In the few human studies that exist, a single oral dose of GABA (3–5 grams) was found to increase circulating growth hormone concentrations at rest[1][2][3] and in response to resistance exercise.[3] An increase in resting growth hormone concentrations has also been found in participants with no health conditions following intravenous injection with baclofen, a drug that activates GABAB receptors,[4] but not alprazolam, a GABAA receptor activator.[5][6] However, the growth hormone-increasing effects of GABA[2] and baclofen[7] attenuate with daily use.
Overall, the effects of GABA on circulating growth hormone concentrations are complex. Although high-dose supplementation with GABA can significantly increase growth hormone levels, the effects attenuate rapidly, within a few days.[2] It is not currently clear whether the effects of GABA on human growth hormone have meaningful effects on health or athletic performance.
References
- ^Cavagnini F, Benetti G, Invitti C, Ramella G, Pinto M, Lazza M, Dubini A, Marelli A, Müller EEEffect of gamma-aminobutyric acid on growth hormone and prolactin secretion in man: influence of pimozide and domperidone.J Clin Endocrinol Metab.(1980-Oct)
- ^Cavagnini F, Invitti C, Pinto M, Maraschini C, Di Landro A, Dubini A, Marelli AEffect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man.Acta Endocrinol (Copenh).(1980-Feb)
- ^Powers ME, Yarrow JF, McCoy SC, Borst SEGrowth hormone isoform responses to GABA ingestion at rest and after exercise.Med Sci Sports Exerc.(2008-Jan)
- ^Volpi R, Gerra G, Vourna S, Vescovi PP, Maestri D, Chiodera P, Coiro VFailure of the gamma-aminobutyric acid (GABA) derivative, baclofen, to stimulate growth hormone secretion in heroin addicts.Life Sci.(1992)
- ^Hedrington MS, Mikeladze M, Tate DB, Younk LM, Davis I, Davis SNEffects of γ-Aminobutyric Acid A Receptor Activation on Counterregulatory Responses to Subsequent Exercise in Individuals With Type 1 Diabetes.Diabetes.(2016-Sep)
- ^Hedrington MS, Tate DB, Younk LM, Davis SNEffects of Antecedent GABA A Receptor Activation on Counterregulatory Responses to Exercise in Healthy Man.Diabetes.(2015-Sep)
- ^Cavagnini F, Invitti C, Di Landro A, Tenconi L, Maraschini C, Girotti GEffects of a gamma aminobutyric acid (GABA) derivative, baclofen, on growth hormone and prolactin secretion in man.J Clin Endocrinol Metab.(1977-Sep)