How We Test

This page explains who tests what, how a laboratory measures a sample, how to get the certificate for your batch, and what a certificate does and does not prove.

Who does the testing, and for which products

Free Muscle sells its own brand and, through the Muscle Market, products made by other brands. Testing works differently for each.

  • Free Muscle-brand research compounds and food supplements. Every batch is assayed by Janoshik Analytical, an independent laboratory. See the Free Muscle range.
  • Other brands: iMuscle, Yakka Strength, Thoroughbred Labs and BioLab. We do not have these batches assayed by Janoshik. A Certificate of Analysis is available only where the manufacturer supplies one for the batch we hold, and the manufacturer chooses the laboratory that issues it.

Independence matters because a seller that tests its own product is also the party with an interest in the result. You can read more about third-party testing in What Is Janoshik Analytical?

What gets tested

  • Identity. Confirms that the substance in the sample is the substance named on the label.
  • Purity. Measures how much of the sample is the declared compound, and shows what else was detected.
  • Content. Some certificates also report the measured amount of compound per capsule or per unit. Where a certificate includes this, you can compare it with the strength on the label. Where it does not, the certificate speaks to identity and purity only.

Certificates are issued per batch. A certificate from a batch produced two years ago does not describe the pack in your hand.

Common test methods

A certificate should name the method behind each result. Two methods often named are:

  • HPLC (high-performance liquid chromatography). The dissolved sample is pushed through a column that separates its components. A detector records each one as a peak on a chart called a chromatogram. An HPLC purity figure is usually the area of the main peak as a share of the total area of all the peaks detected.
  • LC-MS (liquid chromatography with mass spectrometry). The sample is separated in the same way, and the mass of the molecules is then measured. A measured mass that matches the expected mass of the named compound is evidence of its identity.

Two things follow from this. A purity figure of 98% does not tell you what the other 2% is. It means the main peak made up 98% of what the detector recorded under those conditions. And a purity figure with no stated method is a claim, not a result.

How a certificate links to your pack

A certificate describes one batch, tested on one date. It only describes your product if the batch number on the certificate matches the batch number on your pack. When you ask for a certificate, quote the batch number from your pack, and when it arrives, check that the same number appears on it.

If you cannot find a batch number, email us your order number and the product name.

How to request the certificate for your batch

  1. Find the batch number on your pack.
  2. Email it to freemuscleuk@gmail.com with the product name, and your order number if you have one.
  3. For a Free Muscle-brand product, we send you the Certificate of Analysis for that batch. For another brand's product, we send the manufacturer's certificate for that batch where one has been supplied.

How to read a certificate

When the certificate arrives, work through five checks. Each one is explained in full in How to Read a Certificate of Analysis.

  1. Identity. It matches the compound on your label.
  2. Purity and method. A figure, with the method behind it.
  3. Batch number. The same as on your pack.
  4. Test date. Plausible for the batch you received.
  5. Issuing laboratory. Named on the certificate.

What a Certificate of Analysis does not prove

  • A certificate reports what was measured in the sample tested. It says nothing about whether a substance is safe, effective or suitable for any use.
  • It certifies the sample submitted. Reputable testing depends on the sample being representative of the batch, which is a matter of process discipline, not of the certificate itself.
  • It is not regulatory approval, and it is not a substitute for one. Research compounds are not licensed medicines, whatever their certificate says.
  • It does not make a product lawful to buy, hold or import where you are. Our legal status page explains the UK position for MK-677 and SARMs.

Questions about testing

Email freemuscleuk@gmail.com with any question about testing, batches or certificates. Our contact page lists what to include. Delivery and returns are covered on Shipping and Delivery and our guarantee.

Last reviewed: 27 September 2026.

Research compounds sold by Free Muscle are supplied for laboratory research use only and are not for human consumption. They are not authorised as medicines by the MHRA, EMA or FDA, are not food supplements, and are sold only to adults aged 18 or over. Nothing on this page is medical or dosing advice.