Erectile Dysfunction and Carnitine
L-carnitine (carnitine) is a substance used by the body uses to turn fat into energy. It is not normally considered an essential nutrient because the body can manufacture all it needs. However, supplemental carnitine could in theory improve the ability of certain tissues to produce energy. This has led to the use of carnitine for various muscle diseases as well as heart conditions.
Dietary sources of carnitine include eggs, fish, meat and dairy.
Effect of Carnitine on Erectile Dysfunction
Carnitine is best known and researched as an energy-boosting substance. The body uses it to turn fat into energy. Supplemental carnitine is used to improve the ability of certain tissues, such as muscle, to produce energy. It may be helpful for treating erectile dysfunction by enhancing the nerve functions that are involved in creating and maintaining an erection.
Research Evidence on Carnitine
In a 6-month, double-blind trial of 120 men, average age 66, carnitine (propionyl-l-carnitine 2 g/day plus acetyl-l-carnitine 2 g/day) and testosterone (testosterone undecanoate 160 mg/day) were separately compared to placebo.1 The results indicated that both carnitine and testosterone improve erectile function; however, while testosterone significantly increased prostate volume, carnitine did not.
Another double-blind, placebo-controlled study found that propionyl-l-carnitine at 2 g/day enhanced the effectiveness of Viagra (sildenafil) in 40 men with diabetes who had previously failed to respond to Viagra on 23 at least eight occasions.2
In another double-blind study, a combination of the propionyl and acetyl forms of carnitine enhanced the effectiveness of Viagra in men who suffered from erectile dysfunction caused by prostate surgery.3
Side Effects and Warnings
L-carnitine in its three forms appears to be quite safe. However, individuals with low or borderline-low thyroid levels should avoid carnitine because it might impair the action of thyroid hormone. ^ Individuals on dialysis should not receive this (or any other supplement) without a physician's supervision.
The maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.
#Interactions You Should Know About
If you are taking:
- Antiseizure medications, particularly valproic acid (Depakote, Depakene) but also phenytoin (Dilantin) : You may need extra carnitine.
- Thyroid medication: Do not take carnitine except under a physician's supervision.
- Cavallini G, Caracciolo S, Vitali G, et al. Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology. 2004;63:641-646.
- Gentile V, Vicini P, Prigiotti G, et al. Preliminary observations on the use of propionyl-L-carnitine in combination with sildenafil in patients with erectile dysfunction and diabetes. Curr Med Res Opin. 2004;20:1377-1384.
- Cavallini G, Modenini F, Vitali G, et al. Acetyl-L-carnitine plus propionyl-L-carnitine improve efficacy of sildenafil in treatment of erectile dysfunction after bilateral nerve-sparing radical retropubic prostatectomy. Urology. 2005;66:1080-1085.
- Benvenga S, Lakshmanan M, Trimarchi F. Carnitine is a naturally occurring inhibitor of thyroid hormone nuclear uptake. Thyroid. 2000;10:1043-1050.