L-Glutamine
"Nine healthy subjects (32-64 year old) ingested 2 grams of L-glutamine."
"The rise of growth hormone occurred 90 minutes after oral ingestion in seven out of eight subjects and it exceeded the time control value by 4-fold. "
"Glutamine might convert to citrulline in the small intestine which supports renal arginine synthesis, a known stimulus for growth hormone secretion. Glutamine also converts to glutamate which provides a stimulus for directly activating somatotrophic growth hormone release."
[1]http://nutrientjournal.com/glutamine-benefits-can-it-boost-growth-hormone/"Increased plasma bicarbonate"
"These findings demonstrate that a surprisingly small oral glutamine load is capable of elevating alkaline reserves as well as plasma growth hormone."
[1]References:
[1]
https://www.ncbi.nlm.nih.gov/pubmed/7733028