This review summarizes how GHRPs and CJC-1295 have been studied synergistically in growth hormone replacement, as seen in animal research models.

The growth hormone is one of the important hormones in the body. It increases chondrocytes (cartilage cells), resulting in bone growth. It also increases muscle mass by stimulating the differentiation and proliferation of myoblasts (muscle cells) and is involved in protein build-up in tissues.

However, growth hormone secretion declines with age. Stimulating increased growth hormone production may help prevent several deteriorating structural and functional characteristics associated with old age, ultimately prolonging long qualitative life.

Growth Hormone-Releasing Peptides (GHRPs)

GHRP is an acronym for growth hormone-releasing peptides. Though they do not structurally resemble growth hormone-releasing hormone (GHRH), they were developed to perform functions similar to GHRH. GHRH is a natural hormone produced in the hypothalamus. It stimulates the anterior pituitary gland to produce growth hormone, which has a lot of benefits in the body, as discussed later. GHRPs are synthetic peptides that have the potential to act on certain receptors in either the anterior pituitary gland or the hypothalamus to block the effect of hormones that inhibit the production of growth hormones. This activity enhances growth hormone production.

Certain GHRPs have been examined in animal studies, especially rats, and have been suggested to stimulate growth in rats. They include GHRP-6, GHRP-1, GHRP-3, and Hexarelin. GHRPs appear to be age-dependent, and their effects may increase from birth to mid-fifties before finally declining gradually with older age. Though synthetic hormones, their effects have the potential to be stronger than GHRH, and when used synergistically, they may produce optimal growth hormone production.

GHRPs Mechanism of Action

Unlike GHRH, studies suggest that GHRPs release growth hormone via a Ca2+-dependent, cyclic AMP-independent mechanism. Certain animal studies also suggest that they may inhibit somatostatin, the growth hormone inhibitory hormone at the pituitary and hypothalamic levels, through a GHRH-mediated mechanism.

CJC-1295 Peptide

Unlike GHRPs, CJC-1295 (drug affinity complex: growth hormone-releasing factor {DAC: GRF}) is a synthetic analog of growth hormone. It resembles growth hormone structurally and mimics the action of growth hormone. Studies suggest its potential to bind readily to albumin in the blood, increasing duration of time in circulation before it breaking down. It has an estimated half-life of 7-8 days.

CJC-1295 has four amino acids different from growth hormone-releasing hormone, making it resistant to proteolytic inactivation by dipeptidyl peptidase IV (DPP-IV). All these structural attributes of CJC-1295 form the potential to stimulate a sustained, markedly increased production of serum growth hormone and insulin-like growth factor 1 (IGF-I).

CJC-1295 Peptide Mechanism of Action

CJC-1295 is a growth hormone-releasing hormone mimetic. It has been studied for its potential to stimulate growth hormone production in the anterior pituitary gland, which acts on several body tissues via the insulin-like growth factor 1(IGF-I). However, unlike GHRPs, it has not been established to inhibit the growth hormone inhibitory hormone somatostatin; both GHRP and CJC- 1295 combined may achieve an increased anabolic effect.

GHRPs and CJC-1295 Peptide

Growth hormone secretion declines with age in both sexes, which is one reason for the structural and functional deterioration in the human body that comes with old age. Growth hormone replacement therapy may help alleviate this deterioration. Theoretically, it can help reverse the deteriorating symptoms that come with aging, and it has also been postulated to be of great importance in improving muscle strength and functional performance. In children with low growth hormone levels or dwarfs, it may be helpful in bone growth.

Excessive growth hormone is detrimental to the body, as it can cause diabetes and certain abnormal conditions like acromegaly, in which the hands and feet are abnormally large. Scientists developed GHRPs as possible growth hormone replacement therapies due to their potential to cause a pulsatile rather than prolonged elevation in growth hormone levels. Researchers report the negative feedback mechanism remains well intact.

If GHRP is combined with CJC 1295, studies suggest it may produce a synergistic effect on growth hormone release that becomes beneficial to the body. Therefore the supplementation of both substances may be more effective than either alone. The possible effects of these peptides under investigation are summarized here:

  • Potentially maintain and build healthy tissues in the brain, lungs, kidneys, and other organs
  • Potentially support the rate of healing after an injury
  • Potentially increase muscle mass
  • Potentially maintain young, healthy skin
  • Potentially slow down the aging process
  • Potentially improve bone density in children
  • Potentially increase exercise capacity
  • Potentially reduce body fat.

Growth Hormones and GHRPs/CJC-1295 Peptides

When produced in excess, growth hormones can lead to some unwanted effects, such as:

  • Acromegaly (abnormally large size of the face, hands, and feet)
  • Joint pain
  • Risk of diabetes
  • Fatigue
  • Gynecomastia (enlarged breasts) in men

To mitigate the possible side effects of overexpression of growth hormones in the body, GHRPs may combine with CJC-1295 for potentially optimal effects. They may mimic growth hormones by producing hormones in a pulsatile manner, regulating the amount of growth hormone in the circulation.

GHRPs and CJC-1295 appear to act physiologically to increase hormone production with minimal side effects. Researchers are still investigating the full action and effects of these peptides, and further studies are needed to validate any theories. As explained above, they have great potential for future therapies in ameliorating aging-related problems. 


The peptides available here are strictly for research and laboratory purposes only, and are not approved for human consumption.


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