The Signal Report // SUPPLEMENTS
Supplements.
What the studies actually measured versus what the label claims, from a formulator who holds his own category to the bar. All reports →
31 in this beat · page 1 of 4
What the milligrams on a melatonin label mean
"5 mg melatonin" reads like a dose. In a 2023 JAMA lab test, 22 of 25 gummies missed their label by more than 10%, mostly high, from 74% to 347%, and one held no melatonin at all. A Canadian study found lot-to-lot swings of up to 465%. What the label number promises, and what the studies cannot tell you.
Read the report → Report 177 · Supplements · 2026-10-04 · 7 minWhat a probiotic's CFU number counts
"50 billion CFU" is a count of colonies that grew on agar plates in one lab. FDA requires probiotics to be listed by weight, which includes dead cells; the CFU figure rests on 2018 draft guidance. Lab-to-lab limits run up to 0.5 log, about a factor of three, and a 2021 review found more than 40% of products that declared a count fell short. Four questions for any CFU claim.
Read the report → Report 171 · Supplements · 2026-10-01 · 8 minWhat a mushroom polysaccharide number counts
Starch is a polysaccharide too. A 2025 study found grain-grown chaga products were 33 to 68% alpha-glucan versus under 2% for wild chaga, with beta-glucan tracking the oats or rice they grew on. The beta-glucan kit itself warns about grain. Four questions to ask of any polysaccharide claim.
Read the report → Report 164 · Supplements · 2026-09-27 · 10 minWhat an FTIR match actually proves
In April the FDA told a mushroom and herbal supplement maker that FTIR "lacks the specificity" to identify ingredients in blends. It has said versions of that since 2017, and a 2022 letter shows why: lots that matched their reference also matched catnip, calendula and thyme at about 86%. A spectroscopist on what a match score can and cannot prove.
Read the report → Report 158 · Supplements · 2026-09-23 · 11 minThe tejocote that was never tejocote
FDA added three more products to its yellow oleander alert last week, and one of them is not even sold as tejocote. The CDC investigation underneath it tested ten products labelled tejocote root: nine were a cardiac-poison plant, and the tenth contained no tejocote either.
Read the report → Report 153 · Supplements · 2026-09-20 · 10 minThe antioxidant marker that a meal can move
A meta-analysis of seven astaxanthin trials found five oxidative and injury markers unchanged and one improved. That one is advanced oxidation protein products, an assay built for dialysis patients in 1996. A 2007 experiment showed a meal raises it to patient levels, and a 2015 paper found two different assays circulating under the same name.
Read the report → Report 147 · Supplements · 2026-09-17 · 8 minCordyceps raised oxygen use at rest. So what?
A July 2026 PLOS One trial gave 12 young men one gram of Cordyceps militaris and reported higher resting oxygen uptake and faster reactions. Oxygen used at rest measures what the body spends, not what it can do, and peak VO2 did not move. The reaction-time result is real but general, not post-workout, and the paper reports its size three different ways.
Read the report → Report 142 · Supplements · 2026-09-11 · 10 minIs Amanita muscaria legal?
Every Amanita muscaria product page says the same thing: not a controlled substance, federally legal. The first half is true. I checked the DEA listing and the mushroom is not on it. The second half is a claim about the wrong statute. Under the Food, Drug, and Cosmetic Act the FDA has closed the conventional-food pathway and the dietary-supplement pathway, in two separate letters, under two different sections. And in one published analysis, the two products claiming to contain it held no detectable trace of it.
Read the report → Report 135 · Supplements · 2026-09-08 · 10 minDo creatine gummies contain creatine?
Creatine monohydrate powder is close to inert for years. Dissolve it and it starts folding into creatinine, faster as the pH drops. A gummy supplies the water and the heat by construction. The one published brand-by-brand assay found six of twelve missing their label claim, and the failures split into two different problems wearing the same costume.
Read the report → Report 129 · Supplements · 2026-09-05 · 9 minWhich lion's mane did you buy?
Hericenones come from the fruiting body. Erinacines come from the mycelium. A validated method published in February 2026 measures both at once, and the two families turn out to be close to mutually exclusive in commercial products. Its most useful result is not in the results table: it is the screening step, where products with nothing detectable were set aside before quantitation began.
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