A new study published by researchers from Baylor University has offered new information about how glutathione and l-citrulline may work together to boost nitric oxide (NO) levels.Researchers recruited healthy young men who had been regularly using resistance training for at least a year to take part in the study. The 60 participants either took a placebo; l-citrulline (2 g/day); glutathione (1 g/day as Setria Glutathione from Kyowa Hakko, based in New York NY); or l-citrulline (2 g/day) plus glutathione (200 mg/day as Setria Glutathione) for one week. The group performed the same resistance exercise involving the elbow flexors, and blood samples were taken to analyze blood levels of components like NO and NOx (nitrite + nitrate).

After seven days, NO and NOx in the l-citrulline and glutathione combination group increased 30 minutes after exercise; the placebo group did not have such a change.  “We were able to determine that combining Setria Glutathione with L-citrulline not only increased blood levels of nitrite and NOx, but sustained the increases for a longer period of time, compared to placebo,” said Darryn Willoughby, lead researcher from Baylor University. This study is said to be the first of its kind to suggest that glutathione and l-citrulline in combination play a role in muscle protein synthesis and muscle performance following exercise.

These data will be published in the Journal of the International Society of Sports Nutrition.

Published in WholeFoods Magazine, August 2015, (online 7/10/2015)