Pro-Gly-Pro comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-01-18. Numbers and descriptions here follow the published literature rather than marketing material.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
=== Regional groups === Head and neck – includes everything above the thoracic inlet Upper limb – includes the hand, wrist, forearm, elbow, arm, shoulder Thorax – the region of the chest from the thoracic inlet to the thoracic diaphragm Human abdomen to the pelvic brim or to the pelvic inlet The back – the spine and its components, the vertebrae, sacrum, coccyx, intervertebral disks Pelvis and perineum – the pelvis consists of everything from the pelvic inlet to the pelvic diaphragm; the perineum is the region between the sex organs and the anus Lower limb – everything below the inguinal ligament, including the hip, the thigh, the knee, the leg, the ankle, the foot
Instead, the ionic current from an action potential at one node of Ranvier provokes another action potential at the next node; this apparent "hopping" of the action potential from node to node is known as saltatory conduction. Although the mechanism of saltatory conduction was suggested in 1925 by Ralph Lillie, the first experimental evidence for saltatory conduction came from Ichiji Tasaki and Taiji Takeuchi and from Andrew Huxley and Robert Stämpfli. By contrast, in unmyelinated axons, the action potential provokes another in the membrane immediately adjacent, and moves continuously down the axon like a wave.
mab: whole monoclonal antibody Fab: fragment, antigen-binding (one arm) F(ab')2: fragment, antigen-binding, including hinge region (both arms) Fab': fragment, antigen-binding, including hinge region (one arm) Variable fragments: scFv: single-chain variable fragment di-scFv: dimeric single-chain variable fragment sdAb: single-domain antibody BsAb: bispecific monoclonal antibody: 3funct: trifunctional antibody BiTE: bi-specific T-cell engager This list of over 500 monoclonal antibodies includes approved and investigational drugs as well as drugs that have been withdrawn from market; consequently, the column Use does not necessarily indicate clinical usage. See the list of FDA-approved therapeutic monoclonal antibodies in the monoclonal antibody therapy page.
The word spectrograph had become part of the international scientific vocabulary by 1884. Early spectrometry devices that measured the mass-to-charge ratio of ions were called mass spectrographs which consisted of instruments that recorded a spectrum of mass values on a photographic plate. A mass spectroscope is similar to a mass spectrograph except that the beam of ions is directed onto a phosphor screen. A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an oscilloscope. The use of the term mass spectroscopy is now discouraged due to the possibility of confusion with light spectroscopy. Mass spectrometry is often abbreviated as mass-spec or simply as MS. Modern techniques of mass spectrometry were devised by Arthur Jeffrey Dempster and F.W. Aston in 1918 and 1919 respectively. Sector mass spectrometers known as calutrons were developed by Ernest O. Lawrence and used for separating the isotopes of uranium during the Manhattan Project. Calutron mass spectrometers were used for uranium enrichment at the Oak Ridge, Tennessee Y-12 plant established during World War II. In 1989, half of the Nobel Prize in Physics was awarded to Hans Dehmelt and Wolfgang Paul for the development of the ion trap technique in the 1950s and 1960s.
=== Stain etching === It is possible to obtain porous silicon through stain-etching with hydrofluoric acid, nitric acid and water. A publication in 1957 revealed that stain films can be grown in dilute solutions of nitric acid in concentrated hydrofluoric acid. Porous silicon formation by stain-etching is particularly attractive because of its simplicity and the presence of readily available corrosive reagents; namely nitric acid (HNO3) and hydrogen fluoride (HF). Furthermore, stain-etching is useful if one needs to produce a very thin porous Si films. A publication in 1960 by R. J. Archer revealed that it is possible to create stain films as thin as 25 Å through stain-etching with HF-HNO3 solution.
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== Eponym == Donohue syndrome was first identified in 1948 by Canadian pathologist William L. Donohue (1906–1985). The name leprechaunism has been largely abandoned because of the perception of the name by some parents of patients as insulting.
It contended that the benefits were substantial and that even if bacteria became resistant, new antibiotics would soon be developed, and there was no evidence that bacterial resistance in animals impacted human health. The Netherthorpe committee's conclusions were undermined by new research even before they were published, and the committee was recalled to reconsider the issue in 1965. New studies had shown that bacteria were not only able to inherit the genes for antibiotic resistance, but they could also communicate them to each other. In 1967, a multiresistant strain of E. coli killed fifteen children in the UK. The use of antibiotics in animals for nontherapeutic use was banned there in 1971. Many other European countries soon followed. When Sweden acceded to the European Union (EU) in 1995, a total ban on antibiotic growth promoters (AGPs) had been in place there for ten years. This would be superseded by more relaxed EU rules unless Sweden could demonstrate scientific evidence in favour of a ban. Two Swedish scientists, Anders Franklin and Christina Greko, and two Danish scientists, Frank Aarestrup and Henrik Wegener, took up the fight. The odds seemed against them but this coincided with the United Kingdom BSE outbreak, which resulted in intense political pressure. In December 1996, the European Parliament's Standing Committee on Health and Welfare voted to ban the use of AGPs. The EU went further and recommended broad restrictions on the use of antibiotics. These regulations were adopted in 2019 and took effect in 2022.
The company is well known for its advertising catchphrase "Pizza! Pizza!", which was introduced in 1979. The phrase refers to two pizzas being offered for the comparable price of a single pizza from competitors. Initially, the pizzas were served in a single long package (a piece of corrugated cardboard in 2-by-1 proportions, with two pizzas placed side by side, then slid into a form-fitting paper sleeve that was folded and stapled closed). In 1988, they introduced a square deep-dish pizza called “Pan! Pan!”. Customers could purchase the “Pan! Pan!” pizzas as part of the 2-for-1 deal or mix and match with one pan pizza and one original round pizza. Little Caesars has since discarded the unwieldy packaging in favor of typical pizza boxes. For a time, in addition to pizza, the menu included hot dogs, chicken, sub sandwiches, shrimp, and fish. In the mid-1980s, Little Caesars opened several family entertainment centers in the Detroit and Chicago area with Little Caesars branding, initially being named Little Caesars Family Fun Pizzeria. Several of these locations were formerly Chuck E. Cheese's Pizza Time Theatre locations owned by Mike Ilitch. Little Caesars Family Fun Pizzeria would be rebranded into Caesarland by the mid-1990s, which featured play places similar to Discovery Zone. Caesarland would operate until 2011, when the last locations would close due to declining business. In 1997, the chain introduced shaker boards to advertise its "Hot-N-Ready Pizza", a large pepperoni pizza sold for $5.
== Use and effects == The 25-NB drugs are inactive orally and instead are typically used sublingually, buccally, by insufflation, or sometimes via inhalation. They are typically employed at doses in the range of 50 to 1,500 μg, variable depending on the specific drug, and have durations in the range of 3 to 12 hours. The table below provides an overview of the major 25-NB drugs and their properties. Conventionally, 25-NB have been known to be orally inactive due to extensive first-pass metabolism. However, an orally active N-benzylphenethylamine with an atypical chemical structure known as BMB-202 has since been identified and is under development for potential medical use. It is predicted to have a fast onset and a short duration of 1 to 2 hours in humans.
Sources: en.wikipedia.org
chemotaxis A directed, non-random change in the movement of a molecule, cell, or organism in response to a chemical stimulus, e.g. towards or away from an area with a high concentration of a particular chemical compound.
In France, Olivier Besancenot, the Revolutionary Communist League candidate in the 2007 presidential election, received 1,498,581 votes (4.08%), double that of the candidate from the French Communist Party candidate. The party abolished itself in 2009 to initiate a broad anti-capitalist movement within a new party called the New Anticapitalist Party, whose stated aim is to "build a new socialist, democratic perspective for the twenty-first century." In Germany, The Left was founded in 2007 out of a merger of the Party of Democratic Socialism (PDS) and the Labour and Social Justice – The Electoral Alternative (WASG), a breakaway faction from the Social Democratic Party of Germany (SPD) which rejected then-SPD leader and German Chancellor Gerhard Schröder for his Third Way policies. According to Kate Hudon, these parties adopted policies to appeal to democratic socialists, greens, feminists and pacifists. Former SPD chairman Oskar Lafontaine has noted that the founding of The Left in Germany has resulted in emulation in other countries, with several Left parties being founded in Greece, Portugal, Netherlands and Syria. Lafontaine claims that a de facto British Left movement exists, identifying the Green Party of England and Wales as holding similar values. Nonetheless, a democratic socialist faction remains within the SPD.
A denturist in the United States and Canada, clinical dental technologist in the United Kingdom and Ireland, dental prosthetist in Australia, or a clinical dental technician in New Zealand is a member of the oral health care team and role as primary oral health care provider who provides an oral health examination, planning treatment, takes impressions of the surrounding oral tissues, constructs and delivers removable oral prosthesis treatment (including dentures and partial dentures) directly to the patient.
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Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.