Supplements With the Weakest Evidence
Of 274 dietary supplements we rated, only 59 reach strong evidence and 100 (36%) rest on emerging or insufficient research. 12 of the weakest, including widely sold research peptides like BPC-157 and TB-500, are backed by zero human studies. This report maps where the science is thinnest, using NutriStack's own evidence tiers.
Report snapshot
- Supplements rated
- 274
- On weak evidence
- 36%
- Zero human studies
- 12
- Reach strong evidence
- 22%
Medical disclaimer
Informational only. This report is not medical advice and is not a substitute for a clinician or pharmacist. Never start, stop, or change a supplement or medication based on this page. Ask a qualified clinician or pharmacist about your own medications, health conditions, doses, and timing. A weak evidence tier is not a safety rating, and the absence of a supplement from this report does not mean it is safe or effective.
Key findings
What the snapshot shows.
These findings use only the locked statistics in the report data file.
Summary
- We rated 274 dietary supplements on a four-tier evidence scale. Only 59 (22%) reach the strong tier; 100 (36%) rest on emerging or insufficient evidence.
- 12 of the insufficient-rated supplements cite zero human studies of any kind (16 across both weak tiers). Most are research peptides such as BPC-157, TB-500, and AOD-9604 that are sold widely but are not approved for human use; their support rests on animal, cell, or mechanistic data.
- 33 supplements are rated insufficient: the human research is too thin, too early, or too conflicting to support confident conclusions about their benefits.
- Peptides are the weakest category. 22 of 25 (88%) supplements filed under peptides sit in the two weakest tiers, and several more research peptides are classified under Other, so the real share is higher.
- At the other end, vitamins are the best-evidenced category: only 1 of 22 (5%) fall in the weakest tiers.
- This report surfaces NutriStack's own evidence tiers. A weak rating flags where the science is unsettled. It is not a verdict that a supplement does not work.
By category
Where the evidence is weakest.
The share of each category's supplements that sit in the two weakest tiers, emerging or insufficient. Categories with fewer than five rated supplements are omitted.
Weak-evidence share by category
| Category | Supplements rated | On weak evidence |
|---|---|---|
| Peptide | 25 | 88% |
| Antioxidant | 21 | 52% |
| Other | 64 | 42% |
| Adaptogen | 8 | 38% |
| Herb | 61 | 36% |
| Mineral | 24 | 25% |
| Omega/Fatty Acid | 10 | 20% |
| Amino Acid | 28 | 14% |
| Probiotic | 7 | 14% |
| Vitamin | 22 | 5% |
Several research peptides (for example BPC-157, TB-500, and MK-677) are filed under Other rather than Peptide, so the true peptide share is higher.
Insufficient tier
The supplements rated insufficient.
Sorted with the least-studied first. Each row links to the full profile, including benefits tracked, mechanism, and the cited sources behind the tier.
Rated insufficient
| Supplement | Category | Indexed sources | Human studies |
|---|---|---|---|
| BPC-157 | Other | 2 | 0 |
| TB-500 | Other | 2 | 0 |
| AOD-9604 | Other | 3 | 0 |
| Dihexa | Peptide | 3 | 0 |
| GHRP-6 | Peptide | 3 | 0 |
| Hexarelin | Peptide | 3 | 0 |
| Humanin | Peptide | 3 | 0 |
| IGF-1 LR3 (Long R3 IGF-1) | Peptide | 3 | 0 |
| KPV | Peptide | 3 | 0 |
| Marshmallow Root | Herb | 3 | 0 |
| Noopept | Other | 3 | 0 |
| Pentadeca Arginate (PDA) | Peptide | 3 | 0 |
| Agmatine Sulfate | Amino Acid | 3 | 1 |
| Epitalon | Peptide | 3 | 1 |
| GHRP-2 | Peptide | 3 | 1 |
| HGH Fragment 176-191 | Peptide | 3 | 1 |
| Ipamorelin | Other | 3 | 1 |
| MOTS-c | Peptide | 3 | 1 |
| Selank | Peptide | 3 | 1 |
| Slippery Elm | Herb | 3 | 1 |
| Thymalin | Peptide | 3 | 1 |
| Vinpocetine | Other | 3 | 1 |
| Wild Yam | Herb | 3 | 1 |
| CJC-1295 | Other | 3 | 2 |
| Dong Quai | Herb | 3 | 2 |
| DSIP (Delta Sleep-Inducing Peptide) | Peptide | 3 | 2 |
| MK-677 (Ibutamoren) | Other | 3 | 2 |
| Semax | Peptide | 3 | 2 |
| VIP (Vasoactive Intestinal Peptide) | Peptide | 3 | 2 |
| Melanotan II | Other | 4 | 2 |
| Bee Pollen | Other | 20 | 5 |
| Lithium Orotate | Mineral | 14 | 6 |
| Saw Palmetto | Herb | 19 | 14 |
A high source count next to an insufficient tier means studied but unconvincing; a count near zero means barely studied in humans.
What this means
What a weak rating means, and what it does not.
The most important section to read before sharing a number from this report.
Reading the tiers
A weak rating is a statement about the evidence, not a verdict on the supplement. Emerging and insufficient mean the human research is small, early, indirect, or mixed. They do not mean a supplement has been proven ineffective or unsafe.
Two different situations both earn a weak rating. Some supplements are under-studied: research peptides like BPC-157 and TB-500 are sold widely as research chemicals, several are not approved for human use, and they carry almost no human trials. Others are well-studied but unconvincing: a supplement can carry many trials and still rate insufficient when those trials are null or conflicting. The "indexed sources" and "human studies" columns let you tell the two apart, and the table is sorted with the least-studied first.
Ratings move as science matures. A supplement in the emerging tier today can climb to moderate or strong as good human trials accumulate. The reverse can happen too, when larger trials fail to replicate an early signal.
A strong rating is about the weight of evidence, not a personal recommendation. Whether any supplement is right for you depends on your health, medications, and goals. Discuss that with a clinician or pharmacist.
The other side
What strong evidence looks like.
For balance: the best-evidenced supplements in the library show what a mature research base looks like.
Strongest-evidence examples
Probiotics, Vitamin D3, Fish Oil, Inositol, Iron, Potassium, Psyllium Husk, SAMe.
Evidence tiers
How the four tiers are defined.
Supplements are rated on the strength and directness of the supporting literature.
Evidence tiers
- Strong
- 59
- Moderate
- 115
- Emerging
- 67
- Insufficient
- 33
Strong means multiple high-quality RCTs or meta-analyses point the same way. Moderate means consistent evidence from quality studies, with open questions. Emerging means promising early signals, not yet confirmed at scale. Insufficient means sparse, conflicting, or mostly preclinical evidence: not enough to draw a confident conclusion. These are the same tiers shown on every supplement profile in the library.
Methodology
How this report was built.
The report is a database snapshot, not a clinical decision tool.
Scope and definitions
Data source. NutriStack supplement database. Each supplement carries an evidence tier assigned from its cited literature (PubMed/MEDLINE, Cochrane, NIH ODS, EFSA, and similar references).
Weak-evidence definition. "Weak evidence" means the two lowest tiers, emerging and insufficient. The figures count supplements by their overall evidence tier, not by individual claims.
Indexed sources and human studies. Both counts use the same merged reference set shown on each supplement profile (the database's cited sources plus matching indexed studies, de-duplicated). A source counts as a human study when its type is a meta-analysis or systematic review, a randomized controlled or clinical trial, or an observational human study (cohort, case-control, cross-sectional, or case report). Animal, cell, in-vitro, mechanistic, and narrative-review sources are not counted as human studies.
Not a legality or safety statement. The database includes research peptides and other compounds sold or used as supplements, several of which are not approved as dietary supplements or as drugs for human use. An evidence tier reflects the strength of research only; it is not a statement about a compound's legality or safety.
Scope. 274 dietary supplements with an assigned evidence tier. Recreational and harm-reduction substance profiles (Alcohol, Cannabis (THC-Dominant), Cocaine, Ketamine, MDMA, Nicotine, Psilocybin) were excluded, because they are not dietary supplements.
Limitation. Source counts reflect the curated reference set in the database, not an exhaustive systematic search. For the research peptides above, the absence of human studies is genuine; for well-studied supplements, a low count reflects how much we surface, not all literature that exists.
Data and citation. The full rated table is published as a downloadable dataset: weakest-evidence-supplements/data.csv. Cite as: NutriStack, "Supplements With the Weakest Evidence," June 8, 2026, nutristackapp.com.
Last updated. June 8, 2026. This is a snapshot and will change as the database expands and as new evidence is reviewed.
Medical disclaimer, repeated
Informational only. This report is not medical advice and is not a substitute for a clinician or pharmacist. Never start, stop, or change a supplement or medication based on this page. Ask a qualified clinician or pharmacist about your own medications, health conditions, doses, and timing. A weak evidence tier is not a safety rating, and the absence of a supplement from this report does not mean it is safe or effective.
Next step
See the evidence behind any supplement.
Open any profile to read its tier, the cited studies, and what the research actually shows. Then discuss changes with a clinician or pharmacist.