Semax Vial Size Guide: 5 mg to 30 mg Vials

Semax vials are labeled in milligrams, but the number that actually matters for planning a research protocol — how many doses a vial holds — depends on more than the label. This Semax vial size guide separates what vial size sets (total mcg available) from what a per-draw dosage chart shows (the units for a single draw), and works through the arithmetic connecting vial size, water volume, and target amount to a real doses-per-vial count. It is written for research and educational purposes only and is not medical advice.

The common Semax vial sizes

Research suppliers most often list Semax in three sizes:

Vial size	Typical use case
5 mg	Shorter research runs, or lower per-draw amounts
10 mg	Mid-length runs, or fewer vials for a moderate amount
30 mg	Longer runs, or fewer total vials needed

All three are lyophilized powder, and all three follow the identical reconstitution formula: concentration equals vial mass divided by the bacteriostatic water added. See the Semax reconstitution calculator guide for the full mixing walkthrough — nothing about that formula changes between sizes; only the total mcg available differs.

Vial size sets total mcg, not the size of one draw

This is the point a Semax vial size guide exists to make clear: vial size sets the total amount of Semax available across the whole vial, not how large a single draw is. A 250 mcg draw is a 250 mcg draw whether it comes from a 5 mg vial or a 30 mg vial. What changes is how many 250 mcg draws the vial can supply before it's empty.

The formula:

Doses per vial = vial mass (mcg) ÷ target amount (mcg)

Vial labels are in milligrams while target amounts are typically described in micrograms, so the first step is converting: 1 mg equals 1000 mcg. A 5 mg vial holds 5000 mcg, a 10 mg vial holds 10,000 mcg, and a 30 mg vial holds 30,000 mcg.

Worked example: doses per vial at a 250 mcg target amount

Compare all three sizes against a fixed 250 mcg target amount:

• 5 mg vial: 5000 ÷ 250 = 20 doses
• 10 mg vial: 10,000 ÷ 250 = 40 doses
• 30 mg vial: 30,000 ÷ 250 = 120 doses

Each step up in vial size adds doses in direct proportion, because the target amount didn't change. This holds no matter how much bacteriostatic water goes into any of the three — water volume changes the concentration and therefore the mL and unit reading per draw, but it never changes the total mcg in the vial or the total number of doses that mcg supports.

Water volume changes the draw, not the count

To see that water volume is a separate variable from vial size, reconstitute the same 10 mg vial two different ways and compare a 250 mcg draw:

Vial size	Water added	Concentration	250 mcg draw (units, U-100 syringe)	Doses per vial
10 mg	2 mL	5000 mcg/mL	5 units	40
10 mg	4 mL	2500 mcg/mL	10 units	40

Step through the math for the second row. Concentration: 10,000 mcg ÷ 4 mL = 2500 mcg/mL. A U-100 syringe divides 1 mL into 100 units, so mcg per unit is 2500 ÷ 100 = 25 mcg. Units for a 250 mcg draw: 250 ÷ 25 = 10 units.

Both rows come from the identical 10 mg vial and the identical 250 mcg target amount, so both hold exactly 40 doses. Water volume only changed the unit reading on the syringe — 5 units versus 10 units — which is a question of what reads clearly on the barrel, not a question of total supply.

Matching vial size to a research protocol

Because doses per vial follows directly from vial mass and target amount, sizing a vial — or a combination of vials — to a planned protocol length is a matter of running the formula backward:

Total mcg needed = number of planned doses × amount per dose (mcg)

Worked example. A protocol using a 250 mcg amount once daily for 90 days calls for 90 doses. Total mcg required: 90 × 250 = 22,500 mcg (22.5 mg). A single 30 mg vial supplies 30,000 ÷ 250 = 120 doses, enough to cover the full 90-day run with 30 doses to spare. Two 10 mg vials total 20 mg (20,000 mcg), supplying only 20,000 ÷ 250 = 80 doses — 10 doses short of the 90 needed. Three 10 mg vials (30 mg total) match the single 30 mg vial exactly at 120 doses, which is the point worth pulling out: what determines coverage is total mg, not how many vials that mg is split across.

Why a dosage chart won't answer this

A per-unit dosage chart shows what a single draw looks like in mL and syringe units at a given concentration — useful at the moment of actually drawing an amount. It doesn't show how many draws a vial has left, because that's a function of vial mass and target amount, not concentration. Both questions use the same underlying numbers but answer something different, which is why a vial size guide and a dosage chart stay separate documents rather than one long page.

Common mistakes

• Assuming a bigger vial means a bigger single draw. Vial size sets total supply, not draw size. The target amount sets draw size.
• Forgetting that water volume doesn't change total doses. It changes the mL and unit reading per draw, not how many draws the vial holds.
• Ordering by vial count instead of total mg. Three 10 mg vials and one 30 mg vial contain the same total Semax — plan around milligrams, not the number of boxes.
• Mixing up mg and mcg when comparing a vial label to a target amount. 1 mg equals 1000 mcg, and Semax vials are labeled in mg while research amounts are usually described in mcg — the single most common source of a miscalculated doses-per-vial count.

Use the calculator

The doses-per-vial and total-mg math above is simple division, so a calculator isn't strictly necessary for it. Where a tool earns its keep is the per-draw conversion: enter a vial size, water volume, and target amount into the peptide dosage calculator to get the exact mL and syringe units for that specific draw, or run reverse mode to find the water volume that lands a given amount on a whole unit mark. For the full reconstitution walkthrough and a concentration table across all three vial sizes, see the Semax reconstitution calculator guide.