For men with low testosterone, taking testosterone therapy may lower their overall cholesterol by about 7% after a year, but it doesn’t seem to change the 'bad' LDL cholesterol.

For men with low testosterone, taking testosterone therapy may lower their 'good' cholesterol by about 11% after a year, even though it helps other heart and metabolism factors get better.

Taking testosterone therapy might slightly lower the 'good' cholesterol and could raise the 'bad' cholesterol, which could change how your body handles fats in the blood.

For men with low testosterone, giving them testosterone therapy may lower their triglyceride-to-HDL ratio by almost 20% in a year — and if their ratio was already really high (above 6), it can drop by more than two-thirds, which is good because high ratios are tied to heart and metabolic problems.

Giving men extra testosterone seems to lower their 'bad' cholesterol and total cholesterol (which is good), but it also lowers their 'good' cholesterol (which might not be so good).

When men with low testosterone start taking testosterone therapy, their triglyceride (a type of fat in the blood) levels tend to go down—sometimes by almost half—if they started with high levels already. This suggests the therapy might help improve their blood fat numbers.