Data-first notes on supplements by Nerd Protocols, a clinical and sports dietitian based in the EU. What the trials measured, what the community ratings show, and where the two disagree.
500 mg of magnesium glycinate is not 500 mg of magnesium. Here is how to work out the elemental dose, what absorption studies found for oxide, and where the 'brain magnesium' claim comes from.
Melatonin trials show modest effects on how fast you fall asleep and bigger effects on when your body clock runs. Dose matters less than timing, and labels are unreliable.
A systematic review of 32 RCTs found that only 9 showed a significant rise in testosterone, and only 6 had a low risk of bias. Meanwhile one week of short sleep cut daytime testosterone by 10 to 15%.
A meta-analysis of 24 studies put numbers on caffeine's sleep cost and on the gap you need before bed. For a typical pre-workout serving, the answer is over 13 hours.
Most supplements stay in a routine for years without anyone checking whether they work. A simple framework, using trial lengths and measurable markers, turns a habit into a test.
