1. Lowers Blood Sugar
Research in animals has revealed that the c-terminal end of hGH is primarily responsible for the protein’s hypoglycemic (lowering blood sugar) effects. Testing of at least six different fragments derived from this section of hGH has shown that fragment 176-191 is the most effective synthetic derivative of hGH for lowering blood sugar levels. This effect is secondary to a sustained increase in plasma insulin levels. There is some interest in using fragment 176-191 as a treatment for both prediabetes and type 2 diabetes.
2. Fat Burning And Weight Loss
Fragment 176-191 has earned the nickname of “lipolytic fragment” because testing in mice has revealed the peptide to have substantial fat burning and weight loss properties. It is thought that this action is mediated through an increase in production of beta-3 adrenergic receptors (β3-AR or ADRB3). Agonist action at ADRB3 is known to directly increase fat burning in adipose tissue and is also responsible for thermogenesis in skeletal muscle. Mice that have been genetically modified to produce no ADRB3 do not respond to the lipolytic effects of hGH or fragment 176-191.
Studies show that the increased fat burning associated with fragment 176-191 directly correlates with energy expenditure and thus weight reduction, leading to a nearly 50% reduction in weight gain in obese animals over a three-week course. Interestingly, the weight loss effects were seen only in obese mice, with lean mice maintaining normal body weight, on average, even when exposed to fragment 176-191. These findings indicate that there are secondary regulatory pathways for lipolysis that override ADRB3 function when body weight is at or near ideal, opening up areas for additional research into energy homeostasis.
3. Promotes Cartilage Regeneration
Though fragment 176-191 is primarily of interest for its lipolytic properties, the peptide is under investigation for other possible benefits. Of note, a 2015 article out of Korea revealed that fragment 176-191 may be able to potentiate the effects of hyaluronic acid injections in promoting cartilage regeneration. Studies in rabbits indicated that weekly injections of fragment 176-191 increase laboratory measures of cartilage growth and that co-administration of the peptide with hyaluronic acid (HA) produces even more substantial effects. Similarly, the study found that fragment 176-191, both alone and in combination with HA, reduces disability associated with osteoarthritis. There is hope that this may lead to advanced therapies for osteoarthritis and may even eliminate the need for surgery in certain settings.