If you have been reading about Selank and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-10-29. Numbers and descriptions here follow the published literature rather than marketing material.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
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.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
=== Surgical gloves === During his surgical career, Edlich and his team of scientists made important scientific contributions that have protected health care workers as well as operating room personnel. His studies on the toxicity of corn starch became a catalyst for the development of powder-free gloves. His scientific investigation proved conclusively that cornstarch was a dangerous foreign body that potentiated wound infection and was a vector for the latex allergy epidemic. On September 24, 2008, Edlich and eleven health professionals submitted a Citizen's Petition to the FDA to ban cornstarch on medical gloves (FDA-2008-P-0531). On February 3, 2011, the FDA prepared a Federal Register on the safety and performance of medical gloves with cornstarch, in which healthcare professionals had 60 days to make comments that ultimately led to the FDA's final decision regarding banning cornstarch on medical gloves. Edlich's studies on a new powder-free double-glove puncture indication system support the use of this double-glove system in surgical procedures in an effort to prevent the spread of deadly blood-borne viral infection (Molnlycke Healthcare, LLC, Norcross, Georgia)
=== Personal nutrition === Personalized dietary requirements for an individual's nutritional needs has been linked to the prevention of diseases. As such, eating nutritious food is paramount to living a healthy life. 3D printed food can provide the control necessary to put a custom amount of protein, sugar, vitamins, and minerals into the foods we consume. Another area in customized food is elderly nutrition. The elderly sometimes cannot swallow foods, and as such require a softer pallet. However, these foods are often unappealing causing some individuals not to eat what their bodies' nutritional needs require. 3D printed food can provide a soft and aesthetically pleasing food in which the elderly can consume their bodies' dietary requirements. In October 2019, startup company Nourished 3D prints personalized nutritional gummies from 28 different vitamins. Individuals take a survey, then based on their answers, a personalized nutritional gummy is printed for that individual.
However, the data were insufficient to support a role for FFAR3 in the release of leptin from cultured human fat tissues or the fat tissue of intact animals. The role of FFAR3 stimulation of leptin release in appetite suppression and obesity needs further study.
Sources: en.wikipedia.org
Aside from its association with trees, A. roeperi shares its most significant ecological interactions with the granulate ambrosia beetle Xylosandrus crassiusculus. As in other ambrosia beetles, the fungus benefits from the opportunity for dispersal via the insect's mycangium, which in X. crassiusculus consists of a spacious mesonotal pouch. According to the current understanding of this symbiosis, when beetles emerge from pupae, their mycangia are inoculated with ambrosial fungi, and special gland cells flanking the mycangium begin to secrete compounds that promote their growth over that of assorted commensals. When the beetles colonize a new tree, the fungus growing in the cuticular pouch is introduced to the walls of the new gallery, glandular activity stops, and the mycangium ceases to act as a selective organ. The larvae and adults feed exclusively upon the conidia produced along the walls of the gallery, through which the beetles meet all of their nutritional requirements. (This feature differentiates ambrosia beetles from bark beetles, which typically feed on the phloem and, though they may eat and/or disperse some fungi, can generally survive on wood alone.) Structures possibly comprising lipid bodies can be seen within the cytoplasm of A. roeperi spores and conidiogenous cells, which may represent a means of storage for energy-rich compounds that it then imparts to the feeding beetles. Though trees and insects are perhaps the most pivotal points of Ambrosiella ecology, the galleries in which A.
Bruck syndrome is characterized as the combination of arthrogryposis multiplex congenita and osteogenesis imperfecta. Both diseases are uncommon, but concurrence is extremely rare which makes Bruck syndrome very difficult to research. Bruck syndrome is thought to be an atypical variant of osteogenesis imperfecta most resembling type III, if not its own disease. Multiple gene mutations associated with osteogenesis imperfecta are not seen in Bruck syndrome. Many affected individuals are within the same family, and pedigree data supports that the disease is acquired through autosomal recessive inheritance. Bruck syndrome has features of congenital contractures, bone fragility, recurring bone fractures, flexion joint and limb deformities, pterygia, short body height, and progressive kyphoscoliosis. Individuals encounter restricted mobility and pulmonary function. A reduction in bone mineral content and larger hydroxyapatite crystals are also detectable Joint contractures are primarily bilateral and symmetrical, and most prone to ankles. Bruck syndrome has no effect on intelligence, vision, or hearing.
=== Elderly === For the elderly, benzodiazepines have reduced benefits and increased risks. They are listed as a potentially inappropriate medication for older adults by the American Geriatrics Society. The elderly are at an increased risk of dependence and are more sensitive to the adverse effects such as memory problems, daytime sedation, impaired motor coordination, and increased risk of motor vehicle accidents and falls, and an increased risk of hip fractures. The long-term effects of benzodiazepines and benzodiazepine dependence in the elderly can resemble dementia, depression, or anxiety syndromes, and progressively worsens over time. Adverse effects on cognition can be mistaken for the effects of old age. The benefits of withdrawal include improved cognition, alertness, mobility, reduced risk of incontinence, and a reduced risk of falls and fractures. The success of gradual-tapering benzodiazepines is as great in the elderly as in younger people. Benzodiazepines should be prescribed to the elderly only with caution and only for a short period at low doses. Short to intermediate-acting benzodiazepines are preferred in the elderly such as oxazepam and temazepam. The high potency benzodiazepines alprazolam and triazolam and long-acting benzodiazepines are not recommended in the elderly due to increased adverse effects. Nonbenzodiazepines such as zaleplon and zolpidem and low doses of sedating antidepressants are sometimes used as alternatives to benzodiazepines.
Sources: en.wikipedia.org
which means that the divergence of the velocity field is zero everywhere. Physically, this is equivalent to saying that the local volume dilation rate is zero, hence a flow of water through a converging pipe will adjust solely by increasing its velocity as water is largely incompressible.
Calcitriol is a hormone and the active form of vitamin D3, normally made in the kidney. It is also known as or 1,25-dihydroxycholecalciferol (1,25-(OH)2D3). It binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. Calcitriol increases blood calcium mainly by increasing the uptake of calcium from the intestines. Calcitriol can be given as a medication for the treatment of osteoporosis, osteomalacia, familial hypophosphatemia, low blood calcium due to hypoparathyroidism, and low blood calcium and hyperparathyroidism due to kidney disease. It can be taken by mouth or by injection into a vein. Excessive amounts or intake can result in weakness, headache, nausea, constipation, urinary tract infections, and abdominal pain. Serious side effects may include high blood calcium and anaphylaxis. Calcitriol was identified as the active form of vitamin D3 in 1971 and the drug was approved for medical use in the United States in 1978. It is available as a generic medication. In 2023, it was the 249th most commonly prescribed medication in the United States, with more than 1 million prescriptions. It is on the World Health Organization's List of Essential Medicines.
In the United States, the Federal Food, Drug, and Cosmetic Act defines what substances, known as legend drugs, require a prescription for them to be dispensed by a pharmacy. The federal government authorizes physicians (of any specialty), physician assistants, nurse practitioners and other advanced practice nurses, veterinarians, dentists, and optometrists to prescribe any controlled substance. They are issued unique DEA numbers. Many other mental and physical health technicians, including basic-level registered nurses, medical assistants, emergency medical technicians, most psychologists, and social workers, are not authorized to prescribe legend drugs. The federal Controlled Substances Act (CSA) was enacted in 1970. It regulates manufacture, importation, possession, use, and distribution of controlled substances, which are drugs with potential for abuse or addiction. The legislation classifies these drugs into five schedules, with varying qualifications for each schedule. The schedules are designated schedule I, schedule II, schedule III, schedule IV, and schedule V. Many drugs other than controlled substances require a prescription. The safety and the effectiveness of prescription drugs in the US are regulated by the 1987 Prescription Drug Marketing Act (PDMA). The Food and Drug Administration (FDA) is charged with implementing the law. As a general rule, over-the-counter drugs (OTC) are used to treat a condition that does not need care from a healthcare professional if have been proven to meet higher safety standards for self-medication by patients.
== Growth and morphology == Rhizopus oryzae grows quickly in optimal temperatures, at 1.6 mm per hour (nearly 0.5 μm per second - enough to be able to directly visualize hyphal elongation in real-time under the microscope). R. oryzae can grow in temperature of 7 °C to 44 °C and the optimum growth temperature is 37 °C. There is very poor growth from 10 °C to 15 °C and negligible growth at 45 °C. There is substantial growth in media containing 1% NaCl, very poor growth at 3% NaCl, and none at 5% NaCl. R. oryzae favors slightly acidic media. Good growth is observed at a pH of 6.8; in the range of 7.7-8.1, there is very poor growth. Most amino acids—with the exception of L-valine—promote R. oryzae growth, with L-tryptophan and L-tyrosine being the most effective. It also grows well on mineral nitrogen sources, except nitrate, and can utilize urea. Rhizopus oryzae has variable sporangiosphores. They can be straight or curved, swollen or branched, and the walls can be smooth or slightly rough. The colour of sporangiosphores range from pale brown to brown. Sporangiosphores grow between 210-2500 μm in length and 5-18 μm in diameter. The sporangia in R. oryzae are globose or subglobose, wall spinous and black when mature, 60-180 μm in diameter. They can be distinguishable from Rhizopus stolonifer as they have smaller sporangia and spores. The optimal conditions for sporangium production are temperatures between 30 °C to 35 °C and low water levels.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.