Human growth hormone levels can be modified in many ways, should you need to. We’ve seen that, depsite an interest in doing so, it is ill advised to increase levels unless you are clinically deficient. Significant health risks assoicated with high levels outweigh any potential benefits to body composition and fitness. For those who are defcient though, recombinant human growth hormone injections or secretagogues may be prescribed. We’ve also seen that human growth hormone levels can be increased by lifestyle modifications. Here we explore the evidence behind another popular avenue: growth hormone-boosting supplements.
- Arginine supplements can increase growth hormone levels by themselves, however they also dull the greater stimulating impact of exercise.
- Melatonin and GABA supplements can directly stimulate release, or indirectly by aiding sleep- at least in the very short term. More research is needed about the long term effects of continuous use.
- There is little or negative evidence for a range of other supplements, such as beta-alanine and various sports shakes.
Arginine and growth hormone
Arginine is a non-essential amino acid, meaning your body can synthesise it. However, some people aren’t content with this and use arginine supplements to boost their human growth hormone secretions (among other reasons…)
Exercise and arginine seem to have a moderating effect on each other. Now a couple of early studies suggested that arginine is more effective in boosting growth hormone if you abstain from exercise. This is controversial, not just because you’d clearly be losing a wide range of other benefits by not exercising- but because these studies were very small and do not provide enough statistical power to base decisions on.
In contrast, a more recent review indicated that:
- Arginine does increase resting growth hormone levels, however exercise is more effective than arginine
- Combining arginine with exercise does reduce the stimulating effect of exercise
- However, combining them remains more effective than using arginine alone.
The moral of the story is that if you are deficient and unable to exercise, arginine supplements could be a “plan B” option. But you can’t beat exercise.
Melatonin and growth hormone
As we’ve seen previously, slow wave sleep is particularly important for growth hormone secretion among men. Melatonin may indirectly boost levels by fostering better sleep… but may also increase levels independently of sleep…
GABA (gamma aminobutyric acid) and growth hormone
GABA is an amino acid that acts as a calming neurotransmitter and aids sleep. As with melatonin, it may increase the hormone release directly and by its effects on sleep.
One small randomised controlled trial among fit young men found that 3g of GABA supplementation on a singular occasion increased growth hormone levels both at rest and when followed by resistance exercise. In this study, combining exercise with supplementation was more effective than using either alone.
However, we do not know what the cumulative effects of long term supplementation are. We are also lacking experimental proof that GABA supplementation results in improved muscle mass or strength- the primary reason one might want to increase growth hormone levels!
In addition, evidence suggests that GABA may not always increase growth hormone secretion. A theory explaining this is that might increase or decrease secretion depending on whether it acts on the hypothalamus or the pituitary gland (the site where growth hormone is released)
Beta-alanine and specific sports drinks
Beta-alanine supplements are on the market. They seem to have no effect on growth hormone, although combined with exercise, they may increase physical performance… likely through other means.
A small study where a carbohydrate-protein containing sports drink was used in conjunction with exercise showed that it increased growth hormone response on day one… but this was attenuated by day 2 and 3. By this point levels were not significantly different to placebo, suggesting any effects are short-lived.
In another study, taking a supplement containing 25g of caseinate and whey proteins actually diminished the growth hormone response- obviously the opposite of what body builders/protein chuggers may want.
These studies, however, are limited by their small size (among other things) and more exploration is warranted.
Arginine supplements may be most advised if you are clinically deficient in growth hormone, are in need of body composition and strength.aerobic capacity improvements, but are unable to exercise. Melatonin and GABA have potential, but we do not know what effect they have when used regularly. While there is interest in a range of other supplements, they do not seem to be effective.
What supplements do you take and why?
Collier, S. R., Collins, E., and Kanaley, J. A. (2006). Oral arginine attenuates the growth hormone response to resistance exercise. Journal of applied physiology. 101(3): 848–852. https://doi.org/10.1152/japplphysiol.00285.2006.
Hulmi, J.J., Volek, J.S., Selänne, H., and Mero, A.A. (2005). Protein ingestion prior to strength exercise affects blood hormones and metabolism. Medicine and science in sports and exercise. 37(11):1990–1997. https://doi.org/10.1249/01.mss.0000175912.64126.f9
Kanaley J. A. (2008). Growth hormone, arginine and exercise. Current opinion in clinical nutrition and metabolic care. 11(1): 50–54. https://doi.org/10.1097/MCO.0b013e3282f2b0ad
Kraemer, W.J., Volek, J.S., Bush, J.A., Putukian, M., and Sebastianelli, W.J. (1998). Hormonal responses to consecutive days of heavy-resistance exercise with or without nutritional supplementation. Journal of applied physiology. 85(4):1544–1555. https://doi.org/10.1152/jappl.19188.8.131.524
Nassar, E., Mulligan, C., Taylor, L. et al. (2007). Effects of a single dose of N-Acetyl-5-methoxytryptamine (Melatonin) and resistance exercise on the growth hormone/IGF-1 axis in young males and females. J Int Soc Sports Nutr. 4(14). doi: 10.1186/1550-2783-4-14
Powers M. (2012). GABA supplementation and growth hormone response. Medicine and sport science. 59:36–46. https://doi.org/10.1159/000341944
Powers, M.E., Yarrow, J.F., McCoy, S.C., and Borst, S.E. (2008). Growth hormone isoform responses to GABA ingestion at rest and after exercise. Medicine and Science in Sports and Exercise. 40(1):104-110. DOI: 10.1249/mss.0b013e318158b518
Suminski, R. R., Robertson, R. J., Goss, F. L., et al. (1997). Acute effect of amino acid ingestion and resistance exercise on plasma growth hormone concentration in young men. International journal of sport nutrition. 7(1):48–60. https://doi.org/10.1123/ijsn.7.1.48
Trexler, E.T., Smith-Ryan, A.E., Stout, J.R., et al. (2015). International society of sports nutrition position stand: Beta-Alanine. Journal of the International Society of Sports Nutrition. 12(30). https://doi.org/10.1186/s12970-015-0090-y