The short version of thymalfasin fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-28 and is reviewed periodically as new material appears.
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.
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.
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.
| 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 |
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.
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 synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
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.
=== Neurodegenerative diseases === Due to the ability of Ang to protect motoneurons (MNs), causal links between Ang mutations and amyotrophic lateral sclerosis (ALS) are likely. The angiogenic factors associated with Ang may protect the central nervous system and MNs directly. Experiments with wild type Ang found that it slows MN degeneration in mice that had developed ALS, providing evidence for further development of Ang protein therapy in ALS treatment. Angiogenin expression in Parkinson's disease is dramatically decreased in the presence of alpha-synuclein (α-syn) aggregations. Exogenous angiogenin applied to dopamine-producing cells leads to the phosphorylation of PKB/AKT and the activation of this complex inhibits cleavage of caspase 3 and apoptosis when cells are exposed to a Parkinson's-like inducing substance.
It instead provided economic and political aid, to avoid provoking the international community further, and to preserve the FR Yugoslavia as the republics of Serbia and Montenegro, rather than 'Greater Serbia.' In 1995, following Operation Storm, a military offensive by the Croatian Army, and NATO involvement in the Bosnian War, President Slobodan Milošević agreed to negotiate, as the Serbian position within Bosnia had become substantially worse. Under threat of economically crippling the Republika Srpska, he took over negotiating powers for all Serbian secessionist movements, as well as the FR Yugoslavia. The ensuing Dayton Agreements, signed between representatives from the Federal Republic of Yugoslavia, the Republic of Bosnia and Herzegovina and the Republic of Croatia, resulted in each state being recognised as sovereign states. It also provided recognition for Serbian institutions and a rotating presidency within Bosnia and Herzegovina, and the Serbian populated areas of the former Socialist Republic of Bosnia were absorbed into Bosnia and Herzegovina. Thus the Yugoslav Wars ended, and international sanctions on the FR Yugoslavia were lifted. Slobodan Milošević did not achieve his dreams of admitting the FR Yugoslavia to the United Nations as the successor state of the SFR Yugoslavia, as an 'outer wall' of international sanctions prohibited this.
=== Inducers === Many compounds commonly used in ferroptosis studies including erastin, RSL3 (RAS-selective lethal), ML162, and ML210 [from National Institutes of Health-Molecular Libraries Small Molecule Repository (NIH-MLSMR)] were initially identified in screens for compounds that can selectively kill cancerous mutant RAS cells. Initial studies characterized the mitochondrial VDAC2 and VDAC3 as the targets of erastin, though it was later found that the mechanistic target of erastin is the cystine/glutamate transporter system xc−. Erastin inhibits system xc−, lowering intracellular GSH levels. Consequently, the GSH-dependent GPX4 is unable to detoxify lipid hydroperoxide species, leading to ferroptotic cell death. Derivatives of erastin have been prepared to improve aqueous solubility, potency, and metabolic stability, with imidazole ketone erastin (IKE) being the most extensively studied. RSL3 and ML162 contain chloroacetamide moieties that can covalently react with nucleophilic residues. RSL3 and ML162 are able to bind to and inhibit GPX4 enzymatic activity or degrade GPX4 in lysate-based assays, though it has been found that RSL3 and ML162 do not inhibit purified GPX4 in vitro and target other selenoproteins such as thioredoxin reductase 1 (TXNRD1). However, other TXNRD1 inhibitors do not trigger ferroptosis, suggesting that TXNRD1 inhibition is not sufficient to trigger ferroptosis. The GPX4-inhibiting activity of RSL3 has also been suggested to be regulated by other factors such as 14-3-3ε or through broad targeting of the selenoproteome.
Oral progesterone (Prometrium) metabolizes into neurosteroids including allopregnanolone and pregnanolone which act as potent GABAA receptor positive allosteric modulators. As a result, oral progesterone can dose-dependently produce side effects including dizziness, drowsiness, sedation, somnolence, fatigue, anxiety reduction, euphoria, and cognitive impairment. For this reason, oral progesterone is often taken at night before bed. Oral progesterone taken before bed has been found to improve multiple sleep outcomes in clinical studies. Zuranolone is a synthetic analogue of allopregnanolone that likewise acts as a GABAA receptor positive allosteric modulator but is orally active. It is under development for the treatment of insomnia and is in phase 3 clinical trials for this indication as of September 2025.
In a study with 17 volunteers, blood and saliva samples were collected before and at 15, 30, 60 and 240 min after ingesting 1 g of paracetamol. Detection from stimulated saliva and plasma with PA-MS provided a reliable result that can aid in making timely treatment decisions. Moreover, participants' views of blood and saliva sampling procedures were assessed qualitatively, showing a preference for non-invasive sampling.
Sources: en.wikipedia.org
== Administration == Intravenous, usually 7.5 mg/kg every 8 hours (infections/life threatening VRSA); every 12 hours (skin infections). No renal dosing adjustments, hepatic dosing adjustments are not defined, consider reducing dose.
There have been a few instances of general population poisoning as the result of long-term exposure to cadmium in contaminated food and water. Research into an estrogen mimicry that may induce breast cancer is ongoing, as of 2012. In the decades leading up to World War II, mining operations contaminated the Jinzū River in Japan with cadmium and traces of other toxic metals. As a consequence, cadmium accumulated in the rice crops along the riverbanks downstream of the mines. Some members of the local agricultural communities consumed the contaminated rice and developed itai-itai disease and renal abnormalities, including proteinuria and glucosuria. The victims of this poisoning were almost exclusively post-menopausal women with low iron and low body stores of other minerals. Similar general population cadmium exposures in other parts of the world have not resulted in the same health problems because the populations maintained sufficient iron and other mineral levels. Thus, although cadmium is a major factor in the itai-itai disease in Japan, most researchers have concluded that it was one of several factors. Cadmium is one of ten substances banned by the European Union's Restriction of Hazardous Substances (RoHS) directive, which regulates hazardous substances in electrical and electronic equipment, but allows for certain exemptions and exclusions from the scope of the law. The International Agency for Research on Cancer has classified cadmium and cadmium compounds as carcinogenic to humans.
The chemical formula of cellulose is (C6H10O5)n where n is the degree of polymerization and represents the number of glucose groups. Plant-derived cellulose is usually found in a mixture with hemicellulose, lignin, pectin, and other substances, while bacterial cellulose is quite pure, has a much higher water content and higher tensile strength due to higher chain lengths. Cellulose consists of fibrils with crystalline and amorphous regions. These cellulose fibrils may be individualized by mechanical treatment of cellulose pulp, often assisted by chemical oxidation or enzymatic treatment, yielding semi-flexible cellulose nanofibrils generally 200 nm to 1 μm in length depending on the treatment intensity. Cellulose pulp may also be treated with strong acid to hydrolyze the amorphous fibril regions, thereby producing short rigid cellulose nanocrystals a few 100 nm in length. These nanocelluloses are of high technological interest due to their self-assembly into cholesteric liquid crystals, production of hydrogels or aerogels, use in nanocomposites with superior thermal and mechanical properties, and use as Pickering stabilizers for emulsions.
Some patients may believe they have determined their own allergic sensitivity from observation. A skin test is much better than patient observation for allergy detection. If a serious life-threatening anaphylactic reaction has brought a patient in for evaluation, some allergists may prefer to perform an initial blood test before conducting a skin prick test. Skin testing may also not be possible in patients with widespread skin disease or those who have taken antihistamine within the past several days.
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.