Ornithine strengthens mental effects of caffeine
The stimulant caffeine has more effect when combined with the amino acid ornithine write researchers at the Japanese Kirin Company in Preventive Nutrition and Food Science. According to the Japanese, ornithine not only enhances the desirable mental effects of caffeine, it also helps these effects to last longer.
Ornithine - caffeine
In December 2013 the researchers at the Kirin Company obtained the American patent for supplements and foods that have a stimulatory effect as a result of the combination of ornithine and caffeine. [[US20130324563 A1] Six weeks later, in mid February 2014, Kirin launched ON Powered Refreshment: a soft drinks line containing the patented combination. [bevnet.com February 17, 2014]

And a few months later again, in the summer of 2014, the researchers sent their human study on the effects of the ornithine-caffeine mix to the editors at Preventive Nutrition and Food Science.

The researchers gave 19 employees of the company a capsule containing 100 mg caffeine [above, structural formula shown in the centre] and 250 mg ornithine HCL at 9.30 in the morning. The latter dose is equivalent to 200 mg ornithine [structural formula on the left]. On another occasion the subjects were given a capsule containing only 100 mg caffeine, and on yet another occasion a capsule containing no active ingredients.


Just before the subjects took the capsule the researchers measured the cortisol concentration in their saliva. They repeated this an hour later and discovered that the ornithine-caffeine combination reduced the concentration of cortisol.

The researchers got the subjects to fill out questionnaires to find out how healthy they were feeling [Vigor], and discovered that the combination enhanced this feeling more than caffeine did on its own.
The ornithine-caffeine combination also resulted in a stronger decrease in fatigue and an increase in clear mindedness.