Cost per mg: comparing quotes that are written differently

GLP-1 pricing is quoted in at least four incompatible ways: a list price per pen pack, a self-pay program price per month at a fixed dose, a compounded price per vial of some total milligrams, and a subscription price that bundles visits with medication. The cost per mg calculator puts them all on one scale. This guide explains how, and where the comparison can mislead.

The normalising step

Every quote can be reduced to three numbers: what you pay at once, how many milligrams that buys, and how many milligrams you use per week.

• Price per mg = price / total mg in the container.
• mg per month = weekly dose x 4.333.
• Monthly cost = price per mg x mg per month.

A "container" is whatever the price attaches to. For a vial it is the vial. For a brand pen pack it is the pack, and total mg is the sum across the pens (a four-pen pack of 2.4 mg pens is 9.6 mg). For a program priced per month at a fixed dose, the container is one month and total mg is the weekly dose times 4.333.

Why 4.333 and not 4

A month is 52 weeks divided by 12, which is 4.333 weeks. Quoting a weekly product at four doses a month leaves out 4 doses a year, about 7.7 percent of the annual cost. Programs that bill monthly for four pens are not wrong; you simply buy a fifth pack four times a year, and the annual comparison has to include it.

Exact versus whole containers

The calculator has two modes. Exact charges you for the fraction of a container you use in a month; it is the fair per-mg comparison. Whole rounds up to the containers you would actually buy in a month, which is what your card gets charged when a vial cannot be split across billing periods or the remainder expires. Compare in exact mode first, then switch to whole mode to see which option's packaging penalises you at your dose.

Where waste hides

• Titration. Monthly cost rises with each dose step. A quote that looks cheap at 2.5 mg may not be at 10 mg. Run the calculator per step, or use the total-mg figure from the schedule generator across a whole titration.
• Beyond-use dates. A vial dispensed with a 28-day beyond-use date and a dose that uses half of it per month wastes the other half. Whole-container mode captures this; exact mode does not.
• Draw-up and priming loss. A little product stays in the needle hub and syringe each time. It is small per dose and real per year, and no simple calculator models it.
• Fixed fees. Consultation fees, shipping and membership charges are part of the cost of the drug reaching you. Add them to the container price if you want the true figure.

What the calculator does not know

It has no prices in it. That is deliberate: list prices, program prices and compounded prices all change, and a stale built-in number is worse than none. Enter your own quotes with the date you got them. For dated brand and program prices with sources, the FormBlends GLP-1 cost report is maintained separately, and it links to FormBlends' own products, so read it as a vendor's report.

Two things the per-mg figure cannot tell you: whether a compounded product and a brand product are equivalent (they are not interchangeable, and compounded products are not FDA approved), and whether the cheaper option is the right one for you. Price per mg is a fact about the quote, not about the medicine.