Thymosin Alpha-1 dosage in studies: doses, timing and reconstitution
The dose most often reported in these studies is 1.6 mg given subcutaneously twice a week, used in two chronic hepatitis B studies for six months. A melanoma trial compared 1.6, 3.2 and 6.4 mg alongside chemotherapy, and the largest sepsis trial gave thymosin α1 every 12 hours for seven days without stating the amount in its abstract. These are the doses used in those studies, reported for reference only.
What thymosin alpha 1 dosage have studies used? The figure that appears most often in the cited abstracts is 1.6 mg by subcutaneous injection twice a week. You et al. (2006) used it on its own for six months in HBeAg-positive chronic hepatitis B, and Saruc et al. (2003) used the same amount for 26 weeks alongside interferon alpha-2b in HBeAg-negative chronic hepatitis B.
Higher amounts have been tested in cancer research. Maio et al. (2010) randomised 488 patients with metastatic melanoma to arms containing 1.6, 3.2 or 6.4 mg of Tα1 with dacarbazine, with or without interferon alfa. The responses the authors highlighted were in the 3.2 mg arms. The abstract does not state how often each dose was given.
The sepsis trial differs in schedule. In the TESTS trial (Wu et al., 2025), thymosin α1 or placebo was given by subcutaneous injection every 12 hours for seven days, or until the patient left intensive care. The abstract does not state the amount per injection. In the HBV cirrhosis trial (Wu et al., 2018), Tα1 was added to entecavir for 52 weeks, and the abstract does not state the amount either.
Reviews in the records note that the best dose and schedule have not been settled. Pica et al. (2018) write that questions remain about the most effective dose and schedule, and Camerini et al. (2015) note that recent trials used higher doses than in the past. Neither review sets a figure.
For laboratory work, the site's calculator handles reconstitution arithmetic. As a neutral maths default it uses 1 mL of bacteriostatic water per 5 mg with a 2 mL minimum, so 2 mL for either the 5 mg or the 10 mg vial. This is arithmetic only, not a dose.
Doses used by each cited study
| Study | Model | Dose | Frequency | Duration |
|---|---|---|---|---|
| You J et al. 2006 | Human, randomised controlled trial, HBeAg-positive chronic hepatitis B (n=62) | 1.6 mg s.c. | Twice a week | Six months |
| Saruc M et al. 2003 | Human, non-randomised comparative study, HBeAg-negative chronic hepatitis B (n=52) | 1.6 mg s.c., with interferon alpha-2b | Twice a week | 26 weeks |
| Maio M et al. 2010 | Human, randomised trial, metastatic melanoma (n=488) | 1.6, 3.2 or 6.4 mg, with dacarbazine ± interferon alfa | Not stated in the abstract | Not stated in the abstract (primary end point at 12 months) |
| Wu J et al. 2025 | Human, randomised placebo-controlled phase 3 trial, sepsis (n=1106) | Not stated in the abstract | Every 12 hours, s.c. | Seven days |
| Wu X et al. 2018 | Human, randomised open-label trial, HBV-related compensated cirrhosis (n=690) | Not stated in the abstract, with entecavir | Not stated in the abstract | 52 weeks |
This table reports what each study used. It is not a recommendation or an instruction.
What these doses don't tell you
No study here is a dose-finding study in healthy people, and the melanoma trial is the only one that compared doses. Every dose above was used in patients with a specific disease, most often together with another drug, so none transfers to other settings.
Vial maths
| Vial | BAC water | Concentration | Per 0.01 mL (1 unit, U-100) |
|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 50 mcg |
| 5 mg | 2 mL | 2.5 mg/mL | 25 mcg |
| 5 mg | 3 mL | 1.667 mg/mL | 16.7 mcg |
| 10 mg | 1 mL | 10 mg/mL | 100 mcg |
| 10 mg | 2 mL | 5 mg/mL | 50 mcg |
| 10 mg | 3 mL | 3.333 mg/mL | 33.3 mcg |