Best Research Peptides

Protein-protein interactions are fundamental mediators of cell growth, regeneration, and death pathways. These interactions have served as important targets in the pharmaceutical industry for nearly twenty years now. Recently, however, the smaller size of peptides and their relatively simply conformational structures has made them promising candidates for the development of therapeutics that can target challenging binding sites both outside of (on the surface of) and inside of cells. In fact, some peptides can even penetrate the nuclear and mitochondrial membranes to alter DNA expression patterns. As a result of these recent efforts, over 60 peptides have been approved by global regulatory agencies while hundreds more have helped to advance the scientific understanding of cell physiology. This was supposed to be the era of DNA technology in the biological sciences, but it would be unsurprising if future scientists look back on these days as the era of peptide technology[1].

There are too many peptides under active research to keep track of them all, a fact that makes listing the “best research peptides” a difficult task. After all, just coming up with criteria by which to judge these wonders of modern research seems a daunting task. To that end, the list that follows isn’t so much of an absolute “best” list as it is a list of the peptides that have garnered the most attention or which have provided the most robust insights into cellular biology. In the end, this list is just a sampling of some of the best research peptides currently under investigation. For anyone interested in the science of peptides, this guide might give some direction or pique interest in the world of peptide science.

Why Care About Peptides?

Before talking about the peptides that have earned a spot on the “Best Research Peptides” list, it is worth addressing why science has recently invested so much into these small molecules. Simply put, peptide-receptor interactions are at the core of both normal and pathogenic biology. Proteins, and especially peptides, are signaling molecules for much of the communication that occurs between cells and within individual cells. The information that they convey both from cell to cell and within a cell can alter everything from receptor signaling and hormone production to DNA expression and even whether a cell goes down the apoptosis (programmed cell death) pathway. Abnormal peptide-receptor interactions drive signaling changes within cells that can exacerbate or ameliorate responses to infection, inflammation, cancer, cardiovascular disease, neurodegeneration, food intake, growth signals, and so much more. In short, peptide-receptor interactions control much of what goes on inside of the body. Understanding these interactions is, in and of itself, important. However, the ability to influence these interactions may yield solutions to some of life’s most vexing disease conditions and may even, one day, open the doorway to longevity beyond imagination. Here is a look at some of the peptides that have helped to advance our understanding of mammalian biology and have even guided the development of some therapeutics.

Adipotide

Adipotide kills fat cells by targeting the blood vessels that supply nutrients to them. It was one of the first peptides discovered to have tissue-specific targeting effects. As such, it has opened research avenues helping science to understand how molecules with particularly toxic action might be targeted to specific tissues while sparing others. Research shows that adipotide’s specificity makes it one of the most potent fat-loss molecules yet discovered. In mouse models, adipotide led to a 20% weight loss without a change in diet. As a bonus, it is known to improve glucose sensitivity and reduce insulin resistance.

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BPC-157

BPC-157 is one of the most heavily researched compounds in the history of peptides. Originally isolated as BPC (body protection compound) from the human GI tract, BPC-157 has demonstrated remarkable healing properties. Research has shown it to have effects on blood vessel growth, nitric oxide generation, immune system function, hormone regulation, blood coagulation, and even gene expression patterns. BPC-157 is a powerful antioxidant that protects everything from cardiac tissue to honey bees. It is of particular interest in the treatment of inflammatory bowel disease and for improving tendon growth and repair following injury.

GHK-Cu

Like BPC-157, GHK-Cu finds itself on the list of best research peptides because of its multiple mechanisms of action, robust evidentiary support, and its influence on peptide research in general. GHK-Cu was originally isolated from human blood plasma and has since been found to have important wound healing properties. It also alters immune function, suppresses inflammation, protects against free radical damage, reduces pain perception, influences nerve growth, and alters DNA expression patterns for up to 31% of human genes. GHK-Cu is widely studied in anti-aging research because, in mouse models, it has been shown to reverse cognitive impairment and slow the progression of many diseases associated with aging. It is also heavily studied in the cosmetic industry and has made its way into several skin creams and lotions because studies show that it can reduce wrinkles and pigmentation, restore elasticity, promote hair growth, lessen the appearance of sun damage, and improve the overall quality of skin.

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KPV

KPV is one of the smallest peptides known and is a derivative of alpha-melanocyte stimulating hormone. It has been shown in animal trials to have significant anti-inflammatory effects and has been intensely studied for the treatment of inflammatory bowel disease. Research in mice shows that oral delivery of KPV to the intestine can reduce TNF-alpha levels locally, avoiding the systemic side effects that result from injecting TNF-alpha inhibitors. KPV doesn’t only reduce inflammation by interfering with TNF-alpha signaling, however. KPV was one of the first molecules to demonstrate that small peptides can penetrate both the cell membrane and the nucleus itself to regulate DNA expression patterns. It is known to reduce NFκB activity, which alters immune system responses and helps to reduce inflammation. KPV has been one of the peptides that has helped to not only treat targeted disease conditions, but to also expand our understanding of how cell signaling is controlled.

Melanotan-2/PT-141

Melanotan-2 and its derivative PT-141 have gained a lot of attention for their abilities to control everything from hunger to sexual desire. Both are derivatives of melanotan, which itself is a derivative of naturally occurring melanocyte-stimulating hormone. These peptides have been instrumental in exploring the properties of the melanocortin receptor system, a lesser-known hormone regulatory system that is now known to be important in hunger, sexual behavior, food preference, skin pigmentation, and more. They have additionally been instrumental in helping scientists to understand how specific parts of larger proteins can possess individual functions and how deriving smaller peptide fragments from larger parent proteins can lead to more specific interactions as well as changes in properties like absorbability and effective routes of administration. Both peptides have been shown to stimulate sexual arousal in men as well as women. They can also generate skin pigmentation by stimulating melanogenesis. Though once pursued as potential sunless tanning agents, such avenues have been generally abandoned in favor of the peptides’ more potent sexual properties.

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NAD+

NAD, the oxidized form of NADH, carries electrons from one biochemical reaction to another and serves in cell-to-cell communication. Research shows that it is released naturally in the blood vessels, bladder, intestine, and brain. It’s most important role, however, is in the function of mitochondria. NAD helps to protect mitochondria from the dysfunction of age and prolongs the life of individual cells. By activating SIRT 1 in mitochondria, NAD regulates stress and inflammatory responses.

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Semax

Semax is no longer one of the most heavily researched peptides on the list of best research peptides, but it nonetheless deserves recognition for being one of the early peptides to jumpstart research in the area. Semax is a synthetic peptide derived from adrenocorticotropic hormone. Originally valued for its ability to protect neurons and even enhance cognition, Semax is now understood to influence levels of brain-derived neurotrophic factor (BDNF). As such, Semax has opened the door to greater understanding of the factors that govern neuron growth, development, differentiation, and survival. It has helped science to better understand learning and long-term memory retention[2]. Used in Russia in the treatment of stroke, there has been interest in the ability of Semax to boost cognitive function in healthy brains and thus serve as a nootropic.

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Sermorelin

Sermorelin is just one member of a large class of peptides known as growth hormone secretagogues. As the most famous member of this group of peptides, sermorelin has gained a great deal of research interest since its discovery almost 50 years ago. By stimulating growth hormone release, sermorelin has been shown to affect bone density, muscle building, renal function, brain function, scar formation, wound healing, and sleep quality. Research shows that it can even fight the effects of dementia. Touted by some as the closest humanity has come to discovering the fountain of youth, sermorelin has a strong following in anti-aging research where it has been shown to slow and even reverse the effects of somatopause. Other peptides that increase growth hormone levels include GHRP-2, GHRP-6, CJC-1295, Hexarelin, Ipamorelin, and more. Each of these peptides has an extensive research profile.

The Best Research Peptides: Moving Forward

The peptides above are mostly second and third generation peptides, which is to say many of them are derivatives of earlier peptides or were developed by looking at the structure and actions of existing peptides. They have built upon the research of peptides that came before them and have spawned advances in our understanding of cell regulation. Even now, derivatives of these peptides are being developed to continue the relentless pursuit of biological knowledge. That’s not to say that these peptides are no longer in vogue, however. In fact, many of the peptides listed above are still hotly researched and continue to provide insight into biological signaling. Some of these peptides will remain on the best research peptides for decades to come while others will give way to newer derivatives with enhanced specificity, improved receptor binding, and a host of other properties.