What the science says
For 779 substances we searched PubMed for meta-analyses, systematic reviews and randomized controlled trials in humans. The grade shows how deep the research base is; each substance page shows what the reviews actually concluded.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans.
At least one meta-analysis, or 5+ randomized controlled trials.
1–4 randomized controlled trials, no meta-analysis yet.
No randomized controlled trials in humans found on PubMed.
Users ahead of science
Popular and well-rated by users, but little clinical research so far.
Science ahead of users
Heavily studied, but users report modest results.
Grade B: moderate research base
| Substance | Grade | Meta-analyses | RCTs | User score |
|---|---|---|---|---|
| Methylated B VitaminsSupplement | B | 46 | 0 | 26 |
| CBNSupplement | B | 23 | 8 | 29 |
| RetatrutidePeptide | B | 22 | 6 | 73 |
| KratomSubstance | B | 18 | 5 | 50 |
| Methylated B ComplexSupplement | B | 17 | 0 | 29 |
| Psilocybin MicrodoseSubstance | B | 13 | 0 | 21 |
| FisetinSupplement | B | 12 | 7 | 45 |
| LSD MicrodoseSubstance | B | 12 | 0 | 37 |
| PassionflowerSupplement | B | 10 | 8 | 55 |
| Chia SeedsSupplement | B | 10 | 8 | 33 |
| KelpSupplement | B | 10 | 5 | 23 |
| ReishiSupplement | B | 9 | 3 | 38 |
| DmaaSubstance | B | 9 | 8 | 15 |
| KannaSupplement | B | 8 | 0 | 39 |
| Tongkat AliSupplement | B | 7 | 6 | 43 |
| DihydromyricetinSupplement | B | 7 | 2 | 26 |
| Uridine MonophosphateSupplement | B | 7 | 7 | 25 |
| PolygalaSupplement | B | 6 | 3 | 47 |
| Apple Cider VinegarSupplement | B | 6 | 5 | 34 |
| SkullcapSupplement | B | 5 | 3 | 49 |
| VyvanseMedication | B | 5 | 3 | 36 |
| Polygala TenuifoliaSupplement | B | 5 | 3 | 15 |
| Lion's ManeSupplement | B | 4 | 5 | 46 |
| CistancheSupplement | B | 4 | 6 | 31 |
| Holy BasilSupplement | B | 4 | 4 | 31 |
| Coconut WaterSupplement | B | 4 | 9 | 26 |
| MucunaSupplement | B | 4 | 9 | 15 |
| ZMASupplement | B | 3 | 1 | 55 |
| SAM-ESupplement | B | 3 | 1 | 54 |
| PhenibutSubstance | B | 3 | 1 | 49 |
| Korean GinsengSupplement | B | 3 | 6 | 32 |
| Horny Goat WeedSupplement | B | 3 | 0 | 30 |
| ClomidMedication | B | 3 | 5 | 28 |
| Maca RootSupplement | B | 3 | 1 | 28 |
| YohimbeSupplement | B | 3 | 3 | 26 |
| Reishi MushroomSupplement | B | 3 | 1 | 24 |
| DamianaSupplement | B | 3 | 6 | 22 |
| SarmsSARM | B | 3 | 2 | 15 |
| CialisMedication | B | 2 | 10 | 57 |
| Black Seed OilSupplement | B | 2 | 9 | 56 |
| Valerian RootSupplement | B | 2 | 8 | 54 |
| WellbutrinMedication | B | 2 | 3 | 54 |
| AgmatineSupplement | B | 2 | 6 | 52 |
| Gotu KolaSupplement | B | 2 | 4 | 49 |
| Methyl B12Supplement | B | 2 | 2 | 49 |
| EmoxypineSupplement | B | 2 | 2 | 46 |
| EnclomipheneMedication | B | 2 | 3 | 33 |
| ConcertaMedication | B | 2 | 30 | 31 |
| ParaxanthineSupplement | B | 2 | 45 | 29 |
| Magnolia BarkSupplement | B | 2 | 6 | 28 |
| Algae OilSupplement | B | 2 | 4 | 27 |
| Protein PowderSupplement | B | 2 | 50 | 26 |
| NattokinaseSupplement | B | 2 | 8 | 23 |
| SerrapeptaseSupplement | B | 2 | 5 | 22 |
| PterostilbeneSupplement | B | 2 | 7 | 19 |
| Testosterone CypionateMedication | B | 1 | 21 | 59 |
| LGD-4033SARM | B | 1 | 1 | 57 |
| AniracetamSupplement | B | 1 | 9 | 50 |
| XanaxMedication | B | 1 | 5 | 50 |
| DMAESupplement | B | 1 | 4 | 48 |
| Alpha-GpcSupplement | B | 1 | 13 | 47 |
| BromantaneSubstance | B | 1 | 0 | 46 |
| Saffron ExtractSupplement | B | 1 | 21 | 46 |
| NefiracetamSupplement | B | 1 | 3 | 45 |
| Chamomile TeaSupplement | B | 1 | 4 | 40 |
| FasoracetamSupplement | B | 1 | 0 | 36 |
| LexaproMedication | B | 1 | 4 | 36 |
| NAC (n-Acetylcysteine)Supplement | B | 1 | 0 | 36 |
| Mucuna PruriensSupplement | B | 1 | 6 | 34 |
| Vitamin B6 P5PSupplement | B | 1 | 0 | 33 |
| Magnesium OrotateSupplement | B | 1 | 8 | 32 |
| Melanotan IiPeptide | B | 1 | 1 | 32 |
| ShilajitSupplement | B | 1 | 7 | 31 |
| KpvPeptide | B | 1 | 0 | 29 |
| BenadrylMedication | B | 1 | 13 | 28 |
| DihexaPeptide | B | 1 | 0 | 28 |
| TesofensineSubstance | B | 1 | 11 | 28 |
| EtifoxineMedication | B | 1 | 12 | 27 |
| Choline BitartrateSupplement | B | 1 | 18 | 24 |
| Liposomal Vitamin CSupplement | B | 1 | 4 | 24 |
| Pre-WorkoutSupplement | B | 1 | 38 | 24 |
| OleamideSupplement | B | 1 | 5 | 22 |
| SauerkrautSupplement | B | 1 | 5 | 22 |
| EffexorMedication | B | 1 | 6 | 19 |
| ARA-290Peptide | B | 1 | 2 | 18 |
| P5PSupplement | B | 1 | 3 | 15 |
| DsipPeptide | B | 0 | 5 | 54 |
| MK-677SARM | B | 0 | 15 | 51 |
| Collagen PowderSupplement | B | 0 | 5 | 48 |
| StratteraMedication | B | 0 | 10 | 32 |
| PQQSupplement | B | 0 | 8 | 31 |
| ZoloftMedication | B | 0 | 9 | 31 |
| DexedrineMedication | B | 0 | 5 | 28 |
| TheacrineSupplement | B | 0 | 12 | 28 |
| Adderall XrMedication | B | 0 | 15 | 25 |
| GHRP-2Peptide | B | 0 | 41 | 23 |
Counts come from PubMed searches on the substance name in titles and abstracts; trial counts are limited to human studies. A grade reflects how much research exists, not whether the results were positive. Method details