The purpose for which peptides are used determines their legality. For research purposes, it is perfectly all right for you get these compounds if you need to. But then, the discussion here is not about medical research but bodybuilding. It is less likely you are interested in them for the former purpose. Do note that it is illegal to buy and use peptides for purposes other than research.

Manipulation of somatostatin tone also affects the GH response to GHSs. When hexarelin was given to subjects in combination with somatostatin, the amount of GH released was significantly reduced. When arginine, a postulated inhibitor of somatostatin, was administered to older adults, a group proposed to have increased somatostatin tone, GH levels following the administration of GHRP-6 increased significantly, to levels seen in younger subjects.
IGF-1 causes hyperplasia and muscle and strength increase, looove IGF-1 (insulin-like growth factor). GHRP-6 causes your pituitary gland the secret growth hormones so you get a 'pulse' after each shot. The more shots, the more pulses you get which is why I split it up to 3 times a day. You feel amazing post-shot and also hungry as fuuu within 20 minutes, like a bottomless stomach. Also helps with fat-loss.
Finally, an exciting medical opportunity could be opened for synthetic GHRP to treat the threatening cancer-associated anorexia–cachexia syndrome in advanced-stage cancer patients. Although the mechanistic bases of this syndrome are not fully understood, it represents a major impediment for the course of chemotherapy. In a rodent model of cancer-bearing chemotherapy, GHRP-2 administration increased appetite/food intake and prolonged median survival time, which certainly suggests that GHRP-2 may improve the quality of life of cancer patients by correcting its nutritional and metabolic states.61 These data may also incite to further studies in the search for a potential niche for GHRP to counteract the catabolic states of prolonged critical illness, invasive surgeries, severe burn traumas, etc.
In more recent years, these data were further substantiated using again the TO-2 hamster DCM biomodel in which GHRP-2 reduced the progression of LV remodeling, dysfunction, and the ensued myocardial fibrosis by an antioxidant mechanism.36 The abovementioned myocardial fibrotic process amelioration reveals an additional potential use for GHRP in an unmet medical need. Chronic treatment with hexarelin in spontaneously hypertensive rats, in addition to decreasing ventricular hypertrophy, diastolic dysfunction, and high blood pressure, significantly reduced cardiac fibrosis by decreasing interstitial and perivascular myocardial collagen deposition and myocardial hydroxyproline content. Mechanistically, hexarelin treatment increased matrix metalloproteinase (MMP)-2 and MMP-9 activities and decreased myocardial mRNA expression of tissue inhibitor of metalloproteinase (TIMP)-1.37
Three of the submissions did not support the proposal highlighting the impact the change in scheduling would have on product currently on the market, industry, pharmacists and consumers. Two submissions noted that there has not been a history of concern with this combination of substances. One submission, referring to the NEJM article, believed that a lack of information about the study means that it cannot be relied upon as there is not a meaningful assessment of the results.
This peptide is a modified fragment of hGH which contains the portion of the molecule that is believed to be responsible for hGH’s anti-obesity effects. The peptide has been shown to increase fat burning without the increase in blood sugar and growth rate that has been seen with hGH itself. AOD 9604 has been deemed safe for chronic use by the FDA, receiving Human GRAS status in 2014. In addition to its utility as an anti-obesity peptide, AOD 9604 has been shown to have very favorable cartilage repair and regenerative properties, especially when paired with peptide BPC 157.

Just as the name suggests, GHRH helps to stimulate secretion of growth hormone. The duration of secretion induced will depend on the specific type of peptide that you use. An important thing to note here is that these substances are effective only to a limit. Exceeding the saturation dose, which may vary between individuals, will not improve the amount of HGH that is secreted. Below are a few peptides that fall in the GHRH group.

In this one you have a peptide with potential to stimulate GH release without resulting in issues associated with others. Just like GHRP-6, it both stimulates the pituitary and suppresses somatostatin. This is not the most powerful growth hormone releasing peptide. But neither causes your appetite to surge drastically nor your prolactin or cortisol levels to rise. These reasons make them a favorite for some users.

It is here that Growth Hormone Releasing Peptide 6, or Growth Hormone Releasing Hexapeptide comes into the picture. Also called as GHRP-6, it is a synthetic met-enkephalin analog. It includes unnatural D amino acids. It is instrumental in releasing growth hormone that helps in muscle recovery, strengthing of joints and tendons, and fat loss. It is distinct from Growth Hormone Releasing Hormone or GHRH which causes a higher amount of growth hormone to be secreted during the body normal secretion time. GHRP-6 on the other time will target a pulse and force the pituitary to release the growth hormone that is stored there. It helps a particular muscle group to achieve maximum growth.

When using any GHRH, it should always be remembered that positive results cannot be achieved overnight. These compounds act steadily over time, and the best results can be achieved slowly, and with a nutritious diet and a proper exercise regime. Also, these peptides are not sex-specific, so they do not have any androgenic effects. They can be used by women in the same dosages that men do.
These peptides are inhibitors of a protein called myostatin. Myostatin is secreted by muscle cells and acts to essentially block the development of new muscle fibers and, thus, the development of lean muscle mass. In fact, individuals who have mutations in the gene coding for this protein have significantly more muscle mass and enhanced strength. The administration of follastatin peptides can generate enhanced muscle mass and strength, and has been found especially useful in patients suffering from muscle-wasting diseases or who have difficulty gaining muscle.

GH secretagogues differ from exogenous rHGH in their effects primarily because endogenous GH contains all five isoforms of growth hormone, whereas exogenous GH contains only the 20 kilodalton isoform. Different isoforms affect tissues in discreet ways that the 20 kDa isoform cannot. Administration of GH secretagogues causes a pulse-release of GH from the pituitary which is cleared from the body within a few hours. This does not significantly raise plasma insulin-like growth factor 1 (IGF-1) levels.[citation needed]