Cost per mg and Cost per Draw: How to Compare Peptide Vials on Price

Vial prices are not comparable on their own, because vials come in different masses and listings come in different pack sizes. The comparable figure is cost per mg, and from it, cost per draw. Both are two-step arithmetic. This guide gives the formulas, works a 5 mg vial against a 10 mg vial, shows how to handle multi-vial packs and shipping, and ends with the one rule that keeps the comparison honest: compare mass, not vials.

The formulas

Cost per mg = vial price ÷ mg in the vial.

Cost per draw = cost per mg × mg per draw.

The second formula has an equivalent form that is sometimes easier: cost per draw = vial price ÷ draws per vial, where draws per vial = mg in the vial ÷ mg per draw. Both give the same figure, and running both is a quick check.

Keep the mass unit consistent. If the draw is described in mcg, convert it to mg by dividing by 1,000 before multiplying: 250 mcg is 0.25 mg.

Worked comparison: a 5 mg vial at $40 vs a 10 mg vial at $70

The 10 mg vial costs more, so it looks more expensive. Per mg it is the other way around.

	5 mg vial	10 mg vial
Price	$40.00	$70.00
Cost per mg	$40 ÷ 5 = $8.00	$70 ÷ 10 = $7.00
Draws of 250 mcg (0.25 mg)	5 ÷ 0.25 = 20	10 ÷ 0.25 = 40
Cost per 250 mcg draw	$8.00 × 0.25 = $2.00	$7.00 × 0.25 = $1.75
Check: price ÷ draws	$40 ÷ 20 = $2.00	$70 ÷ 40 = $1.75
Cost per 500 mcg draw	$8.00 × 0.5 = $4.00	$7.00 × 0.5 = $3.50

The 10 mg vial is $1.00 per mg cheaper, which is 12.5 percent less ($1.00 ÷ $8.00). Over 40 draws of 250 mcg, two 5 mg vials would cost $80 against $70 for one 10 mg vial, a $10 difference.

That comparison assumes all 40 draws will be used. If only 20 draws are wanted, the 5 mg vial costs $40 for 20 draws and the 10 mg vial costs $70 for the same 20 draws plus 20 that go unused. The cost per draw actually used is then $40 ÷ 20 = $2.00 against $70 ÷ 20 = $3.50. Cost per mg tells you the price of the material; cost per draw used tells you the price of your plan. Both are worth computing.

Reconstitution does not enter the cost. 10 mg in 3 mL and 10 mg in 5 mL are the same $7.00 per mg; the water changes the draw volume, not the price of the mass.

Multi-vial packs

Listings often show a pack price for 5 or 10 vials, sometimes with the pack’s total mass in the title. Two steps:

1. Divide the pack price by the number of vials to get the per-vial price.
2. Divide the per-vial price by the mg per vial to get cost per mg.

A 10-pack of 5 mg vials at $350 is $350 ÷ 10 = $35 per vial, and $35 ÷ 5 = $7.00 per mg. Written as one step, $350 ÷ 50 mg total = $7.00 per mg, which is the same thing and is the only time the pack’s total mass is the right number to use.

Compared with the single 5 mg vial at $40 ($8.00 per mg), the pack is $1.00 per mg cheaper, matching the 10 mg single vial. Compared with a 10-pack of 10 mg vials at $600, which is $60 per vial and $6.00 per mg, it is $1.00 per mg dearer. The table below lines the four options up.

Listing	Vials × mg	Price	Per vial	Cost per mg	Cost per 250 mcg draw
Single 5 mg	1 × 5 = 5 mg	$40	$40.00	$8.00	$2.00
Single 10 mg	1 × 10 = 10 mg	$70	$70.00	$7.00	$1.75
10-pack 5 mg	10 × 5 = 50 mg	$350	$35.00	$7.00	$1.75
10-pack 10 mg	10 × 10 = 100 mg	$600	$60.00	$6.00	$1.50

A pack price only earns its discount if the vials will be used. Lyophilized vials are stored dry until reconstituted, so an unopened pack is a decision about how many vials you will reconstitute in total, and the per-mg figure applies to all of them equally.

Shipping folded in

Shipping is a fixed charge that attaches to the order, not to the vial. To include it, add it to the order total, then divide by the total mg in the order.

Cost per mg (delivered) = (order price + shipping) ÷ total mg in the order.

For a single 5 mg vial at $40 with $10 shipping: ($40 + $10) ÷ 5 mg = $10.00 per mg. For a single 10 mg vial at $70 with the same $10 shipping: $80 ÷ 10 = $8.00 per mg. For two 5 mg vials in one order: ($80 + $10) ÷ 10 mg = $9.00 per mg. For the 10-pack of 5 mg at $350 plus $10: $360 ÷ 50 = $7.20 per mg.

Shipping widens the gap between small and large orders because the fixed charge is spread over more mass. The $10 charge adds $2.00 per mg to a single 5 mg vial, $1.00 per mg to a 10 mg vial, and $0.20 per mg to the 10-pack. Free-shipping thresholds change this calculation and should be included at whatever the actual charge is, including zero.

The cost-per-mg tool on this site has fields for price, vials, mg per vial, shipping and mg per draw, and reports the delivered cost per mg and per draw for any listing. Good suppliers state the mass per vial on each product page, which is the figure the formulas need.

The rule: compare mass, not vials

Every mistake in price comparison comes from comparing the wrong things. A $40 vial against a $70 vial is a comparison of two prices. A $40 5 mg vial against a $70 10 mg vial is a comparison of $8.00 per mg against $7.00 per mg. A $350 pack against a $40 vial is a comparison of $7.00 per mg against $8.00 per mg.

Two numbers are enough for any listing: the total price including shipping and the total mg including every vial. Divide the first by the second. Then multiply by the mg per draw to get the price of a single draw, and divide the delivered price by the number of draws you will actually use to get the price of your plan. If two listings disagree on which is cheaper depending on which of those three figures you look at, the disagreement is the answer: the cheaper per-mg listing is only cheaper if the extra mass gets used.