Strength & muscle
Muscle grows in response to progressive resistance training and enough protein; supplements sit on top of that, never in place of it. The mechanisms that respond to supplementation are specific: phosphocreatine stores for repeated high-power efforts, arousal and perceived effort for training quality, and substrate for the connective tissue that carries the load.
Expect small, compounding effects — extra reps late in a session, a little more lean mass over a training block — that add up across months of consistency. The list below leads with creatine because that is where the trial record runs deepest; everything after it earns a smaller, more situational place.
Ranked by evidence
- Creatine monohydrate 3–5 g daily, any time; skip loading phases — they only speed up saturation
- Caffeine 3–6 mg/kg, 30–60 minutes before training; respect the 8–10 hour bedtime cutoff
- Citrulline malate 8 g citrulline malate 45–60 minutes before sessions; session-level aid, not a foundation
- Collagen peptides 15 g daily alongside resistance training; counts toward connective tissue, not protein target
- Vitamin D3 1000–2000 IU daily with food; muscle benefit shows mainly when starting deficient
Grades are per goal–ingredient pairing, hand-assigned from the evidence records linked on each monograph. Ingredients without a link have a monograph on the way.
What does not work (yet)
- Creatine HCl at matched doses. More soluble and marketed hard, but far less studied — no shown advantage over plain monohydrate at the same dose.
- Zinc for extra muscle gain. Raised testosterone only where low zinc status was corrected. Surplus zinc on an adequate diet has shown no strength effect.
- BPC-157. Rodent data only — no published human efficacy trials, and it sits outside the dietary-supplement category entirely. Read the editorial
The list above is the general case. Your medications, current stack, budget, and other goals change it — sometimes a lot.