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Understanding protein lab-testing reports

What does third-party tested mean on a protein powder? How to read a lab report, check a lab's NABL accreditation, and see what a test or certification does and does not cover.

KiloCare Team · · How we write and review

The tub has a small QR code beside the words "third-party tested". You scan it, and a one-page report opens on your phone. It is full of numbers, units and short codes.

The words on the tub do not say what was tested. A lab report lists the tests run on one sample of one product.

What a certificate of analysis is

A brand may publish a certificate of analysis, often shortened to CoA. In the World Health Organization's model, a CoA lists the tests done on one sample and the results. It also gives the limit each result was judged against. It then says whether the sample met its specification.[1] That model is written for medicines, not food. It is still a useful guide to what a report should show.

The same model expects the name and address of the lab that issued it, a sample number, and the date the sample arrived.[1] So ask 2 questions first. Who issued the report? And who did the tests: the maker's own lab, or an outside lab?

An outside lab is more independent of the maker. But if the maker chose and sent the sample, the lab tested what it was sent.

Does the report match your pack?

In the WHO model, a CoA is usually prepared for each batch.[1] Look for the product name, the flavour, the batch or lot number and the dates.

Flavours can use different recipes. A report on an unflavoured powder is not evidence about the chocolate one. And a result for one batch does not show that later batches gave the same result.

A report on a different batch can still tell you something about the product. It is less direct evidence about the tub in your hand.

What was tested?

India's food regulator groups food testing as nutritional analysis, contaminants and toxins, and microbiological safety.[2] A protein powder report may include some of these:

  • Protein: how much protein is in the powder.
  • Amino acids: the amount of each amino acid.
  • Heavy metals: named metals such as lead, arsenic or mercury.
  • Microbes: named bacteria such as Salmonella, or total counts.
  • Pesticide residues: the pesticides included in the test.
  • Substances banned in sport: a set list, for athletes in drug-tested sport.

A report covers only the tests it lists. A protein result says nothing about heavy metals. A banned-substance screen does not check the protein on the label.

Protein and amino acids are separate tests. Protein is usually calculated from the nitrogen in the powder, multiplied by a conversion factor.[3] An amino acid profile measures each amino acid on its own. The UN's food agency recommends measuring protein that way whenever possible.[3] Check which method the report names.

A lab measures what is in a powder. It does not study whether the powder changes muscle, weight or health.

How to read the results

In the WHO model, each test has a result and the limit it is judged against.[1] A useful report also names the method and the unit. Here is a made-up report with notes.

A made-up test report

Every value here is invented. It is not a real product, lab or result.

Lab
Example Testing Lab
The lab that did the tests. Check its accreditation, below.
Product
Whey concentrate, unflavoured
Match the product and the flavour to your pack.
Batch
EX-0425
Match the batch number to the one printed on your pack.
Total protein
78 g per 100 g
Compare it with the label's figure per 100 g.
Lead
Less than 0.05 mg/kg
Below the lowest level this method can find. Not the same as zero.
Salmonella
Absent in 25 g
Not found in the 25 g portion tested.
Method and limit
Not shown
This report leaves them out. Ask the maker for the method and the limit for each test.

A number on its own is not a pass or a fail. You need the limit it is compared with, in the same unit. A result in mg/kg cannot be read against a limit in another unit until it is converted.

India's microbiology method reports Salmonella as present or absent in a 25 g portion.[4] So "absent in 25 g" is a result for that portion only.

"Not detected" is not zero

Every test method has a lowest amount it can find. Below that, it cannot tell a small amount from none.

  • Limit of detection: the lowest amount the method can detect, at a stated level of confidence.[5]
  • Limit of quantification: the lowest amount it can measure with acceptable performance.[5]

A European guide to lab methods says a result of "not detected" is uninformative on its own. The report should say what the limit of detection was, or give the result as less than that limit.[5] So "Less than 0.05 mg/kg" tells you more than "Not detected".

What NABL accreditation means

In India, the National Accreditation Board for Testing and Calibration Laboratories (NABL) accredits testing labs to the ISO/IEC 17025 standard.[6]

Accreditation covers a list of tests, methods and ranges, called the scope. NABL says that anything not listed in the scope is not covered by the lab's accreditation.[6] A lab can be accredited for some tests and not others.

Under NABL's rules, accredited tests carry the NABL symbol. Beside it is the lab's certificate number, in the form TC-XXXX. Tests outside the scope go on a separate report.[7] A lab may use the symbol only while its accreditation is valid.[7]

To check a lab, search for it on NABL's website and open its certificate number. You can download its scope and look for the test, the method and the range on your report.[6]

NABL does not test products itself.[6] Its rules say the NABL symbol must not be placed on products that a lab has tested.[7] The symbol is about the lab's competence for listed tests. It is not an approval of a protein powder.

What Informed Choice and Informed Sport cover

Some brands carry the mark of Informed Choice or Informed Sport. Both programmes are run by LGC, an anti-doping lab.[9] Informed Choice reviews the maker's procedures on paper, and tests samples from at least 3 batches before it certifies a product.[8] Each product then has monthly blind tests on samples bought from shops.[8] The programme's site says it is not guaranteed that every batch has been tested.[9]

Informed Sport tests more often. Every batch, including every flavour, is tested before it goes on sale.[9]

Both programmes test for substances banned in sport.[9] Informed Choice says no programme can test for every banned substance.[10] Neither programme says it checks the protein or other nutrients on the label.

Certification is for a product, not a whole brand. Search for the exact product and batch on the programme's own website.

Your checklist for a test report

Use it to read a report that a brand sends you or publishes.

Before you trust a testing claim

If something is unclear, ask the maker. Having no public report does not make a product unsafe. But a testing claim with no report behind it cannot be checked.

Food comes first

India's dietary guidelines say a healthy adult does not need protein powder.[11] If you are still deciding whether to buy one, read our article on whey and plant protein.

On your phone, the top of the report now reads plainly: the lab's name, then the batch.

Speak to your doctor or dietitian before using a protein supplement if you:

  • have a milk or other food allergy
  • have kidney or liver disease, or diabetes
  • are pregnant or breastfeeding
  • take a medicine that reduces your appetite
  • have been told to limit protein
  • are buying it for a child

It means a lab outside the brand tested a sample of the product. Ask for the report. Check which lab, which tests, which product and batch, and what the results were.

No. "Not detected" means the amount was below the lowest level the test method can detect. A useful report states that limit, for example less than 0.05 mg/kg.

No. NABL accredits labs for specific tests. It does not test products, and its rules say the NABL symbol must not be placed on products a lab has tested. Check that the test on your report is in the lab's accredited scope.

Sources

  1. World Health Organization. Annex 4: Model certificate of analysis. In: WHO Expert Committee on Specifications for Pharmaceutical Preparations: fifty-second report [Internet]. Geneva: WHO; 2018. WHO Technical Report Series No. 1010. Available from: extranet.who.intCited atp. 187p. 187p. 187p. 187
  2. Food Safety and Standards Authority of India. Food testing [Internet]. FSSAI; [cited 2026 Oct 14]. Available from: fssai.gov.inCited atTesting content and parameters
  3. Food and Agriculture Organization of the United Nations. Food energy: methods of analysis and conversion factors. Report of a technical workshop. Rome: FAO; 2003. FAO Food and Nutrition Paper 77. Available from: fao.orgCited at§2.1.1§2.1.2
  4. Food Safety and Standards Authority of India. Manual of methods of analysis of foods: microbiological examination of food and water. New Delhi: FSSAI; 2024. Available from: fssai.gov.inCited atSalmonella, Expression of result, p. 203
  5. Cantwell H. Eurachem Guide: The Fitness for Purpose of Analytical Methods: A Laboratory Guide to Method Validation and Related Topics. Eurachem: Eurachem; 2025. 3rd ed.. Available from: eurachem.orgCited at§5.3.1§5.3.4§9
  6. National Accreditation Board for Testing and Calibration Laboratories. Frequently Asked Questions [Internet]. NABL; [cited 2026 Oct 14]. Available from: nabl-india.orgCited atQ31Q30Q25, Q31Q31
  7. National Accreditation Board for Testing and Calibration Laboratories. Policy for use of NABL symbol and/or claim of accreditation by accredited conformity assessment bodies (CAB) & NABL accredited CAB combined ILAC MRA mark. Gurugram: NABL; 2024 Sep 3. NABL 133, Issue 09, Amendment 03. Available from: nabl-india.orgCited at§4.1, §5.1, pp. 4-5§6.6, p. 6§6.10, p. 7
  8. LGC. Informed Choice: certification process [Internet]. LGC; [cited 2026 Oct 14]. Available from: choice.wetestyoutrust.comCited atStages 1-2Stage 4
  9. LGC. Informed Sport vs Informed Choice [Internet]. LGC; [cited 2026 Oct 14]. Available from: choice.wetestyoutrust.comCited atInformed Sport vs Informed ChoiceInformed Choice paragraphInformed Sport paragraphInformed Sport paragraph
  10. LGC. Informed Choice: frequently asked questions [Internet]. LGC; [cited 2026 Oct 14]. Available from: choice.wetestyoutrust.comCited atDoes Informed Choice test for everything on the WADA Prohibited List?
  11. ICMR-NIN Expert Committee. Dietary Guidelines for Indians - 2024. Hyderabad: ICMR-National Institute of Nutrition; 2024. Available from: nin.res.inCited atp. 61, Guideline 8