Is That PEth Result Built for Court? What Attorneys Should Check.

01You can tell the difference — if you know what to look for

PEth (phosphatidylethanol) is one of the most useful alcohol biomarkers in family law because it reflects consumption over roughly the preceding few weeks. But a PEth result can be produced and reported in different ways depending on who it was made for — and a report written for clinical care carries signs that it wasn't built for a courtroom. They're right there on the page. You just have to know where to look.

The first sign is often printed right on the report. A PEth test ordered through a family doctor or run through insurance is a clinical test — and it's common to see these reports say so on their face, identifying themselves as non-forensic and for medical use only. The laboratory isn't hiding anything; it's telling you what the test was built for. Once you know to look for that line, it's the fastest way to know what kind of result you're holding. It doesn't mean the result is wrong — it means it was built for a different job than the one your case needs it to do.

A second sign is subtler, because it looks like more information, not less. "PEth" isn't a single substance. According to the Society of PEth Research, roughly 48 distinct PEth analogs have been identified in human blood — and they are not interchangeable or equally meaningful as evidence of drinking. Two of them, PEth 16:0/18:1 and PEth 16:0/18:2, are the most abundant, and a clinical report may list both. So a result can land on your desk showing more than one PEth value, each with its own number, both compared to the same range. To a physician, that's a familiar readout. To an attorney or a judge, it's two numbers and a question the page doesn't answer: which of these is the one that matters?

Between them, those two signs tell you most of what you need. Whether a report labels itself clinical, or hands you several values with no guidance, the real question underneath is the same: was this result built to answer what the court is asking?

02Why this happens — and why it isn't a defect in the test

There's nothing wrong with a clinical PEth report. It exists because a large share of PEth testing is ordered for medical or consumer health purposes, and it's written for the reader it was built for: a healthcare provider who can look at the full set of values and know, from training, which analog carries the weight and what the pattern means.

That reader isn't you. And it isn't the judge.

When a report designed for a clinician lands in a family court file, the specialized knowledge it assumes doesn't come with it. The report shows the values; it does not tell the legal decision-maker which value is the pertinent marker of alcohol consumption, because it was never meant to. Deciding which PEth analog is the relevant one, and what a given level signifies, is laboratory interpretation — the work of a qualified toxicologist. It is not the attorney's job, and it is not something a clinical report resolves for you. It simply hands you the panel and assumes someone qualified is reading it.

03Head it off before your client tests

Knowing the signs matters most before a result exists — because the most common way a case gets undermined early is a well-meaning client trying to be efficient. Faced with a testing order, the temptation is strong: just ask the family doctor, run it through insurance, and hand you the result. It's cheaper and it feels responsible — and it produces exactly the clinical report described above, often with no documented chain of custody.

The time to head this off is at the first conversation, before any specimen is collected. Once a client has already tested through their doctor, your options narrow to whatever that report can and can't support.

04What a forensic collection is built to do differently

A forensic PEth collection starts from a different question. Not "what is this person's full clinical picture," but "what does the court need to know about alcohol consumption, and how do we produce a result that answers exactly that?"

That shapes what gets reported. A forensic result is built to speak to the specific analog the science uses to classify drinking behavior — reported as the pertinent marker, for the reader who has to make a legal decision rather than a medical one. The point isn't more data. It's the right data, framed for the question actually in front of the court, so the person relying on it isn't left guessing which number is the evidence.

05Wherever your client is, the collection can be done right

You do not have to be in our area — or send your client across the state — to get a forensic PEth collection. TrueTest arranges collections nationwide through an established collection network:

• An electronic order, routed to a site near your client. We create the order; your client is given an authorization number and directed to a collection location close to them. A collector there takes the specimen and sends it to the laboratory under a documented chain of custody.
• Or a collection kit sent directly. When it's the better fit, we ship a kit and coordinate the collection so the specimen is taken and returned correctly.

Either way, it's a straightforward blood specimen — by draw or finger-stick, depending on what's convenient for your client — and either way, the part that actually matters travels with it: a chain of custody set up correctly from the first step, by people who know where these collections go wrong. That anticipation is the difference between a result you can account for and one you have to defend.

06Where TrueTest fits — and where it doesn't

This is worth being precise about, because it's the line that keeps our word credible when a result is challenged.

TrueTest Labs is a nationwide drug and alcohol testing provider. Part of what sets us apart is that we perform collections ourselves — so we know, from doing the work, which test fits which circumstance and where these collections go wrong. When a collection is ours, we can also testify as a fact witness to how it was performed, if that's ever questioned.

What a given PEth level means, and which analog governs, is interpretation, and that belongs to the accredited laboratory. When a case turns on the science, the laboratory can provide qualified toxicologists for interpretation letters or testimony, arranged directly with the lab. We keep collection and interpretation in separate hands on purpose — it's what lets each stand on its own when a result is challenged.

We're not here to tell you how to read a level. We're here so that when the result reaches you, it was collected correctly and reports the thing the court is actually asking about.

07The practical takeaway

If a client brings you a PEth result you can't fully parse, that's not a failure on your part — it's a report written for a different reader. And the way to avoid being handed one is to set up the testing correctly before it happens, so the result you receive is built for the courtroom from the start — wherever your client happens to live.

If you'd like to arrange a collection for a client, or make sense of a report one has already handed you, we're glad to help. We'll set up the order, get your client to a collection site near them, and where the science itself is at issue, point you to the laboratory's interpretation resources.