Thymalfasin is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-07-26. Numbers and descriptions here follow the published literature rather than marketing material.
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
| Property | Value | Notes |
|---|---|---|
| Amino acid length | 28 residues | Single chain with an acetylated N-terminus |
| Molecular mass | Approximately 3,108 Da | Small shifts occur with counter-ion and water content |
| Isoelectric point | Around 3.5 | Low value follows from the many acidic residues |
| Parent molecule | N-terminal region of prothymosin alpha | Free circulating form in humans is not firmly established |
| Common synonyms | Thymalfasin; T alpha 1 | Older literature also uses the full spelled-out form |
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
Similarities between the low-temperature state of undoped materials and the superconducting state that emerges upon doping, primarily the dx2−y2 orbital state of the Cu2+ ions, suggest that electron–electron interactions are more significant than electron–phonon interactions in cuprates – making the superconductivity unconventional. Recent work on the Fermi surface has shown that nesting occurs at four points in the antiferromagnetic Brillouin zone where spin waves exist and that the superconducting energy gap is larger at these points. The weak isotope effects observed for most cuprates contrast with conventional superconductors that are well described by BCS theory.
=== Fatty acids and insulin secretion === Fatty acids also affect insulin secretion. In type 2 diabetes, fatty acids are able to potentiate insulin release to compensate the increment need of insulin. It was found that the β-cells express free fatty acid receptors at their surface, through which fatty acids can impact the function of β-cells. Long-chain acyl-CoA and DAG are the metabolites resulting from the intracellular metabolism of fatty acids. Long-chain acyl-CoA has the ability to acylate proteins that are essential in the insulin granule fusion. On the other hand, DAG activates PKC that is involved in the insulin secretion.
=== Metabolism === The metabolism of progesterone is rapid and extensive, and it occurs mainly in the liver, though enzymes that metabolize progesterone are also expressed widely in the brain, skin, and various other extrahepatic tissues. Progesterone has an elimination half-life of only approximately five minutes in circulation. The metabolism of progesterone is complex, and it may form as many as 35 different unconjugated metabolites when it is ingested orally. Progesterone is highly susceptible to enzymatic reduction via reductases and hydroxysteroid dehydrogenases because of its double bond (between the C4 and C5 positions) and its two ketones (at the C3 and C20 positions). The major metabolic pathway of progesterone is reduction by 5α-reductase and 5β-reductase, into the dihydrogenated 5α-dihydroprogesterone and 5β-dihydroprogesterone, respectively. This is followed by the further reduction of these metabolites via 3α-hydroxysteroid dehydrogenase and 3β-hydroxysteroid dehydrogenase into the tetrahydrogenated allopregnanolone, pregnanolone, isopregnanolone, and epipregnanolone. Subsequently, 20α-hydroxysteroid dehydrogenase and 20β-hydroxysteroid dehydrogenase reduce these metabolites to form the corresponding hexahydrogenated pregnanediols (eight different isomers in total), which are then conjugated via glucuronidation and/or sulfation, released from the liver into circulation, and excreted by the kidneys into the urine.
=== Instability === Emulsion stability refers to the ability of an emulsion to resist change in its properties over time. There are four types of instability in emulsions: flocculation, coalescence, creaming/sedimentation, and Ostwald ripening. Flocculation occurs when there is an attractive force between the droplets, so they form flocs, like bunches of grapes. This process can be desired, if controlled in its extent, to tune physical properties of emulsions such as their flow behaviour. Coalescence occurs when droplets bump into each other and combine to form a larger droplet, so the average droplet size increases over time. Emulsions can also undergo creaming, where the droplets rise to the top of the emulsion under the influence of buoyancy, or under the influence of the centripetal force induced when a centrifuge is used. Creaming is a common phenomenon in dairy and non-dairy beverages (i.e. milk, coffee milk, almond milk, soy milk) and usually does not change the droplet size. Sedimentation is the opposite phenomenon of creaming and normally observed in water-in-oil emulsions. Sedimentation happens when the dispersed phase is denser than the continuous phase and the gravitational forces pull the denser globules towards the bottom of the emulsion. Similar to creaming, sedimentation follows Stokes' law. An appropriate surface active agent (or surfactant) can increase the kinetic stability of an emulsion so that the size of the droplets does not change significantly with time.
Sources: en.wikipedia.org
is the mass generation rate of the substance - assumed to be a constant, i.e. not a function of time (equal to zero for exogenous (foreign) substances/drugs) [mmol/min] or [mol/s] t is dialysis time or time since injection of the substance/drug [min] or [s] V is the volume of distribution or total body water [L] or [m3] K is the clearance [mL/min] or [m3/s] C is the concentration [mmol/L] or [mol/m3] (in the United States often [mg/mL]) From the above definitions it follows that
=== Explosives industry === At the 1936 meeting of the American Chemical Society, professor Edward Bartow of the University of Iowa presented a commercially viable means of extracting large amounts of inositol from the phytic acid naturally present in waste corn. As a possible use for the chemical, he suggested 'inositol nitrate' as a more stable alternative to nitroglycerin. Today, inositol nitrate is used to gelatinize nitrocellulose in many modern explosives and solid rocket propellants.
==== Electrolyte imbalances ==== Electrolytes like Na, K, Ca, and P can all cause mimicking symptoms when high or low. Most commonly, hypokalemia, or low K, is the culprit, since many common drugs decrease this electrolyte.
=== Interactions === Lorazepam is not usually fatal in overdose but may cause respiratory depression if taken in overdose with alcohol. The combination also causes greater enhancement of the disinhibitory and amnesic effects of both drugs, with potentially embarrassing or criminal consequences. Some experts advise that people should be warned against drinking alcohol while on lorazepam treatment, but such clear warnings are not universal. Greater adverse effects may also occur when lorazepam is used with other drugs, such as opioids or other hypnotics. Lorazepam may also interact with rifabutin. Valproate inhibits the metabolism of lorazepam, whereas carbamazepine, lamotrigine, phenobarbital, phenytoin, and rifampin increase its rate of metabolism. Some antidepressants, antiepileptic drugs such as phenobarbital, phenytoin, and carbamazepine, sedative antihistamines, opiates, antipsychotics, and alcohol, when taken with lorazepam may result in enhanced sedative effects.
Tartaric acid is an important component of some commonly used foods like unripe mangoes and tamarind. Natural fruits and vegetables also contain acids. Citric acid is present in oranges, lemon and other citrus fruits. Oxalic acid is present in tomatoes, spinach, and especially in carambola and rhubarb; rhubarb leaves and unripe carambolas are toxic because of high concentrations of oxalic acid. Ascorbic acid (Vitamin C) is an essential vitamin for the human body and is present in such foods as amla (Indian gooseberry), lemon, citrus fruits, and guava. Many acids can be found in various kinds of food as additives, as they alter their taste and serve as preservatives. Phosphoric acid, for example, is a component of cola drinks. Acetic acid is used in day-to-day life as vinegar. Citric acid is used as a preservative in sauces and pickles. Carbonic acid is one of the most common acid additives that are widely added in soft drinks. During the manufacturing process, CO2 is usually pressurized to dissolve in these drinks to generate carbonic acid. Carbonic acid is very unstable and tends to decompose into water and CO2 at room temperature and pressure. Therefore, when bottles or cans of these kinds of soft drinks are opened, the soft drinks fizz and effervesce as CO2 bubbles come out. Certain acids are used as drugs. Acetylsalicylic acid (Aspirin) is used as a pain killer and for bringing down fevers.
Sources: en.wikipedia.org
It is usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.
Prothymosin alpha is a much larger acidic protein, roughly 111 to 113 residues long, and the thymosin alpha-1 sequence matches its N-terminal region. The small peptide is therefore best understood as a fragment of that parent protein rather than a separate gene product.
Trials and clinical reports have examined chronic hepatitis B and C, use as a vaccine adjuvant, and supportive treatment in some immunodeficiency and oncology settings. Results vary by indication, and regulatory approval differs between countries.
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.