The Active Site

There are tests now that claim to measure how old you really are. Not the number on your birth certificate, but your biological age, the idea being that two people born on the same day can be aging at different speeds...

For decades the reassuring story about tattoos was that the ink stays put: a permanent mark, sealed in the skin, chemically done with your body. It isn't. Pigment migrates out of the skin and lodges in your lymph nodes...

For most of a decade, vitamin D came with a warning: take it on its own, and the calcium it raises ends up in your arteries instead of your bones. The fix, supposedly, is vitamin K2. The claim is unusually specific for...

For most of the last century, apigenin was a footnote — a yellow pigment in chamomile and parsley, studied mostly by people cataloguing the antioxidants in plants. In the last few years it has become one of the...

For decades, magnesium sat in the supplement aisle as a mineral for muscle cramps, sleep, and general nutrition. Around 2010, that changed. A branded form called magnesium L-threonate launched on the back of a 2010 MIT...

For thirty years, the supplement aisle has sold fish oil as one of the simplest decisions you can make for your brain. In 2026, two research teams on opposite sides of the world published papers that complicate that...

PREFACE: This is an explanation of the debate the guidelines have stimulated. It references the data used to rationalize the guidelines and the data used to oppose them. There is nothing here that was not cited by the...

Omega-3 supplements are at the center of a controversy regarding their oxidation levels and potential harm. This presentation addresses the gap between claims of harm and the available human data, explaining how...

Nutrients are usually studied in isolation, yet synapses don’t operate that way. This episode examines research showing that coordinated nutritional inputs can reshape synaptic proteins and neural firing patterns...

L-arginine is usually treated as a simple nitric-oxide precursor, a molecule with a narrow vascular role. But across multiple lines of research, it keeps appearing in places it shouldn’t: improving cerebral blood flow...

Parkinson’s is often framed as a brain-first disorder, but some of its earliest changes unfold in the gut. This episode unpacks a global metagenomic analysis showing that two surprisingly ordinary microbial compounds...

A new brain-imaging meta-analysis has uncovered the first consistent biochemical signature across multiple anxiety disorders (a shift in a single molecule that moves in the opposite direction of every major psychiatric...

Magnesium salts are often marketed as if they target specific tissues - i.e., “threonate for the brain,” “glycinate for calm,” “taurate for the heart.” Part 2 breaks down what the evidence actually shows: animal studies...

Magnesium supplements are marketed like different compounds with different biological targets - i.e., “for sleep,” “for the brain,” “for stress,” “for energy.” But the foundation of these claims depends on chemistry...

A medication used by millions (including off-label usage for “longevity” purposes) may alter the fundamental pathways responsible for exercise adaptation. This episode reviews new 2025 data showing reduced improvements...