How do I model twelve months of survodutide across supply routes?

I would rather spend on verification than on volume.

Please show the division. I want to check my own against yours.

I would like the general form as well as the specific number, so I can apply it again.

How many significant figures are actually justified here?

Twelve months is 52 weekly administrations across 365 days, and on a four-week ladder from the bottom of the range about 5 steps — so roughly 20 of the 52 doses are escalation doses and 32 are at maintenance. Model it in that order and the routes become comparable: doses per year first, milligrams per dose second, cost per milligram third. Anything quoted per vial hides the second of those, which is the one that changes most between the first 20 doses and the last 32. Then add what each route charges that the other does not. A prescription route carries consultation and dispensing fees, spread across the 52 doses rather than paid once. A research route carries testing, shipping, and the material lost between them. Testing is the line most sheets omit. At one lot a quarter, a test-every-lot policy is 4 assays a year; at one lot a month it is 12. That difference is usually larger than any difference in price per milligram, and it is a policy you choose rather than a cost you are quoted. Put doses per year in the top row and derive everything under it, and the twelve-month totals compare on arithmetic instead of on presentation.

Testing cost per milligram falls sharply with order size, which is the main argument against very small repeat orders.

Wastage from a reconstituted vial discarded at the end of its in-use period is a genuine cost, and it is a function of the diluent volume chosen at reconstitution rather than of anything the supplier did.

Carriage amortises across the order. Twenty-five pounds of carriage on one vial is £2.50/mg on a 10 mg vial; on ten vials it is £0.25/mg. That single term explains most of the case for larger, less frequent orders.

Independent testing prices at the services this community uses are published and are stable enough to model.

Nothing here is medical advice, and research-use compounds are not approved for human use.

Larger orders are cheaper per milligram and concentrate lot risk. Price both.

This is a spreadsheet question and doing it properly changes conclusions more often than people expect.

Change one number and it reverses: if B assays at 82 per cent, that is 8.2 mg for £52, or £6.34/mg, and the cheaper vial is now the more expensive peptide.

Dead-space loss is small with fixed-needle insulin syringes — a few microlitres per draw — and substantial with detachable-needle luer syringes at 35 to 100 microlitres. Across twenty draws that is up to two millilitres of solution.

Divide by measured content, not by label claim. That is the whole correction.

Wastage from expired reconstituted vials is a real line item and nobody includes it.

Worked example. Supplier A: £60 for a 10 mg vial, content 96 per cent, so 9.6 mg for £60, or £6.25/mg before carriage. Supplier B: £52 for the same nominal vial, content 88 per cent, so 8.8 mg for £52, or £5.91/mg. B still wins here, but the gap has narrowed from thirteen per cent on the label to five per cent in reality.

The full calculation: (unit price + carriage share + testing share) ÷ (nominal mg × measured content fraction × (1 − dead-space and wastage fraction)). Every term after the first is routinely omitted.

Published content assay results across the independent services show nominal and measured content differing by one to ten per cent, which is the term that makes label-price comparisons unreliable.

Decide whether you are optimising cost or confidence before you build the model.

edited 18 Apr 2026 by Dr_Bram_Verhoeven — added the citation requested in comments