What's Not Worth Buying
Red flags in the supplement industry
This closing section is deliberately about what to skip — a supplement industry built partly on genuine science and partly on marketing benefits from readers being unable to distinguish the two.
The Common Red Flags
Proprietary "blends" with undisclosed individual doses — if you can't see the dose of each ingredient, you can't compare it against the evidence at all, which is often precisely the point of hiding it.
Testosterone "boosters" — the Hormones guide covers what genuinely, reliably moves testosterone (sleep, resistance training, body composition); most marketed T-boosters aren't on that list.
Detox teas and cleanses — the liver and kidneys already perform this function continuously; there's no credible mechanism by which a tea meaningfully assists a functioning detoxification system.
Most weight-loss supplements — the fundamentals covered in the Nutrition and Heart & Metabolic Health guides do the actual work; supplement categories promising an end-run around energy balance (calories in vs. calories out) overwhelmingly lack the evidence to back the claim.
The Simple Filter
Every supplement covered earlier in this guide passes a simple test: a specific dose, tested in specific controlled trials, with a specific, honestly stated evidence tier. Any supplement that can't clear that bar — undisclosed doses, no controlled trials, marketing claims well ahead of the evidence — is a reasonable one to skip, regardless of how it's marketed.
The honest summary
The supplements worth taking are a short, specific list — vitamin D3+K2, magnesium, omega-3, creatine, zinc, ashwagandha, L-theanine, choline — each with a real dose and a real evidence tier. Everything outside that list should be evaluated against the same simple filter: disclosed doses, controlled trials, and honest claims.