shows the treatment worked well without going overboard.