What a dose actually costs

A vial of semaglutide arrives priced at $1,200. It holds 10 mL. Your compounding pharmacy tells you that is $120 a millilitre, your spreadsheet records $1,200 against the month it arrived, and everyone moves on.

Three weeks later somebody asks what a weight loss visit earns. The honest answer is that nobody in the building knows, and the reason is not laziness. It is that the vial and the visit have been kept in two different systems that never speak.

The number that is missing

Revenue is easy. It comes off the card terminal, it lands in the practice management system, and it is the number everyone quotes. A $400,000 month is a $400,000 month.

Cost of goods is where it gets slippery, because the cost is not attached to anything. It is attached to a delivery, and the delivery is attached to a date, and the date has nothing to do with the visits the product was used on. So the practice ends up with a monthly total for product spend and a monthly total for revenue, subtracts one from the other, and calls the difference margin.

That figure is not wrong exactly. It is just useless for any decision you would actually want to make. It cannot tell you whether the weight loss programme is carrying the IV suite or the other way around. It cannot tell you whether the $99 membership is profitable. It cannot tell you which of your two injectors is quietly using half again as much product per visit.

Cost per unit dispensed

Start with the vial and work forwards.

Say a 10 mL vial at $1,200. A typical maintenance dose draws 0.5 mL. That is 20 doses in the vial if nothing goes wrong, so $60 of product per dose.

Now put the real world back in. The vial has a 28-day beyond-use date once punctured. If you get through 14 doses before it expires and discard the rest, you did not pay $60 a dose. You paid $85.71, and the difference — $360 — did not appear anywhere in your revenue. It appeared as an unremarkable line in next month's order.

That gap is the whole game. The dose costs what the vial cost divided by the doses you actually got out of it, not by the doses it theoretically held.

A vial's cost per dose is set on the day you throw it away, not the day you open it.

Where the leftover goes

There are only three places product goes: into a patient, into the bin, or unaccounted for. Most practices track the first and discover the other two at inventory count.

Splitting them apart matters more than it sounds. Expiry is a purchasing and scheduling problem — you bought too much, or you did not cluster the appointments tightly enough to finish the vial. Unaccounted-for product is a counting problem, or occasionally something worse. Both of them reduce margin identically, and they have nothing else in common. Rolling them together into "cost of goods" means the number goes up and nobody can say which lever to pull.

A worked month

Take a small weight loss programme. Say four vials at $1,200, so $4,800 of product. Say 62 doses actually administered at $250 a visit, so $15,500 of revenue.

The lazy arithmetic: $15,500 less $4,800 is $10,700, a 69% margin. Good month.

The real arithmetic: four vials should have yielded 80 doses. You administered 62. Eighteen doses — $1,080 — went in the bin. The product that actually met a patient cost $3,720, so the service is running at a 76% margin and the waste is a separate $1,080 problem sitting next to it.

Same $10,700 at the bottom. Completely different conversation. The first version tells you the programme is fine. The second tells you the programme is excellent and your ordering is off by roughly a vial a month.

Price changes and the past

One more trap, and it catches the practices that are otherwise doing this well.

The pharmacy raises the price to $1,400. Whoever maintains the costing sheet updates the number, because that is what updating a number means. And with one keystroke, every visit in every prior month is now costed at $1,400, and last quarter's margin quietly changes.

Cost has to be frozen at the moment of the sale. The dose given in March came out of a $1,200 vial and it cost what it cost. A March report you run in July should say exactly what it said in April, or it is not a report — it is an opinion that drifts.

What to do on Monday

You do not need software to start. You need three columns you probably are not keeping:

• What each delivery cost, per lot, not averaged across the year
• Which lot each dose came out of
• What was discarded, separately from what was used

That is enough to compute honest cost per dose and honest margin by service line. It is tedious by hand, and it is tedious in a way that stops being done by about week six — which is the actual reason most practices do not have these numbers, rather than any disagreement about whether they would be useful.

Vesyra does this part: the sale draws stock down by lot, at the price of that specific delivery, and freezes it onto the visit so a later price change cannot rewrite a closed month. But the arithmetic above is the point, and it is true whether you run it in our software, in someone else's, or in a spreadsheet you maintain yourself.