The short version of nasal drops fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-15 and is reviewed periodically as new material appears.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
the reduction of growth hormone and insulin-like growth factor 1 (somatomedin C) in adults with acromegaly who have had inadequate response to or cannot be treated with surgical resection, pituitary irradiation, and bromocriptine mesylate at maximally tolerated doses severe diarrhea/flushing episodes associated with metastatic carcinoid tumors in adults profuse watery diarrhea associated with vasoactive intestinal peptide tumors (VIPomas) in adults
== Predictive genetic testing == Due to the high cost of immunotherapy and the reluctance of insurers to pre-authorize treatment, various genetic and molecular tests have been developed to predict therapeutic response. Three major biomarkers are currently FDA-approved and widely used in clinical practice: (1) programmed death-ligand 1 (PD-L1) expression, (2) microsatellite instability (MSI) or mismatch repair deficiency (dMMR), and (3) tumor mutational burden (TMB). PD-L1 expression, detected via immunohistochemistry, may indicate which tumors are more likely to respond to immune checkpoint inhibitors by revealing the presence of proteins that help cancer cells evade immune surveillance. However, its predictive value is limited by variability in expression across tumor types, locations, and testing platforms. MSI and dMMR, identified through molecular or immunohistochemical testing, indicate a deficiency in DNA repair mechanisms and are associated with high mutation rates that may increase tumor immunogenicity. These biomarkers have been approved to guide the use of checkpoint inhibitors in several cancer types. TMB, measured by next-generation sequencing, quantifies the total number of somatic mutations in a tumor genome. High TMB has been associated with improved responses to immunotherapy, although its clinical utility remains controversial and context-dependent. As of 2023, reliance on TMB as a selection criterion for immunotherapy was still debated in the scientific community.
According to author Mark Cartwright, "Inca roads covered over 40,000 km (25,000 miles), principally in two main highways running north to south across the Inca Empire, which eventually spread over ancient Peru, Ecuador, Chile and Bolivia." Several sources challenge Cartwright's claim in stating that the Inca roads covered either more or less area then he describes. This number is difficult to solidify since some of the pathways of the Inca still may remain unaccounted for, being that they may have been washed away or covered by natural forces. "Inca engineers were also undaunted by geographical difficulties and built roads across ravines, rivers, deserts, and mountain passes up to 5,000 meters high." Many of the constructed roads are not uniform in design. Most of the uncovered roads are about one to four meters wide. Although this is true, some roads, such as the highway in Huanuco Pampa province, can be much larger. As mentioned in the Pathway systems section, the Inca people mainly traveled on foot. Knowing this, the roads created were most likely built and paved for both humans and animals to walk and/or run along. Several roads were paved with stones or cobbles and some were "edged and protected with the use of small stone walls, stone markers, wooden or cane posts, or piles of stones." Drainage was something that was of particular interest and importance to the Inca people. Drains and culverts were built to ensure that rainwater would effectively run off of the road's surface.
Sources: en.wikipedia.org
=== Cancer === The IGF-1R is implicated in several cancers, including breast, prostate, and lung cancers. In some instances its anti-apoptotic properties allow cancerous cells to resist the cytotoxic properties of chemotherapeutic drugs or radiotherapy. In breast cancer, where EGFR inhibitors such as erlotinib are being used to inhibit the EGFR signaling pathway, IGF-1R confers resistance by forming one half of a heterodimer (see the description of EGFR signal transduction in the erlotinib page), allowing EGFR signaling to resume in the presence of a suitable inhibitor. This process is referred to as crosstalk between EGFR and IGF-1R. It is further implicated in breast cancer by increasing the metastatic potential of the original tumour by conferring the ability to promote vascularisation. Increased levels of the IGF-IR are expressed in the majority of primary and metastatic prostate cancer patient tumors. Evidence suggests that IGF-IR signaling is required for survival and growth when prostate cancer cells progress to androgen independence. In addition, when immortalized prostate cancer cells mimicking advanced disease are treated with the IGF-1R ligand, IGF-1, the cells become more motile. Members of the IGF receptor family and their ligands also seem to be involved in the carcinogenesis of mammary tumors of dogs. IGF1R is amplified in several cancer types based on analysis of TCGA data, and gene amplification could be one mechanism for overexpression of IGF1R in cancer.
=== Levels === Prior to puberty in humans, DHEA and DHEA-S levels elevate upon differentiation of the zona reticularis of the adrenal cortex. Peak levels of DHEA and DHEA-S are observed around age 20, which is followed by an age-dependent decline throughout life eventually back to prepubertal concentrations. Plasma levels of DHEA in adult men are 10 to 25 nM, in premenopausal women are 5 to 30 nM, and in postmenopausal women are 2 to 20 nM. Conversely, DHEA-S levels are an order of magnitude higher at 1–10 μM. Levels of DHEA and DHEA-S decline to the lower nanomolar and micromolar ranges in men and women aged 60 to 80 years. DHEA levels are as follows:
The Litton detector was developed for sampling the light energy distribution in the rear focal-plane of a spherical lens for sampling geometric relationships and the spectral density distribution of objects recorded on film transparencies. The application of the Litton detector by Salzman et al. provided measurement at 32 small scattering angles between 0° and 30°, and averaging over a broad range of azimuthal angles as the most important angles are the forward angles for static light scattering. By 1980, Bartholi et al. had developed a new approach to measuring the scattering at discrete scattering angles by using an elliptical reflector to permit measurement at 30 polar angles over the range 2.5° ≤ θ ≤ 177.5° with a resolution of 2.1°. The commercialization of multiangle systems began in 1977 when Science Spectrum, Inc. patented a flow-through capillary system for a customized bioassay system developed for the USFDA. The first commercial MALS instrument incorporating 8 discrete detectors was delivered to S.C. Johnson and Son, by Wyatt Technology Company, in 1983, followed in 1984 with the sale of the first 15 detector flow instrument (Dawn-F) to AMOCO. By 1988, a three-dimensional configuration was introduced specifically to measure the scattering properties of single aerosol particles. At about the same time, the underwater device was built to measure the scattered light properties of single phytoplankton. Signals were collected by optical fibers and transmitted to individual photomultipliers.
Sources: en.wikipedia.org
=== Notable incidents of use === DJ Screw, who popularized the codeine-based drink, died of a codeine–promethazine, Valium, and PCP overdose on November 16, 2000, several months after the video of Three 6 Mafia's single debuted. Big Moe, a DJ Screw protégé whose albums City of Syrup and Purple World were based on the drink and who has been described as having "rapped obsessively about the drug", died at age 33 on October 14, 2007, after suffering a heart attack one week earlier that left him in a coma. There was speculation that lean may have contributed to his death. Pimp C, a widely influential rapper from Port Arthur, Texas, and member of the rap duo UGK, was found dead on December 4, 2007, at the Mondrian Hotel in West Hollywood, California. The Los Angeles County Coroner's Office reported that the rapper's death was "due to promethazine-codeine effects and other unestablished factors." Ed Winter, assistant chief of the Coroner's Office, said the levels of the medication were elevated, but not enough to deem the death an overdose. However, Pimp C had a history of sleep apnea, a condition that causes one to stop breathing for short periods during sleep. A spokesman for the coroner's office said that the combination of sleep apnea and cough medication probably suppressed Pimp C's breathing long enough to bring on his death. Fredo Santana, an American rapper who frequently made references to the drink in his music, died of a seizure on January 19, 2018.
Duterte has been linked by human rights groups such as Amnesty International and Human Rights Watch to extrajudicial killings of over 1,400 alleged criminals and street children by vigilante death squads. In the April 2009 UN General Assembly of the Human Rights Council, the UN report (Eleventh Session Agenda item 3, par 21) said, "The Mayor of Davao City has done nothing to prevent these killings, and his public comments suggest that he is, in fact, supportive." Duterte emphasized that the concept of human rights for criminals is Western and should not apply to the Philippines; he further challenged human rights officials to file a case against him if they could provide evidence of his links with vigilante groups.
=== Skinny Revolution === Pickston founded Skinny Revolution to help people to lose weight after she gained 7 stone in 14 months, partly whilst pregnant, using a Wegovy (semaglutide) injection, which is a 2.4 mg injectable prescription medicine used as an appetite suppressant.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.