Is there an official TB-500 injection frequency?

No. TB-500 has no FDA-approved injectable label, so no regulatory body has set a required schedule. Frequency in research write-ups varies by protocol, not by an approved standard.

Does TB-500 injection frequency change the reconstitution math?

No. Frequency determines how many times a dose is drawn from a vial. Concentration is fixed at reconstitution — vial mass divided by water volume — and stays the same no matter how often a draw happens.

How do I work out how long a TB-500 vial will last at a given frequency?

Divide the vial's total mg by the target dose to get doses per vial, then divide that by how often a dose is drawn. A 10 mg vial dosed at 2.5 mg holds 4 doses — 2 weeks at twice weekly, or 4 weeks at once weekly.

Does a higher TB-500 injection frequency mean a smaller dose?

Not necessarily. Frequency and dose size are separate choices in a research protocol. A protocol can pair a higher frequency with a smaller per-draw dose, or keep the dose the same and simply draw down the vial faster — the arithmetic doesn't force one over the other.

TB-500 Injection Frequency Explained

By PeptCalc Research — Medically reviewed by David Mansour, MD — Last reviewed September 4, 2026

TB-500 injection frequency is not something a drug label specifies, because TB-500 has no approved injectable label to specify it. That puts it in a different position from an FDA-approved peptide, where frequency is fixed by regulatory review. This reference explains what determines frequency in TB-500 research protocols instead, and how frequency interacts with the reconstitution math that decides how long a vial actually lasts. It is written for research and educational purposes only and is not medical advice.

No approved label sets a fixed frequency

TB-500 is the common research name for a synthetic peptide corresponding to a fragment of Thymosin Beta-4 (Tβ4), a naturally occurring protein. Published research on Tβ4 and TB-500 is predominantly preclinical — animal models and cell studies — rather than large, controlled human trials, and TB-500 carries no FDA-approved formulation for any human indication. Without that regulatory anchor, there is no single "correct" TB-500 injection frequency the way there is for a handful of approved peptides — only frequencies that show up across different research write-ups and protocols, which vary from source to source.

That absence of a fixed standard is consistent with how TB-500 is treated elsewhere on this site: there's no official water volume for reconstitution either, only reference concentrations chosen because they read cleanly on a syringe (see the TB-500 dosage calculator guide). Frequency works the same way — a protocol detail set by whoever designed the specific research use, not a number handed down from an approved label.

What frequency actually controls

Frequency answers one question: how many times per period does a draw come out of the vial. It does not answer a separate question: what is the concentration of what's in the vial. That second question is fixed the moment bacteriostatic water is added:

Concentration = vial mass (mg) ÷ water added (mL)

A vial reconstituted to a given concentration stays at that concentration through every draw, whether the schedule calls for one draw a week or several. Frequency and concentration are independent variables that happen to combine into a third, more practical number: how many weeks a single vial will actually cover.

Worked example: vial life at two frequencies

Take a 10 mg TB-500 vial reconstituted with 1 mL of bacteriostatic water — the same reference setup used in the TB-500 loading phase dosage research guide — at a 2.5 mg target dose per draw.

Step 1 — concentration. 10 mg ÷ 1 mL = 10 mg/mL.

Step 2 — volume per dose. 2.5 mg ÷ 10 mg/mL = 0.25 mL.

Step 3 — syringe units. On a U-100 insulin syringe, 1 mL = 100 units, so 0.25 mL × 100 = 25 units per draw.

Step 4 — doses per vial. 10 mg ÷ 2.5 mg = 4 doses. This number depends only on vial mass and dose size — the water volume chosen in Step 1 doesn't change it.

Step 5 — vial life by frequency. At twice weekly, 4 doses run 4 ÷ 2 = 2 weeks. At once weekly, the same 4 doses stretch to 4 ÷ 1 = 4 weeks. Neither frequency is presented here as a recommendation — they're two illustrative points to show how the same vial and dose produce very different vial-life numbers depending on how often it's drawn.

The 5 mg vial follows the identical formula at a lower total. Reconstituted with 0.5 mL of water (also 10 mg/mL, matching the concentration above and giving the same 25 units for a 2.5 mg dose), it holds 5 mg ÷ 2.5 mg = 2 doses. At twice weekly that's 1 week; at once weekly, 2 weeks.

Vial size	Water added	Concentration	2.5 mg dose (units)	Doses per vial	Vial life — twice weekly	Vial life — once weekly
5 mg	0.5 mL	10 mg/mL	25 units	2	1 week	2 weeks
10 mg	1 mL	10 mg/mL	25 units	4	2 weeks	4 weeks

Frequency and dose size are separate decisions

It's easy to assume a higher TB-500 injection frequency automatically means a smaller per-draw dose, since that pattern shows up in some protocols. The arithmetic doesn't require it. A protocol can hold the dose steady and simply draw from the vial more often — which draws the vial down faster and shortens vial life — or it can lower the dose to stretch the same vial across more frequent draws. Frequency, dose size, and vial life are three separate numbers connected by the doses-per-vial formula above; changing one doesn't automatically change another unless the protocol is designed that way.

Why research protocols on frequency disagree

Because there's no approved label to converge around, published and self-reported TB-500 protocols describe a range of schedules rather than one standard. Some describe twice-weekly draws; others space them out to once a week or less. This guide does not recommend a frequency or take a position on which protocol is better — that's a research design question outside the scope of a reconstitution reference, and outside what a peptide calculator can tell you. What the math above can tell you is how any given frequency plays out against a specific vial size, water volume, and dose once you've settled on one.

Keeping frequency and concentration from drifting apart

A frequency-based vial-life estimate is only accurate if the concentration behind it hasn't changed. Track the date a vial was reconstituted, not just when it was opened — see how to store reconstituted peptides for the general reasoning. If a vial that should supply 4 doses at 10 mg/mL runs out sooner than the frequency and dose size predict, the concentration used in the original calculation is the more likely source of the mismatch, not the compound itself.

Common mistakes

Looking for an official TB-500 injection frequency. No approved label sets one — treat any specific number as a protocol detail, not a standard.
Assuming frequency changes concentration. It doesn't. Concentration is fixed at reconstitution; frequency only affects how fast the vial's total mg gets drawn down.
Reusing a vial-life estimate after changing the water volume or dose. The 2-week and 4-week figures above only hold at 10 mg/mL and a 2.5 mg dose. Change either input and the vial-life number changes with it.
Confusing dose size with frequency. They're independent choices, not two names for the same variable.

Use the calculator

Enter your TB-500 vial size, bacteriostatic water volume, and target dose into the peptide calculator to get the exact concentration, draw volume, and syringe units, then apply your intended frequency to the doses-per-vial figure to estimate vial life. For the full mixing steps and reference vial sizes, see the TB-500 dosage calculator guide; for how a loading phase changes frequency over the course of a protocol, see the TB-500 loading phase dosage research guide.