Strength & muscle

Also in the library: Ingredients · Goals · Evidence · Learn

Athlete holding a kettlebell in a quiet gym

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

How to read a grade

  1. Creatine monohydrate 3–5 g daily, any time; skip loading phases — they only speed up saturation

    Lanhers C, 2017 · Kreider RB, 2017

  2. Caffeine 3–6 mg/kg, 30–60 minutes before training; respect the 8–10 hour bedtime cutoff

    Grgic J, 2018

  3. Citrulline malate 8 g citrulline malate 45–60 minutes before sessions; session-level aid, not a foundation

    Rhim HC, 2020 · Pérez-Guisado J, 2010

  4. Collagen peptides 15 g daily alongside resistance training; counts toward connective tissue, not protein target

    Zdzieblik D, 2015

  5. Vitamin D3 1000–2000 IU daily with food; muscle benefit shows mainly when starting deficient

    Beaudart C, 2014

Grades are per goal–ingredient pairing, hand-assigned from the evidence records linked below each name. Browse all records. Ingredients without a monograph link have a page 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.

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