In Case You Missed It
Human growth hormone, or HGH as it’s colloquially known, is nothing new. But over the years, the public, medical community, and athletes alike have paid more and more attention to the substance. So what are the HGH benefits that have everyone so interested?
Increasing research and a better understanding are undoubtedly responsible for the increased attention.
Human growth hormone – like any substance with a sliver of medicinal promise – has all the hallmarks of a crowd favorite.
One such advantage is the body’s natural production of the substance. Supplement manufacturers and sellers alike frequently cite this fact as a way to ease any apprehensions consumers may have about the hormones.
After all, if your body already produces it, how bad can it be?
The claim has substance. The brain’s pituitary gland produces the hormone, “spurring growth in children, regulating body composition, fluids, muscle, bone growth, sugar and fat metabolism, and possibly heart function.” 1
But a better understanding of HGH benefits necessitates splitting how it’s used into two categories.
FDA Approved Uses
The Food and Drug Administration (FDA) approved synthetic human growth hormone based drugs to treat certain HGH deficiencies. Chief amongst them; Turner’s Syndrome, PWS (Prader-Willi Syndrome), and pituitary tumor complications.
Non-FDA Approved Uses
But it’s the non-FDA approved uses that garner the most attention. This is the miracle domain. Amongst just some of these HGH benefits are; anti-aging, increased lean body mass, reduced body fat, hair restoration, better sleep, improved sex, and a sharper memory.
How It Works
Fortunately, medical efforts to understand HGH stretch back to the 1940’s.2 As a result, we have a treasure trove of data and research. This large amount of data bestows a greater understanding of how the hormone operates and the advantages it confers.
Although we briefly mentioned that the pituitary gland naturally produces the hormone – generally following a circadian rhythm – research elucidated how HGH’s operates.
Simply put, once released from the pituitary gland, the hormone enters the bloodstream. At that point the liver appropriates it toward all the growth-related processes we’ve come to associate it with.
Mostly, the process relies on the insulin-like growth factor-1 (IGF-1),3 which can be thought of as the vehicle driving the change.
But what are these HGH benefits, and are they all real as we assume?
HGH Benefits: Does The Research Agree?
The Fitness Trifecta
In other words, the researchers wondered whether HGH helped subjects attain this holy trinity.
At the study’s conclusion, they found out that it indeed did. The researchers stated that “growth hormone has a role in the regulation of body composition in adults, probably through its anabolic and lipolytic actions.”
Specifically, “lean body mass increased by 5.5±1.1 kg, fat mass decreased by 5.7±0.9 kg, and the basal metabolic rate, measured at baseline and after one and six months of rhGH administration, increased significantly; the respective values were 32.4±1.4, 37.2±2.2, and 34.4±1.6 kcal per kilogram of lean body mass per day.”
The uptick in subjects’ Basal Metabolic Rate was particularly impressive as it increased by 5 calories, per kilogram.
Height Increase in Deficient Adults
A Danish study5 looked at another supposed advantage. In that experiment, the researchers administered hormone therapy to 13 growth hormone deficient adults while measuring any potential effects on height.
Over the course of 4 months, the subjects experienced “a significant mean increase of 1.3 cm in linear height, as well as mean thigh muscle volume growth when compared with the initial placebo period.”
Bone Health and Growth
Another study,6 published in Bone Journal, examined the link between HGH and fracture healing. The research revealed “accelerated bone regeneration.”
As part of their findings, the authors expounded the exact mechanics, stating; “the systemic administration of growth hormone (GH) has shown to accelerate bone regeneration. Local application of growth factors, such as insulin-like growth factor-1 (IGF-1) and transforming growth factor-β-1 (TGF-β1), are known to stimulate bone metabolism.”
Further, an earlier study 7 reflected the aforementioned findings when researchers “administered human growth hormone in vivo to rat cartilage growth plates.” As a result, the animals experienced “accelerated longitudinal bone growth.”
The authors concluded that the findings show “that growth hormone directly stimulates the cells in the growth plate.”
Finally, in a 2004 report, 8 the Office of the US Surgeon General stated: “the growth hormone may also directly affect the bone—that is, not through IGF-1.”
Essentially, like earlier studies, the Surgeon General’s report confirms that unlike other HGH benefits (anti-aging, height increase, positive body recomposition, etc.), the growth hormone can affect bone formation without the IGF-1 intermediary.
The substance’s anti-aging properties may be more superficial than its deficiency curing powers, but to some, they’re just as important.
Naturally, when something garners so much public attention, curious researchers start investigating.
In an Endocrine Reviews article,9 they did just that. The authors based their research on the finding that “with advancing age, an increasing proportion of men and women with no clinical evidence of pituitary pathology show decreases in GH secretion.”
Using that notion as their springboard, the researchers noted other conditions associated with aging, including; “decreases in protein synthesis and lean body and bone mass, and increases in body fat.”
Reconciling these assertions, it’s plausible that reduced growth hormone secretion and IGF-1 levels are catalysts in the aging process, thereby attenuating lean body mass and protein synthesis rates while increasing body fat storage.
In fact, the article authors posited the link and stipulated that “some older people might benefit from treatment with rhGH and that in several recent studies, administration of rhGH for periods varying from a few weeks to 6 months have resulted in improvements in nitrogen balance, an increase in lean body mass, and a decrease in percent body fat in older persons with low IGF-I levels.”
Good, we’re all on the same page then.
It Gets Better…
Over the years, a cottage industry appeared catering to older people looking for rejuvenation. Fortunately, the demand, driven partly by earlier research like the Endocine Reviews article, spurred researchers to dig deeper.
In one effort, researchers examined10 HGH’s effect on muscular strength in men over 50. During the study, subjects received hormone therapy for 6 months while measuring their bench press and squat strength throughout.
At the conclusion, the authors noted that “after 6 months of therapy, muscle strength in the bench press responsive muscles did not increase but showed a statistically significant increase in the leg press responsive muscles in the GH group.”
Every Bit Counts
Another study11 examined whether HGH benefits extended to men over 65, and found that “body weight did not change, but lean body mass increased, and fat mass decreased.”
The scientists concluded that “supplementation with rhGH does not augment the response to strength training.”
Hence, reconciling these two studies, it seems that the hormone’s strength increasing properties taper off after 50, and disappear by 65.
Even though there was ample proof of the hormone’s lean body mass and lean body fat capabilities, we didn’t understand its regenerative capacity until a later UCSF study.12
During their research, the scientists tried determining whether growth hormone supplementation improved wound healing in older populations.
The study authors concluded that “healthy older men who took growth hormone had enhanced reparative collagen deposition during the wound healing process.”
Can HGH Enhance Performance?
Of course, as with all dubiously advantageous substances, HGH made its way into bodybuilding and sports as a whole.
Flexing their creative muscles, some bodybuilders enhance HGH benefits and use the hormone conjunction with anabolic steroids to spur even greater muscle growth and improved performance.
Whatever the concoction, the goal is the same; faster, better, stronger.
But are the efforts likely to bear fruit? To what extent, if any, does HGH impact performance?
A foundational Brunel University study13 took an in-depth look at the hormone’s potential advantages and the underlying mechanisms.
As it turns out, the pulmonary gland isn’t the only source of HGH. Notably, sleep and exercise also play a role in hormone production.
Exercise, in particular, initiates an exercise-induced growth hormone response (EIGR), which is well recognized as enabling hormone production.
Trying to better understand EIGR, the researchers presupposed that the response operates by “afferent stimulation, nitric oxide, and lactate. Particularly, resistance training results in a significant EIGR.”
In fact, “evidence suggests that load and frequency are determining factors in the regulation of HGH secretion.” Even though the “insulin-like IGF-1 still contributes to protein synthesis.”
Further, the authors noted that EIGR has a “10 minute lactate threshold” at which the pulmonary gland begins secreting more HGH. Further, continued training above that threshold may “amplify the pulsatile release of HGH at rest, increasing it in the next 24 hours.”
To reach the proper lactate levels, researchers cited “high intensity exercise as effective in eliciting the benefits.”
Finally, the study cautions against overtraining, as the effects are unknown but may be detrimental
A later analyses14 further examined the tie between HGH and athletic performance in young physically fit subjects.
The researchers looked over 44 articles to get a bigger picture of the existing research. Their analysis mirrored earlier efforts.
Specifically, “lean body mass increased in growth hormone recipients compared with non-receiving participants, but strength and exercise capacity did not seem to improve.”
The researchers also expounded on the aforementioned Brunel University findings, focusing on exercise and its role on lactate levels. They found that “exercise raised lactate levels 2 to 3 times.”
The review concluded by finding that better physical performance was not one of the HGH benefits.
Reconciling the two pieces of research, it’s evident that exercise and resistance training in particular, induces lactate sourced EIGR. In turn, the response elicits greater lean body mass and body fat reduction, but not increased strength.
Clearly, there is ample anecdotal and scientific evidence of HGH benefits. While the majority of research concentrates on hormone deficient adults and the elderly, more data is emerging with fit, healthy, and younger subjects.
The newfound focus makes understanding HGH easier and will lead to safer and more effective use.