Are L-Citrulline Supplements a Safe Treatment for Erectile Dysfunction?

What Is L-Citrulline?


  1. L-citrulline is an amino acid normally made by the body. It helps improve blood flow.
  2. Watermelon is one of the largest food sources of L-citrulline.
  3. The research to support the use of L-citrulline as an ED treatment is limited but promising.

L-citrulline is an amino acid normally made by the body. In the body, L-citrulline is converted to L-arginine, another type of amino acid.

L-arginine improves blood flow. It does so by creating nitric oxide (NO), a compound that helps widen blood vessels. L-arginine has been shown to help people with heart disease or clogged arteries because of its vessel-widening abilities.

Arginine: Good for the Heart

The same effect on blood vessels helps ease symptoms of erectile dysfunction (ED). The L-citrulline to NO path increases blood flow to a man’s genitals. In one study, this increase in blood flow appeared to decrease symptoms of mild ED and improve the ability to maintain an erection. No studies have examined the use of L-citrulline in moderate to severe cases of ED.


L-Citrulline Supplements

How Can You Get L-Citrulline in Your Diet?

Watermelon is one of the largest food sources of L-citrulline. Legumes, meat, and nuts also contain the amino acid. However, most individuals use supplements to increase the amount of L-citrulline in their diet.

L-citrulline supplements are available over the counter. Few peer-reviewed, credible studies have looked at the proper dosing for L-citrulline. Therefore, no official dosing recommendation exists.

However, one study from the British Journal of Nutrition found that doses between 2 and 15 grams were safe and well tolerated by the men in the study. Supplements available in stores range from 500 milligrams to 1.5 grams. Some supplements contain a mixture of L-citrulline and other ingredients. Read the supplement label to see exactly how much of the amino acid you’re getting with each dose.


Side Effects

Concerns and Side Effects

The research to support the use of L-citrulline as an ED treatment is limited but promising. Treatment with traditional ED medications, phosphodiesterase type 5 inhibitors (Viagra, Levitra, and Cialis), has been proven to be very effective. However, some men prefer not to use those medications because of possible risks or side effects. This may be true especially for men who experience only mild ED issues.

In that case, the use of L-citrulline may be preferable, at least for short periods of time. L-citrulline is safe, and studies have not revealed any known side effects. If you’re taking any other medications, however, it’s important you talk with your doctor about possible interactions.


Natural ED Remedies

Other Natural Remedies for ED

Not every man experiencing ED problems will want to use conventional prescription medications. Other nondrug treatments exist. If you’re looking for natural remedies to ease your ED symptoms, these might be good places to start. As with all natural remedies, consult your doctor before taking anything.

5 Natural Treatments for Erectile Dysfunction

Penile Pumps

Penile pumps are a noninvasive way to treat ED. It’s used just before sexual intercourse to increase blood flow to the penis. If used incorrectly, it can cause bruising and pain.

Penile Implants

Implants can be surgically inserted into the penis and then inflated prior to sexual intercourse.


Panax ginseng has been shown in multiple, peer-reviewed studies to be a safe, effective treatment for ED.


Dehydroepiandrosterone (DHEA) is a hormone naturally produced by the body’s adrenal glands. Although there are no recent studies, one older study showed that men with ED issues often have low DHEA levels. Supplementing those levels might help improve muscle strength in older adults. However, more up-to-date research is needed.


This form of complementary medicine involves sticking needles into upper layers of skin and tissue. This practice has been used for centuries to ease pain, alleviate chronic problems, and treat various conditions.

One study in the International Journal of Impotence Research found that about a quarter of the men in the study who received acupuncture had improved erections and were able to perform sexually.


Seeking Help

When to See a Doctor

If you’re facing ED issues and want to find a way to ease the symptoms, talk with your doctor.

If you’re leery of taking traditional ED medications, such as sildenafil (Viagra) or tadalafil (Cialis), because of potential side effects talk to your doctor about other options. Supplements like L-citrulline and natural remedies show some promise in the treatment of ED. Your doctor can help you find a treatment plan that is safe and less likely to cause side effects or problems.

Many men are hesitant to talk about these sensitive issues, but the sooner you ask for help, the sooner you can find the answers and treatment you need.

Article Resources
  • Cormio, L., De Siati, M., Lorusso, F., Selvaggio, O., Mirabella, L., Sanguedolce, F., & Carrieri, G. (2011, January). Oral l-citrulline supplementation improves erection hardness in men with mild erectile dysfunction [Abstract]. Urology, 77(1), 119-122. Retrieved from
  • Engelhardt, P. F., Daha, L. K., Zils, T., Simak, R., Konig, K., & Pfluger, H. (2003, October). Acupuncture in the treatment of psychogenic erectile dysfunction: First results of a prospective randomized placebo-controlled study [Abstract]. International Journal of Impotence Research, 15(5), 343-346. Retrieved from
  • Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994, January). Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study [Abstract]. The Journal of Urology, 151(1), 54-61. Retrieved from
  • Jang, D. J., Myeong, S. L., Byung-Cheul, S., Young-Cheoul, L., & Ernst, E. (2008, October). Red ginseng for treating erectile dysfunction: A systematic review. British Journal of Clinical Pharmacology, 66(4), 444–450. Retrieved from
  • Moinard, C., Nicolis, I., Neveux, N., Darguy, S., Benazeth, S., & Cynober, L. (2008, April). Dose-ranging effects of citrulline administration on plasma amino acids and hormonal patterns in healthy subjects: The citrudose pharmacokinetic study [Abstract]. British Journal of Nutrition, 99(4), 855-862. Retrieved from
  • Reiter, W. J., Pycha, A., Schatzl, G., ... Marberger, M. (1999). Dehydroepiandrosterone in the treatment of erectile dysfunction: a prospective, double-blind, randomized, placebo-controlled study. Urology, 53(3), 590-595. Retrieved from