In a 2019 study, tesamorelin improved mitochondrial function in obese people with low growth hormone, as measured by better phosphocreatine recovery after exercise, and this improvement was linked to increased IGF-1 levels.

When obese people with low growth hormone took a drug called tesamorelin for a year, their muscle energy recovery got better, which means their muscle cells may have become better at making energy.

In obese people with low growth hormone taking tesamorelin, higher IGF-I levels are linked to better mitochondrial energy efficiency, measured by τPCr.

We know muscle energy recovery got better, but we don’t know if it’s because there are more mitochondria, bigger ones, or just ones that work better.

Because so few people finished the study and the muscle energy didn’t improve much more in the drug group than the placebo group, we can’t say for sure the drug caused the improvement.

In obese people with low growth hormone taking tesamorelin, the link between higher IGF-I and better muscle energy recovery is even stronger than in the whole group of participants.