Should I get fasting insulin or HOMA-IR?

They're not either/or. HOMA-IR is computed from a fasting insulin plus a fasting glucose, so the practical answer for most people is to order fasting insulin and fasting glucose together — then you have both the raw insulin and the HOMA-IR score.

What is the Kraft test?

An oral glucose tolerance test with insulin measured at several time points (typically 0, 30, 60, 120 minutes), not just glucose. It can reveal an exaggerated insulin response — early insulin resistance — while your fasting insulin still looks normal. Most labs only run glucose, so you have to ask for insulin levels or use a specialty lab.

When is C-peptide the right test?

C-peptide is released one-to-one with your own insulin but isn't present in injected insulin, so it reflects how much insulin your own pancreas is making. It's the test of choice if you're on insulin therapy or being assessed for a secretion problem, rather than for routine insulin-resistance screening.

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Which insulin test should I order?

Fasting insulin, HOMA-IR, an insulin-assayed OGTT, or C-peptide — the right one depends on why you’re testing. We sell nothing, so this just routes you to the test that fits your situation and the cheapest way to get it, doctor or no doctor.

1. Why are you testing?

2. Will a doctor order it for you?

Answer the two questions and we’ll point you to the right test — and the cheapest way to get it.

For the full picture — how to read the result and what actually lowers insulin — see the fasting insulin guide.