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    Immune & InflammationHuman trials (1980s)

    Thymulin Dosage Guide: Protocols, Calculator & Safety

    Everything you need to know about Thymulin dosing: protocols, safety, and where to buy.

    Half-Life

    No published human value. In rats, intravenously injected FTS was cleared from blood with a half-life of 2 to 3 minutes (PMID: 8082705). In a single sheep injected with thymulin, serum thymulin fell with a half-life of 10.3 plus or minus 0.6 minutes (PMID: 8040352). Normal human and mouse serum also contains a larger molecule, the size of albumin or prealbumin, that binds FTS and carries it, which the discovery group proposed accounts for FTS-like activity in high molecular weight serum fractions (PMID: 7189463).

    Administration Routes

    IntravenousSubcutaneousIntraperitonealIntracerebroventricular

    Quick Reconstitution Calculator

    Calculate syringe units instantly

    Syringe Draw

    10.0 units

    2500 mcg/ml · 0.100 ml draw

    Full Tool

    For laboratory research use only. This tool performs reconstitution math (concentration and syringe-unit conversion) and is not dosing guidance for humans or animals.

    Dosing data for Thymulin is being researched. Check the compound page for the latest information.

    Side Effects & Safety

    Human safety reporting for thymulin is thin and old, and it comes from four small studies. **Randomized trials.** The two double-blind rheumatoid arthritis trials that compared 1, 5 and 10 mg a day against placebo reported that the effect at the 5 mg dose came with minimal adverse effects (PMID: 3310925). The multiple sclerosis trial, which gave 40 matched patients subcutaneous nonathymulin or placebo for six months, recorded no significant side effects and also no benefit (PMID: 2618585). **Case series.** Three children with IgA and IgE deficiency and T-cell defects were given synthetic FTS intravenously; the report describes reduced frequency and severity of infection and improved immunological measures and lists no adverse events (PMID: 6124716). None of these studies is large enough to describe uncommon harms. **Animal findings that cut against a simple anti-inflammatory picture.** The direction of effect in rodents depends on dose. Low nanogram doses of thymulin injected into the paw or the peritoneum of intact rats produced hyperalgesia with a rise in pro-inflammatory mediators, while higher microgram doses reduced inflammatory pain (PMID: 17192563; PMID: 9876233). Long-term FTS treatment of lupus-prone mouse strains prevented or reversed autoimmune sialoadenitis but left anti-DNA antibody production unchanged in one strain and accelerated it in another, and the authors urged caution about extending the approach to human lupus (PMID: 7192987). Autoimmune and diabetic mouse strains spontaneously make autoantibodies against thymulin (PMID: 6539799). **Reviews.** A 2010 review of thymulin in lung disease states that the peptide has no toxicity even at high doses in the animal models reviewed and that adenovirally expressed thymulin reduced the immune response against viral proteins (PMID: 20055713). That is a reviewer's summary of animal work, not a human safety finding. No long-term human safety data exist, no paediatric or pregnancy data exist beyond the three-child case series above, and nothing has been published on topical application to human skin or scalp.

    Contraindications

    No product labelling exists, so there is no official contraindication list. The cautions in the literature are mechanism-based. Thymulin is biologically active only when it carries zinc, so its activity tracks zinc status: human volunteers made mildly zinc deficient by diet lost serum thymulin activity and regained it with zinc, and adding zinc sulphate to plasma from older adults and from people with Down syndrome raised measured FTS to the levels seen in young healthy people (PMID: 6957870; PMID: 3262625; PMID: 6143966). Any reading of a thymulin measurement or a thymulin effect without zinc status alongside it is hard to interpret. In autoimmunity the animal data point both ways. Repeated FTS treatment of NZB and NZB-crossed-with-NZW mice prevented or cured autoimmune sialoadenitis while leaving anti-DNA antibody production unaffected in one strain and accelerating it in another; the authors wrote that caution is urged before applying the approach to human lupus (PMID: 7192987). In vitro, thymulin shifted the OKT4 to OKT8 ratio toward normal in lymphocytes from eight of nine rheumatoid arthritis patients but did not change the ratio in four patients with systemic lupus erythematosus (PMID: 6332789). Dose direction matters in rodents: low nanogram doses produced hyperalgesia and raised pro-inflammatory mediators in intact rats, the opposite of the effect reported at microgram doses (PMID: 17192563). Circulating thymulin moves with thyroid hormone, growth hormone and corticotrophin in humans and rats (PMID: 3944232; PMID: 2289783; PMID: 21554609), so endocrine disease is a reason to interpret thymulin levels carefully rather than a reason to expect a particular response.

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    Frequently Asked Questions

    What is the recommended Thymulin dosage?

    Dosage for Thymulin varies by protocol. Consult a qualified healthcare provider.

    How often should I take Thymulin?

    Administration frequency depends on the specific protocol. Consult current research literature.

    Does Thymulin need to be cycled?

    Cycling requirements depend on the protocol. Follow established research guidelines.

    What are Thymulin side effects?

    Human safety reporting for thymulin is thin and old, and it comes from four small studies. **Randomized trials.** The two double-blind rheumatoid arthritis trials that compared 1, 5 and 10 mg a day against placebo reported that the effect at the 5 mg dose came with minimal adverse effects (PMID: 3310925). The multiple sclerosis trial, which gave 40 matched patients subcutaneous nonathymulin or placebo for six months, recorded no significant side effects and also no benefit (PMID: 2618585). **Case series.** Three children with IgA and IgE deficiency and T-cell defects were given synthetic FTS intravenously; the report describes reduced frequency and severity of infection and improved immunological measures and lists no adverse events (PMID: 6124716). None of these studies is large enough to describe uncommon harms. **Animal findings that cut against a simple anti-inflammatory picture.** The direction of effect in rodents depends on dose. Low nanogram doses of thymulin injected into the paw or the peritoneum of intact rats produced hyperalgesia with a rise in pro-inflammatory mediators, while higher microgram doses reduced inflammatory pain (PMID: 17192563; PMID: 9876233). Long-term FTS treatment of lupus-prone mouse strains prevented or reversed autoimmune sialoadenitis but left anti-DNA antibody production unchanged in one strain and accelerated it in another, and the authors urged caution about extending the approach to human lupus (PMID: 7192987). Autoimmune and diabetic mouse strains spontaneously make autoantibodies against thymulin (PMID: 6539799). **Reviews.** A 2010 review of thymulin in lung disease states that the peptide has no toxicity even at high doses in the animal models reviewed and that adenovirally expressed thymulin reduced the immune response against viral proteins (PMID: 20055713). That is a reviewer's summary of animal work, not a human safety finding. No long-term human safety data exist, no paediatric or pregnancy data exist beyond the three-child case series above, and nothing has been published on topical application to human skin or scalp.

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