Seractide is a polypeptide hormone corresponding to thirty-nine amino acids of human corticotropin that differs from full-length human corticotropin at four positions. Seractide is potent endogenous melanocortin receptor 2 (MC ) agonist. Seractide stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also sex steroids (androgens). Seractide, was approved by FDA in 1978, but was never marketed. The Seractide, that was ultimately withdrawn by FDA in 2014 for safety reasons.

Glutamine is a non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from glutamic acid and ammonia. It is the principal carrier of nitrogen in the body and is an important energy source for many cells. Supplemental L-glutamine's possible immunomodulatory role may be accounted for in a number of ways. L-glutamine appears to play a major role in protecting the integrity of the gastrointestinal tract and, in particular, the large intestine. During catabolic states, the integrity of the intestinal mucosa may be compromised with consequent increased intestinal permeability and translocation of Gram-negative bacteria from the large intestine into the body. The demand for L-glutamine by the intestine, as well as by cells such as lymphocytes, appears to be much greater than that supplied by skeletal muscle, the major storage tissue for L-glutamine. L-glutamine is the preferred respiratory fuel for enterocytes, colonocytes and lymphocytes. Therefore, supplying supplemental L-glutamine under these conditions may do a number of things. For one, it may reverse the catabolic state by sparing skeletal muscle L-glutamine. It also may inhibit translocation of Gram-negative bacteria from the large intestine. L-glutamine helps maintain secretory IgA, which functions primarily by preventing the attachment of bacteria to mucosal cells. L-glutamine appears to be required to support the proliferation of mitogen-stimulated lymphocytes, as well as the production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma). It is also required for the maintenance of lymphokine-activated killer cells (LAK). L-glutamine can enhance phagocytosis by neutrophils and monocytes. It can lead to an increased synthesis of glutathione in the intestine, which may also play a role in maintaining the integrity of the intestinal mucosa by ameliorating oxidative stress. The exact mechanism of the possible immunomodulatory action of supplemental L-glutamine, however, remains unclear. It is conceivable that the major effect of L-glutamine occurs at the level of the intestine. Perhaps enteral L-glutamine acts directly on intestine-associated lymphoid tissue and stimulates overall immune function by that mechanism, without passing beyond the splanchnic bed. Glutamine is used for nutritional supplementation, also for treating dietary shortage or imbalance.

Bombesin (BN), a neuropeptide that originally was purified from the skin of the European frog (Bombina bombina). It has many biological effects including hormone release, stimulation of pancreatic enzyme secretion, gallbladder contraction and bronchoconstriction. Bombesin is a highly specific marker of neuroendocrine differentiation and thus a valuable tumor marker. It activates three different G-protein-coupled receptors known as BBR1, -2, and -3.

Antineoplaston (Phenylacetylglutamine) is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). The chemical structure of Antineoplaston AS2-5 corresponds to phenylacetylglutamine. Two synthetic derivatives of Antineoplaston A10 were named Antineoplaston AS2-1 and AS2-5. All antineoplaston formulations were submitted for Phase I clinical studies in advanced cancer patients. The treatment was free from significant side-effects and resulted in objective response in a number of advanced cancer cases. Antineoplastons are an experimental cancer therapy developed by S.R. Burzynski, MD, PhD. Chemically, antineoplastons are a mixture of amino acid derivatives, peptides, and amino acids found in human blood and urine. The developer originally isolated antineoplastons from human blood and later found the same peptides in urine. Urine was subsequently used because it was less expensive and easier to obtain. Since 1980, antineoplastons have been synthesized from commercially available chemicals at the Burzynski Research Institute. According to the developer, antineoplastons are part of a biochemical surveillance system in the body and work as "molecular switches." For the developer, cell differentiation is the key to cancer therapy. At the molecular level, abnormal cells that are potential cancer cells need to be "switched" to normal mode. Antineoplastons are the surveillance system that directs cancer cells into normal channels of differentiation. According to statements published by the developer, people with cancer lack this surveillance system because they do not have an adequate supply of antineoplastons.

Aceglutamide (INN, JAN) (brand name Neuramina), or aceglutamide aluminum (JAN, USAN) (brand name Glumal), also known as acetylglutamine, is a psychostimulant, nootropic, and antiulcer agent that is marketed in Spain and Japan. Aceglutamide functions as a prodrug to glutamine with improved potency and stability. Aceglutamide is used as a psychostimulant and nootropic, while aceglutamide aluminum is used in the treatment of ulcers. Aceglutamide can also be used as a liquid-stable source of glutamine to prevent damage from protein energy malnutrition.

Seractide is a polypeptide hormone corresponding to thirty-nine amino acids of human corticotropin that differs from full-length human corticotropin at four positions. Seractide is potent endogenous melanocortin receptor 2 (MC ) agonist. Seractide stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also sex steroids (androgens). Seractide, was approved by FDA in 1978, but was never marketed. The Seractide, that was ultimately withdrawn by FDA in 2014 for safety reasons.