Carnitine is an amino acid that is heavily involved in producing energy for the body. But carnitine also can play a key role in erectile dysfunction and libido. When researchers compared carnitine with testosterone in men who were experiencing low libido, fatigue, and depression, they found that after six months of treatment, both carnitine and testosterone improved erections and sexual performance, and carnitine was more effective than the hormone.
In fact, testosterone caused an increase in prostate volume and size, while carnitine did not. Both supplements provided significant improvement in fatigue and depression as well. (Cavallini)
If carnitine is on your list of erectile dysfunction supplements to try, do so only under the supervision of a knowledgeable healthcare professional. Doses of 3 grams daily may cause nausea, vomiting, diarrhea, and a fishy body odor.
Reference
Cavallini G et al. Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology 2004 Apr; 63(4): 641-46