The dispute in plain English
In the wrongful-death lawsuit brought by Kathleen Moller after the death of her daughter Harmony, JOpen, LLC asked the federal court to exclude testimony from plaintiff’s pharmacology expert, Dr. Christopher Williams. The product at issue was O.P.M.S. Silver kratom. The motion was filed March 2, 2026, in a case originally filed in 2024.
JOpen argues that Williams’s discussion of 7-hydroxymitragynine (7-OH) concerns synthetic products rather than the natural kratom product in this lawsuit. Williams’s written report, however, also discusses mitragynine in kratom and the conversion of mitragynine into 7-OH after consumption.
At a glance
- The expert: Christopher Williams, PhD, professor of pharmacology at Xavier University.
- The question: Are opioid and cardiac mechanisms discussed in the expert report relevant to natural-leaf kratom?
- What the defense seeks: Exclusion of Williams’s testimony under Federal Rule of Evidence 702.
- What these records do not show: A signed court order granting that request or a final determination of liability.
Five findings legislators should not overlook
1. Mitragynine from kratom can become 7-OH inside the body. Williams explains that 7-OH is a minor constituent of leaf extracts but can also be formed through liver metabolism of mitragynine. His report cites human pharmacokinetic findings to argue that what is present in the package is not the full story about exposure after ingestion. Expert report, PDF pp. 3–4.
2. Kratom alkaloids act on opioid receptors. Williams describes mitragynine as a partial mu-opioid receptor agonist and 7-OH as substantially more potent in certain experimental analgesia models. These are experimental potency comparisons, not equivalent human dosing instructions or proof that a leaf product has the same effects as a pure compound. Expert report, PDF pp. 3–4.
3. Respiratory effects deserve attention. Williams discusses animal research reporting respiratory depression from 7-OH and different effects from mitragynine. He argues that metabolic conversion matters when considering whole-kratom exposure. The cited animal findings do not establish the frequency of respiratory depression among human kratom users. Expert report, PDF p. 4.
4. Potential heart-rhythm risks. Williams cites experimental work on cardiac potassium channels and an adverse-event reporting study concerning ventricular arrhythmias and cardiac arrest. Adverse-event reports are safety signals, not proof of causation or incidence. Expert report, PDF pp. 4–5.
5. Interactions with other drugs. Williams discusses possible interactions with antihistamines and other drugs affecting the heart or central nervous system. In Harmony Moller’s case, he identifies diphenhydramine and promethazine concentrations and explains his concern about combined effects. Expert report, PDF p. 5.
What the experts actually said: seven source-by-source findings
The most useful evidence is not a slogan about “natural” versus “synthetic.” It is what these experts said under oath or in their filed reports about opioid activity, metabolism, cardiac effects, interactions and the limits of the available evidence.
These excerpts come from exhibits to JOpen’s motion to exclude Christopher Williams. Several witnesses were offered by the defense and disagree with the plaintiff’s theory. Each item links to its original court-filed PDF.
PACER 237-2 · Christopher Williams, pharmacology expert
The strongest affirmative pharmacology evidence
Williams describes mitragynine as a partial mu-opioid receptor agonist and explains that liver metabolism produces 7-OH. He cites experimental respiratory effects, inhibition of cardiac potassium currents, and potential interactions with antihistamines. His discussion of Harmony Moller identifies diphenhydramine at 64 ng/mL and promethazine at 18 ng/mL and raises the possibility of combined cardiac effects.
What it does not prove: His conclusions about mechanisms and interactions do not establish how frequently these outcomes occur in people using kratom.
PACER 237-3 · Christopher Williams, sworn deposition
An important limitation to the potency claim
Williams confirms that his comparison describing 7-OH as tenfold more potent than morphine refers to purified, experimentally administered 7-OH, not the amount present in ordinary leaf.
What it does not prove: The purified-compound potency figure must not be presented as the potency of kratom powder.
PACER 237-4 · Marilyn Huestis, sworn deposition
Limits of the toxicology investigation
Huestis says the testing could have been broader and did not include all novel psychoactive substances. She also disputes attributing death to kratom at the reported concentration, referring to her human dosing study and a published concentration comparison.
What it does not prove: This is principally defense-favorable testimony, not an admission that kratom caused the death.
PACER 237-5 · Christopher McCurdy, sworn deposition
A conceded cardiac signal, with a dose qualification
Asked whether a cited study identifies cardiovascular risk from regular kratom use in the form of prolonged QTc, McCurdy responds, “At the levels that were reported, yes,” and immediately notes those were very high levels. The exchange also identifies the case concentration as 150 ng/mL.
What it does not prove: The testimony does not establish the same risk at the lower concentration in this case.
PACER 237-6 · Edward Boyer, sworn deposition
A narrow evidentiary basis for a redistribution example
In discussing a paper involving 51 deaths, Boyer identifies a patient with a roughly threefold difference between hospital and femoral blood mitragynine measurements. Questioned further, he agrees the cited example is one patient among 51.
What it does not prove: One example does not establish the size of postmortem redistribution in Harmony Moller.
PACER 237-7 · Jack Henningfield, defense expert
The defense acknowledges some abuse potential while disputing the level of risk
Henningfield states that kratom should not be classified as an opioid or dangerous controlled substance, and argues that fatal risk is rare. His report nonetheless acknowledges that some people may abuse kratom and become addicted, comparing the issue with other consumer substances.
What it does not prove: This is a defense report arguing against high risk, not an endorsement of the plaintiff’s causation theory.
READ SOURCE · PDF pp. 5–6 (report numbered paragraphs 22–25) →
PACER 237-8 · Coroner records exhibit
Primary medical records require careful interpretation
This exhibit contains scanned coroner materials. It should be read alongside the medical experts’ competing opinions rather than treated as a standalone finding resolving the dispute.
What it does not prove: No additional numerical or medical claim is drawn from the image-only pages without independent verification.
What the expert actually concluded
Williams states that his assignment was to explain pharmacological mechanisms, not to independently determine cause of death. He agreed with the reported cause-of-death assessment and with other plaintiff experts. That distinction matters: his report is mechanistic expert testimony, not a clinical trial or a court ruling.
What the defense says
JOpen argues that the disputed testimony conflates natural kratom with synthetic or purified 7-OH products, and that the small proportion of 7-OH naturally present in leaf makes testimony about 7-OH misleading in this case. It asks the judge to exclude the expert’s opinions under the rules governing reliable and relevant expert evidence.
That is a litigation position. The filings include deposition excerpts from several experts and a defense expert report. Readers should not treat the motion, the exhibits, or an unsigned proposed order as a decision by the court.
Read the original PACER records
All eleven PACER PDFs are linked below using their original docket-number filenames in the central OPMS document archive.
Why this matters for kratom legislation
A policy that distinguishes leaf products from concentrated 7-OH products must still confront the pharmacology of mitragynine itself, including its metabolic conversion after consumption. This expert report offers a specific scientific argument for why product composition alone cannot answer every safety question.
It does not establish that all kratom use is fatal, that every kratom product produces the same exposure, or that the defendant is liable. Those questions require evidence beyond this motion.
Source and status: Kathleen Moller v. Martian Sales, Inc. et al., No. 2:24-cv-00228-WBV-DPC, Eastern District of Louisiana, PACER Document 237 and attachments, filed March 2, 2026. Expert opinions and disputed legal arguments are attributed to their authors. The included proposed order is unsigned.