Theo Marsh

NMN can raise NAD markers in short trials, but human benefits remain narrow. Here is what the evidence says about dose, safety, and common claims.

Green tea extract may slightly shift weight or lipids, but concentrated products have real liver-injury cautions. Here is how to judge the trade-off.

Zinc matters for immune function, but supplements mainly help when intake is low. The evidence for colds, older adults, and safety is narrower.

Vitamin D is a useful compound with an inflated reputation. It helps regulate calcium and phosphate, and deficiency deserves correction. That does not make a daily capsule a general-purpose longevity drug. The evidence is strongest when supplementation treats a shortage; it becomes much weaker when healthy adults with adequate levels take it to prevent cancer, … Read more

Curcumin has modest evidence for knee osteoarthritis, but absorption tricks and rare liver injury reports make the supplement choice less simple.

Psyllium is one of the rare supplements with a boring mechanism and a useful evidence base. It forms a gel, changes stool texture, and can modestly lower LDL cholesterol. That makes it worth discussing. It does not make the tub on the shelf a heart medicine, a weight-loss treatment, or a substitute for lipid care. … Read more

Probiotic supplements may help in specific situations, but strain, dose, storage, and health context matter more than the CFU number on the label.

N-acetylcysteine has real clinical uses, yet the wellness case for daily capsules rests on thin evidence and a supplement supply chain that is hard to trust.

Berberine may modestly improve blood sugar and lipids, but the evidence is short-term, mixed, and complicated by real drug-interaction risks.

Ashwagandha has some stress and sleep evidence, but liver, thyroid, pregnancy, medication, and product-quality cautions should shape any discussion.