What is ornithine? Why do we need it?
Ornithine is an amino acid manufactured by the body. It is
produced when another amino acid, arginine, is metabolized
during the production of urea, a substance found in human
urine. It plays an important role in the metabolism of nitrogen
and is believed to stimulate the release of growth hormones.
Several studies have been conducted on the benefits of ornithine,
primarily in body builders. Some studies have found that a
combination of ornithine and arginine may promote muscle-building
activity; other studies have reported increases in lean muscle
mass and strength, but these studies have yet to be confirmed
Other clinical studies have found different uses for ornithine.
A 1994 study on people with acute illnesses suggested that
supplements of ornithine alpha-ketoglutarate helped improve
appetite, weight gain and quality of life. Another study conducted
in 1998 showed that ornithine alpha-ketoglutarate supplementation
improved wound healing and decreased hospital stays in people
with severe burns.
How much ornithine should I take?
Most people do not benefit from ornithine supplementation.
However, the vast majority of human ornithine studies involve
between 5-10 grams of the substance, sometimes in combination
with arginine. Some sports physicians recommend between 1,500-2,500mg
of ornithine twice daily to stimulate muscle growth.
What are some good sources of ornithine?
What forms are available?
In addition to being produced naturally by the body, ornithine
can be found in meat, fish, dairy products and eggs. The typical
Western diet provides about five grams of ornithine per day.
What can happen if I don't get enough
ornithine? What can happen if I take too much? Are there any
side-effects I should be aware of?
Since ornithine is produced naturally, it is highly unlikely
a deficiency would occur; however, pregnant women and people
who have suffered severe trauma or malnutrition may become
ornithine deficient. Some patients have experienced gastrointestinal
disturbances and insomnia when taking more than 10 grams of
ornithine per day.
As of this writing, there are no known drug interactions
- Brocker P, Vellas B, Albarede JL, Poynard
T. A two-centre, randomized, double-blind trial of ornithine
oxoglutarate in 194 elderly, ambulatory, convalescent subjects.
Age Ageing 1994;23:3036.
- Bucci LR, Hickson JF, Wolinsky I, et al.
Ornithine supplementation and insulin release in bodybuilders.
Int J Sport Nutr 1992;2:28791.
- De Bandt JP, Coudray-Lucas C, Lioret N,
et al. A randomized controlled trial of the influence of
the mode of enteral ornithine alpha-ketoglutarate administration
in burn patients. J Nutr 1998;128:5639.
- Elam RP, Hardin DH, Sutton RA, et al.
Effects of arginine and ornithine on strength, lean body
mass and urinary hydroxyproline in adult males. J Sports
Med Phys Fitness 1989;29:526.
- Zieve L. Conditional deficiencies of ornithine
or arginine. J Am Coll Nutr 1986;5:167-76.