What a micro test actually covers — and why every lot should have one.

Ask a new brand whether their product has been micro tested and you'll usually get one of two answers: "the supplier sent a COA" or "what's a micro test?" Neither one is going to satisfy a retailer, Amazon, or an FDA inspector. Here's what micro testing is, what the common tests actually check, and how to fit it into your runs without slowing anything down.

What micro testing is — and what it isn't

Micro (microbiological) testing answers one question: is there anything living in this product that shouldn't be? Bacteria, yeast, mold, and specific pathogens like Salmonella.

It's a different question from the other tests brands hear about:

• Identity — is this ingredient what the label says it is?
• Potency — is there as much of the active ingredient as you claim?
• Heavy metals — lead, arsenic, cadmium, mercury.
• Micro — is it clean?

A powder can pass identity and potency with flying colors and still fail micro. They don't stand in for each other.

The tests you'll see most often

Your specification decides which tests apply and what the limits are. These are the ones that show up on most powder supplement and drink-mix specs:

If you don't have limits written yet, USP <2023> (microbiological attributes of nutritional and dietary supplements) is the reference most supplement brands start from. Your customers may have their own requirements on top of that.

Who actually asks for results

• Retailers and distributors — many want a finished-product COA with micro results for each lot before they'll take it.
• Amazon — supplement listings can be asked for testing documentation, and micro is a common part of it.
• The FDA — for dietary supplements, cGMP (21 CFR 111.70) requires finished-batch specifications that include limits on microbial contamination, and you need a way to show each batch meets them.
• Your own customers — the day someone posts that your product made them sick, a clean lot result is the first thing you'll want in hand.

When to test

Every finished lot. One run, one lot number, one micro result. A passing test on last month's lot says nothing about this month's — different ingredient lots, different day, different conditions.

Higher-risk incoming ingredients, too. Botanicals, protein powders, cocoa, and freeze-dried fruit carry more microbial risk than synthetic vitamins or minerals. Testing them before they go into the blender is cheaper than finding a problem in finished goods.

A passing micro result covers one lot. The next lot needs its own.

What it costs at North Lakes

$35 per test, including shipping your sample to the lab. We pull the samples from your run, send them out, and put the results on file with your batch record. We don't mark up lab work.

Allergen testing is separate and priced with your quote, since it depends on the allergen and your product.

Plan for the wait

Micro results aren't instant. The organisms have to be grown out, and pathogen tests like Salmonella typically take longer than plate counts. Two habits keep this from delaying a launch:

• Build the test time into your timeline. Don't book a retail ship date for the day after your run.
• Hold the lot until results are back — especially for anything going to a retailer or Amazon. Shipping first and testing later is how a bad result turns into a recall instead of a re-run.

What happens if a lot fails

The lot stays on hold. Depending on the result, the next steps are a retest to rule out a sampling or lab issue, then an investigation into where it came from — usually an ingredient lot. Failed product doesn't ship. That's exactly why testing before release is so much cheaper than testing after.