Question: A recent paper makes the claim that 5-HTP products are contaminated with “peak X.” Is this true? What is peak X? And is there cause for concern? ——OTP

Answer: It is true. A recent letter to the editor claims that at least some of the 5-HTP products currently in the market contain very small amounts of an unknown substance which may be associated with cases of EMS (eosinophilia myalgia syndrome). I say “may” because we do not know that peak X is causally related to EMS. Although a tentative structure for peak X has been proposed, it has yet to be confirmed by an independent laboratory. We really are not yet sure just what peak X is.

Since all substances sold in the market have impurities, “peaks” are the rule rather than the exception. All nutrients and drugs, whether they are FDA-approved or not, have impurity peaks, some of which are identified and many of which are unknown. The term “peak” refers to the shape of a curve that comes out of an analytical testing device called a chromatograph. A chromatograph consists of a long, thin tube filled with a polymer or particulate matrix (the packing) and a gas or fluid carrier. It has an injection port at one end of the tube and a detector at the other end. An injected sample of a substance or mixture flows down the tube (through the matrix), carried by the gas (in a gas chromatograph — or GC) or a solvent (in a high-pressure liquid chromatograph — or HPLC). As the sample flows down the tube, the different molecules separate from each other depending on their affinity for the matrix packing. Slippery molecules flow through the matrix rapidly and are the first to emerge. Sticky molecules are slowed down as they pass through the packing and are delayed. At the far end of the tube, a detector measures the separated chemicals as they emerge, producing peaks on the graph paper.

The exact profile of peaks not only depends on the injected sample, but on the choice of packing material, its particle size, the solvent or gas mixture used, the flow rate, the temperature, the pH and many other factors. Often, chemicals with entirely different chemical structures can have similar or identical affinity for a particular packing. This can cause peaks to blend into or superimpose on each other. When testing purified substances (like 5-HTP), the primary peak may be hundreds to tens of thousands of times larger than the impurity peaks. Impurity peaks can get buried under the primary peak. Precise technique is critical. Chromatography is an art as well as a science.

The peak-X impurity measured in six 5-HTP samples was extremely small (a tiny fraction of 1%), so small in fact that the researchers chose not to present their findings in absolute terms (i.e., the actual percentage of impurity). There would have been too many zeroes after the decimal point to be impressive. Instead, they expressed their findings as a percentage of the impurity level found in “case-implicated” 5-HTP samples tested at the same laboratory. When a person comes down with EMS, whatever they were taking is “case implicated.” In other words, “case implicated” is a scientific term for “guilt by association.” The six samples were reported to contain 2.9, 3.4, 6.5, 7.1, 8.7 and 14.1 percent of the amount found in case-implicated samples. Such numbers are far more impressive to reporters and the lay public than 0.029% or 0.71 parts per million.

The exageration of numbers was fully consistent with the blatant political motivations behind the letter. The authors presented their limited data within the context of a rant against the “Dietary Supplement and Health Education Act of 1994” which “deregulated” the FDA’s evaluation of the “purity, safety and efficacy” of dietary supplements. This is a fantasy. The authors’ gross misunderstanding of how the FDA regulated dietary supplements prior to the DS&HEA is profound, and illustrates the mythical nature of the world view in which these researchers operate. Such bias must be considered when evaluating their claims.

Hopefully, now that this issue has received some publicity, we expect that consumer demand will drive the industry towards even lower levels of peak X. ——SWF