Current practice states that men with prostate cancer should not receive testosterone as it is thought to accelerate an active case. Note that testosterone is not thought to cause prostate cancer, but may speed up the severity of the disease. Men who are, or have been treated for prostate cancer are at risk for the fatigue and decreased libido of low testosterone as well. Since hormone replacement is typically not recommended for this group, other options are needed. A special combination of two forms of the nutritional supplement carnitine has shown equal effectiveness in battling fatigue and maintaining well being [Source: Cavallini ]. This combination contains 2,000 mg of acetyl L-carnitine and 2,000 mg of propionyl L-carnitine. The heart benefits that are seen with testosterone replacement have not been studied with this combination.