A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-07-28 and is reviewed periodically as new material appears.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
== Description == Consider a ligand receptor binding system. Ligand with a concentration L associates with a receptor of concentration or availability R to form a ligand-receptor complex with concentration RL. The binding potential is then the ratio ligand-receptor complex to free ligand at equilibrium and in the limit of L tending to 0, and is given symbol BP:
== Regulatory scrutiny == The Royal Australian College of General Practitioners (RACGP) raised concerns in 2023 about telehealth services using remote questionnaires to prescribe GLP-1 receptor agonists, questioning whether such methods provided adequate clinical assessment. The Therapeutic Goods Administration (TGA) warned telehealth companies against advertising prescription-only medicines directly to consumers. During GLP-1 medication shortages in 2023–2024, Eucalyptus partnered with compounding pharmacies to provide compounded semaglutide. This practice drew criticism from pharmaceutical manufacturers and regulators. The Australian federal government subsequently banned pharmacy compounding of GLP-1 drugs from October 2024. Media reports in The Sydney Morning Herald and The Australian questioned whether social media and influencer campaigns for Eucalyptus brands overstated treatment results. ABC's Media Watch raised concerns about whether television segments promoting the company's services blurred editorial and advertising boundaries. In response to regulatory concerns, Eucalyptus introduced phone-based GP consultations to replace asynchronous online forms. In June 2025, the TGA issued class-wide safety warnings for all GLP-1 and dual GIP/GLP-1 receptor agonists, including medications prescribed through Juniper, regarding aspiration risks during general anaesthesia. The warnings required updates to product information across all suppliers of these medications.
A major cause for the ineffectiveness of current chemotherapy treatments is multiple drug resistance which can arise from several mechanisms. Nanoparticles can provide a means to overcome MDR. In general, when using a targeting agent to deliver nanocarriers to cancer cells, it is imperative that the agent binds with high selectivity to molecules that are uniquely expressed on the cell surface. Hence NPs can be designed with proteins that specifically detect drug resistant cells with overexpressed transporter proteins on their surface. A pitfall of the commonly used nano-drug delivery systems is that free drugs that are released from the nanocarriers into the cytosol get exposed to the MDR transporters once again, and are exported. To solve this, 8 nm nanocrystalline silver particles were modified by the addition of trans-activating transcriptional activator (TAT), derived from the HIV-1 virus, which acts as a cell-penetrating peptide (CPP). Generally, AgNP effectiveness is limited due to the lack of efficient cellular uptake; however, CPP-modification has become one of the most efficient methods for improving intracellular delivery of nanoparticles. Once ingested, the export of the AgNP is prevented based on a size exclusion. The concept is simple: the nanoparticles are too large to be effluxed by the MDR transporters, because the efflux function is strictly subjected to the size of its substrates, which is generally limited to a range of 300-2000 Da. Thereby the nanoparticulates remain insusceptible to the efflux, providing a means to accumulate in high concentrations.
=== tib-tie === tibalosin (INN) tibeglisene (INN) tibenelast (INN) tibenzate (INN) tibezonium iodide (INN) tibolone (INN) tibric acid (INN) tibrofan (INN) ticabesone (INN) ticagrelor (USAN) ticarbodine (INN) ticarcillin (INN) ticarcillin/clavulanic acid TICE BCG (Organon Teknika Corp) ticlatone (INN) Ticlid ticlopidine (INN) ticolubant (INN) tideglusib (INN) tidembersat (INN) tidiacic (INN) tiemonium iodide (INN) tienilic acid (INN) tienocarbine (INN) tienopramine (INN) tienoxolol (INN)
In addition, the contributions of his foundation made possible a project introducing children to marine sciences, aboard the 90-foot research vessel the Robert G. Brownlee, built in 1998 and run by the Marine Science Institute (San Francisco Bay) of Redwood City, California. He died on February 27, 1991, of AIDS.
Sources: en.wikipedia.org
=== Introduction === Each country has its own vision on how the world originated, however each one agrees on the nature of the seasons, the day and the night. The seasons are given by the Agents through rituals of song and dance, while the day and the night are brought about by the arrows shot into the sky by the Archers of Dawn and Twilight. The safety of these figures is put at risk by individuals who hate the changing of the seasons and/or the alternation of the day and the night, known as "Insurgents". Because of this reason, Agents and Archers have a guard at their side, with whom they often tend to develop a strong bond of codependency. The story is set in contemporary times in the archipelago of Yamato, a land that rises in the middle of the ocean in the Far East, commonly called "Cherry Blossom of the East", due to the arrangement of its islands resembling the branches of a cherry blossom tree (N-to-S):
A separate co-op campaign is also available for up to four players, following a parallel plot where the players control a group of police officers that also get trapped in the nightmare world while investigating Simon. Additionally, there is also a co-op survival mode, where players fight several waves of enemies for a set period of time. Some days before Cry of Fear's anniversary, Valve released a Half-Life update for Linux compatibility, making changes in the folders and engine. This update made several Half-Life mods, including Cry of Fear, incompatible with the base game. Team Psykskallar decided that, since no more could be done for the mod itself, they would finish a standalone version. Confusion due to Valve regarding Cry of Fear's status as freeware caused the game to be delayed until April 25, 2013.
The Mesopotamians seem to have had little interest in the natural world as such, preferring to study how the gods had ordered the universe. Animal physiology was studied for divination, including especially the anatomy of the liver, seen as an important organ in haruspicy. Animal behavior too was studied for divinatory purposes. Most information about the training and domestication of animals was probably transmitted orally, but one text dealing with the training of horses has survived. The ancient Mesopotamians had no distinction between "rational science" and magic. When a person became ill, doctors prescribed both magical formulas to be recited and medicinal treatments. The earliest medical prescriptions appear in Sumerian during the Third Dynasty of Ur (c. 2112 – c. 2004 BCE). The most extensive Babylonian medical text, however, is the Diagnostic Handbook written by the ummânū, or chief scholar, Esagil-kin-apli of Borsippa, during the reign of the Babylonian king Adad-apla-iddina (1069 – 1046 BCE). In East Semitic cultures, the main medicinal authority was an exorcist-healer known as an āšipu. The profession was passed down from father to son and was held in high regard. Of less frequent recourse was the asu, a healer who treated physical symptoms using remedies composed of herbs, animal products, and minerals, as well as potions, enemas, and ointments or poultices. These physicians, who could be either male or female, also dressed wounds, set limbs, and performed simple surgeries.
=== Eliminating Sequences === Eliminate the sequences that are more than r% identical. There are two ways to eliminate the sequences. It can be done either by removing sequences from the block or just by finding similar sequences and replace them by new sequences which could represent the cluster. Elimination is done to remove protein sequences that are more similar than the specified threshold.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。