Severe deficiency can contribute to fatty liver changes, which is one reason choline gets framed as liver support. Details are summarized in the NIH ODS Choline fact sheet for health professionals
This has happened before, at least twice, and when it has it has represented periods in time where anti-doping and regulators were scrambling to catch up to illegal drugs or substances that had become mainstream
Sometimes combined with microneedling for even deeper penetration
An undated COA, a COA from the same company rather than an independent lab, or a COA that does not specify the batch number is insufficient
For long-term projects, purchasing larger quantities from trusted sources offers better value per milligram, provided proper storage conditions are available
Found in human blood plasma, it declines with age