Thymosin Alpha-1 Dosage Chart and Calculator: Immune Support Protocol (2026)

Thymosin alpha-1 (TA1) is a 28-amino-acid peptide first isolated from the thymus, the gland where T cells learn their job. Few research peptides have a drug behind them; this one does. Made synthetically as thymalfasin and sold under the name Zadaxin, it is approved in more than 30 countries, and its label dose of 1.6mg is the number almost every protocol starts from.

Simms Research stocks Thymosin Alpha-1 in a single size, 10mg, priced at $72. All the draws in this guide are for that vial dissolved in 2mL of bacteriostatic water, where one unit on an insulin syringe (U-100) holds 50mcg.

Thymosin alpha-1 dosage calculator

Pick the water and the dose, and the calculator gives the units to draw on a U-100 insulin syringe. It opens on a 10mg vial with 2mL and a 1.6mg dose: 32 units.

Thymosin alpha-1 dosage chart

Most protocols put 1 to 1.6mg of thymosin alpha-1 in each injection, and 1.6mg, 32 units from the 2mL mix, is the figure nearly all of them are built on:

The 1.6mg row is the one with clinical history behind it. The 1mg and 1.5mg rows come from daily protocols, which spread a larger weekly amount over more injections. Draws of 30 and 32 units are easiest to measure on a 0.5mL syringe, which marks every single unit.

Thymosin alpha-1 10mg reconstitution

2mL. At 5mg per mL the standard 1.6mg sits at 32 units, 1mg at 20, and the vial’s full contents at 200.

Point the stream at the inside wall so it trickles down to the powder, then tilt and turn the vial slowly until nothing solid is left. TA1 dissolves readily and ends up as clear as plain water. Date the vial, store it cold and finish it inside four weeks. The same routine, step by step, is in how to reconstitute peptides.

Simms Research’s Research Water comes in 10mL for $20, enough for five TA1 vials at 2mL each. Why bacteriostatic water, and not plain sterile water, suits a vial opened over several weeks is in the bac water guide.

For anything off the chart, such as the 5mg vials many shops sell or a different volume of water, the peptide calculator works out the draw. With 2mL in a 5mg vial, for instance, 1.6mg is 64 units, double the 10mg figure.

Thymosin alpha-1 dosage protocol: the 1.6mg standard

1.6mg twice a week, injected under the skin (Chien, Hepatology, 1998). That is the Zadaxin label dose for chronic hepatitis B, given for 6 to 12 months, and it equals 900mcg per square metre of body surface. Adults under 40kg get 40mcg per kg instead; above that the dose is flat, with nothing added for weight or changed for sex.

The same 1.6mg carries through the rest of the clinical record: the hepatitis C trials paired it with interferon for 6 to 12 months, and the sepsis and COVID-19 studies gave it daily. From the 10mg vial it is 32 units, on two days three or four days apart; Monday and Thursday is the usual pair.

Thymosin alpha-1 daily vs twice weekly

Twice weekly is the schedule with the trial record; daily is the one most community protocols run. On a daily protocol the draw is 1 to 1.6mg a day, often five days on and two off; on the standard it is 3.2mg a week in two injections.

Neither rhythm keeps TA1 in the blood between draws. Per the label, it peaks about two hours after an injection, has a half-life of about two hours and is back to baseline within 24, with no build-up from repeated doses. What the hepatitis trials measured came slowly: viral markers falling over months of twice-weekly dosing. The daily camp reasons that a peptide gone within a day is better given every day. The two have never been tested against each other, and the weekly totals differ more than the draws do:

Thymosin alpha-1 dosage when sick

Short and daily. When studies used TA1 during an acute infection, they gave the standard 1.6mg every day, or twice a day, for about a week, instead of twice a week for months.

In the ETASS trial (Critical Care, 2013), 361 intensive-care patients with severe sepsis received 1.6mg twice a day for five days, then once a day for two. Deaths within 28 days were 26.0% against 35.0% in the control group, a gap that fell just short of statistical significance (Wu, Critical Care, 2013). The larger TESTS trial (BMJ, 2025) gave 1,106 adults with sepsis 1.6mg every 12 hours for seven days and found no difference: 23.4% against 24.1% on placebo.

COVID-19 produced the same split. A Wuhan study of 76 severe cases gave 1.6mg once a day for at least seven days and recorded 11.1% mortality against 30.0% without it; a 19-hospital study of 771 critically ill patients found 51.0% against 52.9% once the groups were matched, no difference.

Protocols in circulation follow the short-course shape: 1.5 to 1.6mg, 30 to 32 units, every day for one to two weeks, then back to twice weekly or a stop. The long courses belong to chronic conditions, such as the hepatitis trials’ six to twelve months.

Thymosin alpha-1: morning or night

Either works. The label and the trials fix the days, not the hour, and a dose is cleared within a day whenever it goes in. Most protocols settle on the morning and keep that time from one injection to the next; on the twice-weekly schedule the spacing of three to four days matters more than the clock.

Thymosin alpha-1 cycle length

The trials didn’t cycle it. Hepatitis courses ran twice a week for six to twelve months without a break, and the label reports no accumulation over that time.

Cycles come from the community protocols. The five-on, two-off daily routine usually runs in blocks of about eight weeks, followed by a similar break, and twice-weekly blocks of 4 to 12 weeks are common. Short courses of one to two weeks need no cycle at all: they simply end. The break between blocks is habit, not evidence: no trial has tested one cycle length against another.

Thymosin alpha-1 10mg vial: how long it lasts

Three weeks on the standard twice-weekly schedule, and about a week on the daily ones:

Each of these runs the vial dry long before its 28-day fridge limit. A one-week short course at 1.6mg a day takes seven draws, so its last day comes from a second vial. Six 32-unit draws use 192 of the vial’s 200 units, leaving 8 behind.

Thymosin alpha-1 side effects

Most runs show nothing beyond the injection itself. The thymalfasin label draws on more than 2,000 people of all ages treated for many different diseases, and puts drug-related adverse events below 1% for every use. What does occur is mild, mostly brief discomfort where the injection went in; redness, short-lived muscle wasting, joint pain with swollen hands, and rash appear only as rare reports.

The largest placebo-controlled trial puts numbers on it. In TESTS, 66.4% of the seriously ill sepsis patients given TA1 had at least one adverse event, against 67.6% on placebo, and serious events ran 26.8% against 29.3%: no more often with the peptide than without it (Wu, BMJ, 2025).

Thymosin alpha-1 batch test results

Every vial tested held more than its 10mg label. The latest batch went to an independent ISO-certified lab, which reported on July 16, 2026 after running three vials one by one:

The lab read purity by RP-HPLC and confirmed the peptide’s identity by LC-MS. Endotoxins passed, the four heavy metals it screens for (arsenic, cadmium, lead, mercury) were all negative, and the sterility culture showed no growth. February 2026’s batch, a single vial on HPLC-UV, measured 11.64mg at 99.34% and passed endotoxins as well.

In practice the overfill makes every draw slightly stronger than the chart: 11.81mg in 2mL puts about 1.9mg in 32 units. Typing 11.81mg into the calculator as the vial size brings 1.6mg down to 27 units, and a vial then gives seven standard draws. The COA reading guide explains what each field means, and the Thymosin Alpha-1 lab results page holds both certificates in full.

Frequently asked questions

What is thymosin alpha-1 used for?

As Zadaxin it is approved in over 30 countries for hepatitis B and C, in certain cancers and as an immune enhancer, depending on the country. Research studies its effect on T-cell maturation and on the immune response to infection and vaccines.

How many units is 1.6mg of thymosin alpha-1?

32, with the 10mg vial mixed in 2mL. At that strength 1.5mg is 30 units and 1mg is 20.

Can thymosin alpha-1 be taken daily?

Yes. Protocols that run it daily use 1 to 1.6mg, and the sepsis and COVID-19 studies gave 1.6mg once or twice a day for about a week. The long clinical courses stayed at twice weekly.

How long does thymosin alpha-1 take to work?

Weeks to months in the clinical work. In hepatitis B the response built slowly, and the label notes responses appearing 12 months or more after a course had ended. The sepsis trials read their result at 28 days.

Is thymosin alpha-1 the same as TB-500?

No. Both names trace back to thymus extracts, but TB-500 is a seven-amino-acid stretch of thymosin beta-4, a separate 43-amino-acid protein studied for tissue repair. Thymosin alpha-1 is the 28-amino-acid immune peptide, with its own dose.

Does thymosin alpha-1 work orally or as a nasal spray?

The clinical work is all injection under the skin, and the label says it is not for the vein. Capsule and spray versions exist; the milligrams here apply to injected TA1 only.

Does thymosin alpha-1 need to be refrigerated?

Yes, in both forms. Mixed TA1 lives in the fridge for up to 28 days. The powder is stored cold as well, yet copes with a few weeks at room temperature, so it travels without ice packs. More detail is in the peptide refrigeration guide.

Can thymosin alpha-1 be stacked with KPV or BPC-157?

Yes. Each goes in its own vial at its own amount: KPV at 200 to 500mcg a day (see the KPV dosage chart), BPC-157 at its usual 250 to 500mcg, and TA1 at 1.6mg.

Is thymosin alpha-1 FDA approved?

No. It is approved in other countries as Zadaxin. Simms Research supplies it for laboratory research only.