Lyophilized powder 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.
Last reviewed on 2026-01-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
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.
High entry barriers because of demanding technology: the construction of a large-scale plant for the production of biopharmaceuticals by cell culture fermentation costs around $500 million and takes four to six years. As the specifications of the plant and process types for biopharmaceuticals differ substantially from traditional chemical synthesis, they cannot be produced in conventional multipurpose fine chemical plants. High financial exposure, due to high capital intensity (as massive investments are needed at a time when chances of success are still very low) and risk of batch failures (contamination). Unlike the biopharmaceutical start-ups, the emerging big biopharmaceutical companies are adopting the same opportunistic outsourcing policy as larger pharmaceutical companies. Thus, Amgen, Biogen Idec, Eli Lilly, Johnson & Johnson (J&J), Medimmune, Novartis, Roche-Genentech and Pfizer are investing heavily in in-house manufacturing capacity. With three plants in the US, two in Japan and one each in Germany and Switzerland, Roche has the largest production capacity. New developments in expression systems for mammalian and plant cell technology could reduce capacity requirements substantially: the titer in large-scale mammalian production, 2–3 grams/liter, is expected to double to 5–7 by 2015 go up to 10 by 2020. Furthermore, the widespread application of "single-use disposable bioprocessing technology" advantageously substitutes for stainless steel production trains, at least for short production campaigns.
As such, whereas other TCAs can be combined with monoamine oxidase inhibitors (with caution due to the risk of hypertensive crisis from NET inhibition; sometimes done in treatment-resistant depressives), clomipramine cannot be due to the risk of serotonin syndrome and death. Unlike the case of its serotonin receptor antagonism, orthostatic hypotension is a common side effect of clomipramine, suggesting that its blockade of the α1-adrenergic receptor is strong enough to overcome the stimulatory effects on the α1-adrenergic receptor of its NET inhibition.
== History == ACAM2000 is a vaccine developed by Acambis, which was acquired by Sanofi Pasteur in 2008, before selling the smallpox vaccine to Emergent Biosolutions in 2017. Six strains of vaccinia were isolated from 3,000 doses of Dryvax and found to exhibit significant variation in virulence. The strain with the most similar virulence to the overall Dryvax mixture was selected and grown in MRC-5 cells to make the ACAM1000 vaccine. After a successful Phase I trial of ACAM1000, the virus was passaged three times in Vero cells to develop ACAM2000, which entered mass production at Baxter. The United States ordered over 200 million doses of ACAM2000 in 1999–2001 for its stockpile, and production is ongoing to replace expired vaccine. Emergent Biosolutions developed ACAM2000 under a contract with the US Centers for Disease Control and Prevention (CDC). The US Food and Drug Administration (FDA) approved ACAM2000 in August 2007. By February 2008, it replaced Dryvax for all smallpox vaccinations. As of 2010, there were over 200 million doses manufactured for the US Strategic National Stockpile. According to the US FDA, "The approval and availability of this second-generation smallpox vaccine in the Strategic National Stockpile (SNS) enhances the emergency preparedness of the United States against the use of smallpox as a dangerous biological weapon." In August 2024, ACAM2000 was approved for mpox prevention in the United States.
Bacon – some forms of bacon are dried, such as freeze-dried bacon. Bakkwa – a Chinese salty-sweet dried meat product similar to jerky. Bakkwa is made with a meat preservation and preparation technique originating from China. Bayonne ham – an air dried salted ham that takes its name from the ancient port city of Bayonne in the far South West of France, a city located in both the cultural regions of Basque Country and Gascony. Jambon de Bayonne has PGI status. It is a slightly sweet, delicately flavored meat with little salt to the taste. Biltong – a variety of cured meat that originated in Southern Africa, various types of meat are used to produce it, ranging from beef and game meats to fillets of ostrich from commercial farms. It is typically made from raw fillets of meat. Black Forest ham – a variety of dry-cured smoked ham, a pork product, produced in the Black Forest region of Germany. Ham is the thigh and rump from the haunch of a pig or boar. It is the best-selling smoked ham in Europe. Borts – a Mongolian air-dried meat with preparation involving cutting the meat into long strips which are hung in the shade. Bresaola – air-dried, salted beef that has been aged two or three months until it becomes hard and turns a dark red, almost purple color. It is made from top (inside) round, and is lean and tender, with a sweet, musty smell. It originated in Valtellina, a valley in the Alps of northern Italy's Lombardy region. Brési – beef which has been salted, dried and smoked over a period of three months, which is made in the Department of Doubs.
Battle of Hébuterne — A second German counterattack was also repulsed by the French. British tanker Desabla was torpedoed, shelled, and sunk in the North Sea by German submarine SM U-17. Georgia Governor John M. Slaton opened hearings on the Leo Frank case in which he accepted both trial and new evidence, which included over 10,000 pages of documents and visits to the crime scene. When the hearing wrapped, Stanton produced a 29-page report that concluded there was sufficient new evidence not available at the original trial that cast doubt on Frank's guilt and ordered the death sentence to be commuted to life imprisonment. The University of Georgia established a school for journalism, now known as the Henry W. Grady College of Journalism and Mass Communication. Tennis pro Molla Mallory won the women's singles at the U.S. National Championships, beating Hazel Hotchkiss Wightman 4–6, 6–2, 6–0. American writer Alice Duer Miller released her satirical poetry collection Are Women People? in hardcover by the George H. Dorman company, following a weekly run through the newspaper New-York Tribune. Born: David Rockefeller, American banker, chairman of the Chase Manhattan Bank from 1969 to 1981, member of the Rockefeller family; in New York City, United States (d. 2017) Priscilla Lane, American actress and singer, best known for lead roles in The Roaring Twenties, Saboteur, and Arsenic and Old Lace; as Priscilla Mullican, in Indianola, Iowa, United States (d. 1995) Barbara Leonard Reynolds, American activist, co-owner with husband Earle L.
Sources: en.wikipedia.org
Victoria confronts her father, General Byng, about the town's problems, and he instructs her to start taking her Joy again and check in on Dr. Verloc at Haworth Labs, where he is working on a permanent replacement for Joy. However, her progress is halted by a strike by the lab workers, who demand that Sally be reinstated to her position in the lab. After helping suppress the strike, Victoria confronts Dr. Verloc. Realizing that Dr. Verloc has no permanent solution and is willing to let the populace die off to "sustainable" levels, Victoria resolves to cut off the town's Joy supply to wean them off the drug. In order to achieve these, she destroys both the pill allocator and water treatment plant responsible for distributing Joy throughout the town. She is arrested and thrown in jail, where she remembers how her mother was imprisoned in India for supporting Indian independence from Britain. General Byng helps her escape, and informs her about his safe house where he has stockpiled supplies and an escape boat. Shocked at her father's cowardice and willingness to abandon the town to its fate, Victoria rejects his offer and resolves to save the town. In order to permanently stop all Joy production, she demolishes Haworth Labs, narrowly escaping its destruction. The combination of the destruction of the Joy supply and the broadcast of Uncle Jack's final recording sends Wellington Wells into complete anarchy as the enraged citizens slaughter each other.
While filming the picture, Kidder stated she "fell in love with Pryor in two seconds flat," and the two carried on a relationship during the production. In 1982, she appeared in a stage performance of Bus Stop, playing Cherie opposite Tim Matheson as Bo, which was broadcast on HBO. Kidder's role in 1983's Superman III was notably small, consisting of 12 lines and less than five minutes of footage. This was reportedly a result of her previous objections to Richard Lester replacing Richard Donner as director for Superman II, though the producers have denied this in DVD commentaries. The same year Superman III was released, Kidder also starred as a court stenographer-cum-private eye named Mickey Raymond in the comedy Trenchcoat (1983). Critic Roger Ebert disliked the film, deeming it "one of the most tired, predictable, uninteresting movies in a long time." Also in 1983, Kidder produced and starred as Eliza Doolittle in a version of Pygmalion with Peter O'Toole for Showtime. In 1984, Kidder produced and starred in the French-Canadian period television film Louisiana as a plantation owner in the American South, who returns from Paris to find her estate and holdings have been lost. Also, she reunited with her former Nichols co-star, James Garner, in the Hollywood crime drama The Glitter Dome, and appeared in the drama Little Treasure for Columbia Tri-Star, with co-stars Ted Danson and Burt Lancaster, in which she played a distraught stripper looking for her bank robber-father's buried fortune.
== Medical uses == Treatment of unstable angina (UA) and non-ST elevated myocardial infarction (NSTEMI), administered concurrently with aspirin DVT and pulmonary embolism prophylaxis in bed-ridden patients DVT prophylaxis in knee replacement surgery DVT prophylaxis in hip replacement surgery DVT prophylaxis in abdominal surgery Treatment of DVT with or without pulmonary embolism Treatment of DVT inpatient, with ST-segment elevation myocardial infarction (STEMI) Bridging treatment for those with INR below therapeutic range
Yeung Sik Yuen in accordance with Sub-Commission on the Promotion and Protection of Human Rights resolution 2001/36. He argues that the use of DU in weapons, along with the other weapons listed by the Sub‑Commission, may breach one or more of the following treaties: the Universal Declaration of Human Rights, the Charter of the United Nations, the Genocide Convention, the United Nations Convention Against Torture, the Geneva Conventions including Protocol I, the Convention on Conventional Weapons of 1980, and the Chemical Weapons Convention. Yeung Sik Yuen writes in Paragraph 133 under the title "Legal compliance of weapons containing DU as a new weapon":
=== Pharmacokinetics === When taken by mouth, canagliflozin reaches highest blood plasma concentrations after one to two hours and has an absolute bioavailability of 65%, independently of food intake. When in the bloodstream, 99% of the substance are bound to plasma proteins, mainly albumin. It is metabolized mainly by O-glucuronidation via the enzymes UGT1A9 and UGT2B4, and by hydroxylation to a lesser extent. The terminal half life is 10.6 hours for a 100 mg dose and 13.1 hours for a 300 mg dose, with 43% being excreted in the faeces (mostly in unchanged form) and 33% in the urine (mostly as glucuronide).
Sources: en.wikipedia.org
=== Rett Syndrome === Missense mutations in the MeCP2 protein can cause Rett syndrome, otherwise known as the RTT phenotype. This phenotype primarily effects females, as males do not live with this mutation past infancy. T158M, R306C and R133C are the most common missense mutations causing RTT. T158M is a mutation of an adenine being substituted for a guanine causing the threonine at amino acid position 158 being substituted with a methionine. R133C is a mutation of a cytosine at base position 417 in the gene encoding the MeCP2 protein being substituted for a thymine, causing an amino acid substitution at position 133 in the protein of arginine with cysteine.
==== Electrofocusing ==== Electrofocusing is a specialized technique that separates proteins based on their isoelectric points in a pH gradient. As an electric field is applied, proteins migrate until they reach the point where their net charge is zero, effectively focusing them into narrow bands. This method provides high resolution and is often used in combination with other techniques for comprehensive protein analysis.
In preparation for the 1998 finals series, and despite losing six of their last eight to the Roos, legendary Essendon coach Kevin Sheedy publicly labelled North executives Greg Miller and Mark Dawson soft in response to comments from commentators that his Essendon team was soft. The Kangaroos beat Essendon in the much-hyped encounter that followed (a Qualifying Final), and North fans pelted Sheedy with marshmallows as he left the ground, although Sheedy was seemingly unfazed by the incident, encouraging a "Marshmallow Game" the next year and relishing in the fact that Sheedy's ulterior motive was to build up the game and draw a large crowd, which proved to be correct, drawing in 71,154 people to attend the game. In 2000, the Bombers thrashed North by 125 points in the 1st Qualifying Final. The biggest VFL/AFL comeback of all time occurred between the two teams when Essendon managed to come back from a 69-point deficit to win by 12 points in 2001. A meeting of the two rivals at the MCG in the 2014 AFL finals series in the 2nd Elimination Final resulted in North winning by 12 points. West Coast – A three-decade rivalry between the Essendon Bombers and the West Coast Eagles kicked off when Essendon coach Kevin Sheedy tied the windsock down on the School End outer terrace so the opposition would not know which way the wind was blowing. Sheedy later said of the incident three decades later, in jest, that it was because the brand sponsor had neglected to pay their account. When West Coast won the toss and kicked against the breeze, it looked as if Sheedy's plan had worked.
=== Redox === Hydroquinone can be reversibly oxidised under mild conditions to give benzoquinone. Naturally occurring hydroquinone derivatives, such as coenzyme Q, exhibit similar reactivity, wherein one hydroxyl group is exchanged for an amino group. Given the conditional reversibility and relative ubiquity of reagents, oxidation reactions of hydroquinones and hydroquinone derivatives are of significant commercial use, often used at an industrial scale. When colorless hydroquinone and benzoquinone—bright yellow in solid form—are cocrystallized at a 1:1 ratio, a dark-green crystalline charge-transfer complex (melting point 171 °C), known as quinhydrone (C6H6O2·C6H4O2), is formed. This complex dissolves in hot water, dissociating both quinone molecules in solution.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.