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. One is settled, one is real and over-prescribed, and the rest of the aisle does not survive the trials.
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, small, and conditional: it does nothing measurable without the training to go with it. | established | 0.66 lb of extra fat-free mass, across 49 trials and 1,863 people |
| What | Verdict | What we measured |
| Creatine, for women specifically Studied mostly in postmenopausal women, where it added lean mass and considerably more leg strength. | supported | 0.8 lb of lean mass, over a median of nine months |
| Collagen Not a muscle supplement. Sold as one often enough to belong here. | supported | 95% of the pooled participants were women |
| What | Verdict | What we measured |
| Ashwagandha Cortisol moves. Whether you feel any better is a separate question, and the study that asked both got two different answers. | preliminary | 0.40 p-value for perceived stress — the outcome it is sold on |
| Colostrum One trial in thirteen moved body fat, using sixty grams a day. | preliminary | 60 g a day, in the one trial that moved body fat — by 0.4% |
| What | Verdict | What we measured |
| Fat burners | unsupported | 21 trials. the effect crossed zero |
| NAD+ and NMN | unsupported | 80 of 113 studies in the review were in rodents |
| Sea moss | unsupported | 4 toxic heavy metals the NIH record names in sea moss |
| Methylene blue | unsupported | 1 FDA-approved use, and it is a poisoning antidote |
| Krill oil, against fish oil | unsupported | 12 men in the absorption study the whole category cites |
| Berberine | unsupported | 17x more weight lost on the drug than on the supplement named after it |
| Creatine for fat loss | unsupported | 1.9 lb added to your scale mid-diet — and almost none of it is fat |
Established means several independent lines of evidence agree. Supported means good evidence with a caveat worth knowing. Preliminary means real trials exist and are not yet good enough to tell you what the thing does. Unsupported means we looked and the claim was not there.
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.