intranasal delivery 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 2026-03-27. Numbers and descriptions here follow the published literature rather than marketing material.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
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.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
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.
As of 2008, no açaí products have been evaluated by the FDA, and their efficacy is doubtful. As of 2009, there is no scientific evidence that açaí consumption affects body weight, promotes weight loss or has any positive health effect.
Type 1 diabetes (T1D), or type 1 diabetes mellitus, is an autoimmune disease that occurs when the body's immune system destroys beta cells in the pancreas that produce the hormone insulin. Insulin is used by the body to store and convert blood sugar into energy. T1D results in high blood sugar levels in the body prior to treatment due to the lack of insulin. Common symptoms include frequent urination (polyuria), increased thirst (polydipsia), increased hunger (polyphagia), weight loss, and other changes. Additional symptoms may include blurry vision, tiredness, and slow wound healing (owing to impaired blood flow). While some cases take longer, symptoms usually appear within weeks to a few months. The cause of type 1 diabetes is not completely understood, but it is believed to involve an autoimmune attack caused by a combination of genetic and environmental factors. The underlying mechanism involves an autoimmune destruction of the insulin-producing beta cells in the pancreas. Diabetes is diagnosed by testing the level of sugar or glycated hemoglobin (HbA1C) in the blood. Type 1 diabetes can be distinguished from type 2 by testing for the presence of autoantibodies and/or declining levels/absence of C-peptide. C-peptide is a product cleaved from proinsulin in the production of insulin. In type 1 diabetes its levels are low or absent. In type 2 diabetes the blood levels are high, as insulin production is high due to insulin resistance. There is currently no known way to prevent type 1 diabetes. Treatment with insulin is required for survival.
Though these prompted the construction of the Somerset Coal Canal, and the formation of the Bristol Miners' Association, it was difficult to make mining profitable, and the mines closed after nationalisation in the 1940s. At the end of the 19th century the main industries were tobacco and cigarette manufacture, led by the dominant W.D. & H.O. Wills company, paper and engineering. The port facilities were migrating downstream to Avonmouth and new industrial complexes were founded there.
Sources: en.wikipedia.org
colorimeter Also chromometer. Any instrument used for color measurement based on optical comparison with standard colors, particularly a device used in colorimetry that measures the absorbance of specific wavelengths of light by a given solution in order to determine the concentration of a known solute in the solution, by application of the principle that solute concentration is directly proportional to absorbance.
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The transaction transferred Labcorp’s US-based biocompatibility, analytical testing, microbiological, and preclinical research services to NAMSA, enabling Labcorp to concentrate on its core preclinical drug development and chemical testing activities. In March 2026, Labcorp acquired select assets of Crouse Health, including assuming operations of Lab Alliance's 12 patient service centers.
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Sources: en.wikipedia.org
Liraglutide, a GLP-1 receptor agonist taken by subcutaneous injection once daily. Naltrexone/bupropion, a combination of naltrexone and bupropion taken by mouth twice daily. Orlistat is a lipase inhibitor taken by mouth three times daily with each main meal containing fat. Orlistat reduces intestinal fat absorption by inhibiting pancreatic lipase. Over the longer term, average weight loss on orlistat is 2.9 kg (6.4 lb). It leads to a reduced incidence of diabetes, and has some effect on cholesterol. However, there is little information on how it affects the longer-term complications or outcomes of obesity. It also inhibits absorption of fat soluble vitamins; vitamins A, D, E and K, so supplementation is needed for those on orlistat. Phentermine/topiramate combination of phentermine and topiramate taken by mouth once daily. Semaglutide, a GLP-1 receptor agonist taken by subcutaneous injection once weekly. Tirzepatide is a gastric inhibitory polypeptide (GIP) analog and a GLP-1 receptor agonist taken by subcutaneous injection once weekly. As of 2023, tirzepatide has shown the greatest weight reduction of medications. Phendimetrazine, diethylpropion, and phentermine are approved by the FDA for short term use, up to 12 weeks at a time.
Alpha-synuclein (aSyn) is a protein that in humans is encoded by the SNCA gene. It is a neuronal protein involved in the regulation of synaptic vesicle trafficking and the release of neurotransmitters. Alpha-synuclein is abundant in the brain, with smaller amounts present in the heart, muscles, and other tissues. Within the brain, it is primarily localized to the axon terminals of presynaptic neurons. There, it interacts with phospholipids and other proteins. Presynaptic terminals release neurotransmitters from specialized compartments called synaptic vesicles, a process essential for neuronal communication and normal brain function. In Parkinson's disease and related synucleinopathies, abnormal, insoluble forms of alpha-synuclein accumulate within neurons as inclusions known as Lewy bodies. Mutations in the SNCA gene are linked to familial forms of Parkinson's disease. During the process of seeded nucleation, alpha-synuclein adopts a cross-beta sheet structure characteristic of amyloid fibrils. The human alpha-synuclein protein consists of 140 amino acids. A fragment of alpha-synuclein, known as the non-amyloid beta component (NAC) of Alzheimer's disease amyloid, was initially isolated from an amyloid-rich brain fraction and shown to derive from a precursor protein named NACP. NACP was subsequently identified as the human homologue of synuclein from the electric ray genus Torpedo, leading to its renaming as human alpha-synuclein.
Chancellor Hunt says that cuts in public spending will cost "a great deal less" than allowing Russia to win. 25 April Labour pledges to renationalise most rail services within five years if it wins the next general election. The SNP's power-sharing deal with the Scottish Greens collapses. Shoplifting is reported to have hit a record high in 2023, with more than 430,000 offences recorded. This figure is up by more than one-third compared to 2022, and likely represents a fraction of the true number of incidents. In the High Court, Laurence Fox is ordered to pay £180,000 in libel damages to former Stonewall trustee Simon Blake and drag artist Crystal. The Environment Minister, Robbie Moore says "Additional time will be needed to efficiently and effectively roll out the schemes across the UK," as the Cash for Bottle deposit scheme is delayed until October 2027. Moroccan asylum seeker Ahmed Alid is convicted of the murder of Terence Carney, who was stabbed multiple times in an attack at Hartlepool in October 2023. Gary Roden resigns as the general manager of Co-op Live following a series of problems and delays at the venue. 26 April A trial begins of the first personalised melanoma vaccine, based on mRNA, the same technology as current COVID vaccines. Buckingham Palace announces that King Charles will resume his public duties from the following week after making good progress with his cancer treatment. An inquest into the 2020 Reading stabbings concludes they could have been avoided but for problems with the sharing of intelligence between authorities.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
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.