Best Supplements for Muscle Growth: Ranked by Evidence, Not by Sales
An index of the muscle supplements we have actually checked, ranked by the confidence rating we gave each one. No products named, nothing for sale. Creatine and protein hold up for building muscle; the rest are unsettled, rated for something else, or did not hold up.
In 2003 two researchers took every supplement claimed to build muscle, set a minimum standard of evidence, and counted how many cleared it. They examined 250. Two produced a significant effect. [the full verdict]
We have since checked 13 of them ourselves, one at a time, reading the trials rather than the labels. This page is the running scoreboard.
Nothing here is for sale and nothing links to a shop. Every row goes to the verdict it came from, so you can check the working.
| What | Verdict | What we measured |
| Creatine The most-tested supplement in the category, and one of only two that survived a screen of 250. | established | 2 of 250 supplements that beat resistance training alone. Creatine was one. |
| Protein Real and small for people who lift: about two-thirds of a pound of extra lean mass. Without lifting or dieting, no clear gain has been shown. | established | 0.66 lb of extra fat-free mass in people who lift: 26 comparisons, 1,089 people, in a 2018 review |
| What | Verdict | What we measured |
| Creatine, for women specifically Studied mostly in women past menopause: under a pound of lean mass on a scan that counts water, with three of the five pooled trials finding none, and no leg-press or squat gain over lifting alone. | preliminary | 3 of 5 trials behind the lean-mass figure found no gain in lean mass |
| Collagen Checked here for skin, where most of the trials have a company in them, and for weight gain, which the trials did not bear out. Nothing on this site rates it for muscle. | preliminary | 95% of the pooled participants were women |
| Ashwagandha Cortisol moves and testosterone rose in men. Whether anyone feels better is contested, and most trials had a company’s money, product or staff. | preliminary | 0.40 p-value for perceived stress in one of four reviews; three found a drop |
| Krill oil, against fish oil | preliminary | 4 of the 64 pooled trials put krill oil and fish oil in the same trial |
| What | Verdict | What we measured |
| Colostrum Rated Preliminary, for a gut claim. Eight controlled trials measured body fat against another protein powder, and colostrum came out ahead in none. | preliminary | 5 small trials in healthy volunteers behind the gut result; in one of them the marker rose on colostrum |
| What | Verdict | What we measured |
| Fat burners | unsupported | 21 studies. not one without diet or exercise |
| NAD+ and NMN | unsupported | 80 of 113 studies in the review were in rodents |
| Sea moss | unsupported | 57 adults in a placebo trial that found no edge |
| Methylene blue | unsupported | 26 healthy adults given one dose by mouth |
| Berberine | unsupported | 14x more weight lost on the drug than on the supplement named after it, each against people not taking it |
| Creatine for fat loss | unsupported | 1.9 lb added to your scale mid-diet — and almost none of it is fat |
Established means multiple good studies agree: treat it as settled. Supported means the evidence is consistent, with known limits. Preliminary means the evidence is early, small, conflicting or from animals only: not enough to act on alone. Unsupported means we looked and the evidence does not back the claim: either it was tested and did not hold up, or nobody has tested it and nothing that was tested supports it.
A page like this is normally a shopping list. This one is a scoreboard — and the most useful column is the last, because a supplement that works by two thirds of a pound over nine months is not the same product as the one on the label.
The same corpus, asked two other ways: for men and for women, where the question becomes who was actually in the trials, and for gut health, where one item is settled and it is fiber. And for recovery, where the best-evidenced thing on the list is not a supplement at all, and for weight loss, where nothing reaches Established for weight loss, and for sleep, where exactly one entry is Supported and what it buys is measured in minutes, and for sweeteners, where every claim is a worry and the ratings run backwards.
The four ratings are the same ones used on every verdict here, and we wrote down how we read a study so you can see what earns each one.