Research peptide purity: what 1,104 third-party HPLC results show
Published October 7, 2026 · Test dates December 7, 2023 to September 29, 2026 · 1,357 records
Across 1,104 third-party HPLC purity results for 63 research peptides, the median purity was 99.65%. 92.7% of results were at or above 99%; 81 (7.3%) came in under 99%, and 23 were under 98%.
The results are supplier test records: analyses run by third-party labs (Janoshik, Freedom Diagnostics and ILS Laboratories) and reported to Peptuvia by 11 of the vendors that sell through it, with test dates from December 2023 to September 2026. Peptuvia is a research peptide marketplace, and every compound here is sold for laboratory research use only.
Key findings
- Median purity was 99.65%; the middle half of results fell between 99.35% and 99.81%.
- 81 of 1,104 results (7.3%) were under 99%. 58 of those were between 98% and 99%; 8 were under 95%, and the lowest was 86.22% (ARA-290).
- Results under 99% cluster in a few compounds. Among compounds with 15 or more results, Semax (19%), KPV (17%) and Epithalon (17%) had the highest shares under 99%; 11 had none, including GHK-Cu (73 results) and SS-31 (58 results).
- The median vial measured 115% of its labeled amount; 7.4% measured under the label.
- 1,357 records from 11 vendors, run by 3 labs (Janoshik ran 97.0%), December 2023 to September 2026.
Distribution of HPLC purity results
Each bar is the share of the 1,104 purity results that fell in that range; bars under 99% are orange. The ranges are narrower near the top, where most results sit.
- < 95%: 0.7% of results (8)
- 95–97%: 0.3% of results (3)
- 97–98%: 1.1% of results (12)
- 98–99%: 5.3% of results (58)
- 99–99.5%: 28.8% of results (318)
- 99.5–99.8%: 35.1% of results (388)
- ≥ 99.8%: 28.7% of results (317)
| HPLC purity | Results | Share of results |
|---|---|---|
| < 95% | 8 | 0.7% |
| 95–97% | 3 | 0.3% |
| 97–98% | 12 | 1.1% |
| 98–99% | 58 | 5.3% |
| 99–99.5% | 318 | 28.8% |
| 99.5–99.8% | 388 | 35.1% |
| ≥ 99.8% | 317 | 28.7% |
Which peptides most often test under 99% purity
The share of results under 99% for each compound with at least 15 purity results. A compound with only a handful of results can swing on a single test, so compounds below that count are left off the chart and kept in the table below.
- Semax19% · 6 of 32
- KPV17% · 8 of 46
- Epithalon17% · 5 of 29
- TB-50016% · 9 of 56
- Pinealon11% · 2 of 18
- MOTS-c11% · 10 of 94
- Tesamorelin10% · 7 of 73
- DSIP9% · 3 of 34
- SNAP-88% · 2 of 25
- N-Acetyl Semax Amidate6% · 1 of 18
- ARA-2905% · 1 of 20
- Thymosin Alpha-13% · 1 of 33
- BPC-1573% · 2 of 71
- GHK-Cu0 of 73
- SS-310 of 58
- Melanotan-20 of 32
- PT-1410 of 30
- Ipamorelin0 of 29
- Selank0 of 28
- N-Acetyl Selank Amidate0 of 22
- Melanotan-10 of 21
- CJC-1295 (no DAC)0 of 16
- Cartalax0 of 15
- PE 22-280 of 15
Below the 15-result threshold, Oxytocin had 8 of 10 results under 99% (lowest 91.37%) and IGF-1 LR3 had 3 of 4 results under 99% (lowest 96.68%). Each is too few results for a reliable rate, and they are noted here because most of the results were under 99%.
Purity results by compound
| Compound | Results | Median purity | Under 99% | Lowest |
|---|---|---|---|---|
| Adamax | 12 | 99.63% | 0 | 99.14% |
| ARA-290 (Cibinetide) | 20 | 99.51% | 1 (5%) | 86.22% |
| BPC-157 | 71 | 99.65% | 2 (3%) | 98.69% |
| Bronchogen | 8 | 99.76% | 0 | 99.57% |
| Cardiogen | 5 | 99.44% | 0 | 99.10% |
| Cartalax | 15 | 99.78% | 0 | 99.42% |
| Chonluten | 5 | 99.79% | 0 | 99.57% |
| CJC-1295 (no DAC) | 16 | 99.41% | 0 | 99.04% |
| CJC-1295 (with DAC) | 10 | 99.17% | 1 (10%) | 98.88% |
| Cortagen | 5 | 99.83% | 0 | 99.49% |
| DSIP | 34 | 99.66% | 3 (9%) | 98.44% |
| Epithalon (Epitalon) | 29 | 99.40% | 5 (17%) | 91.17% |
| FOXO4-DRI | 9 | 99.63% | 1 (11%) | 98.40% |
| GHK-Cu (Copper Peptide) | 73 | 99.77% | 0 | 99.23% |
| GHRP-2 | 5 | 99.66% | 0 | 99.22% |
| GHRP-6 | 6 | 99.52% | 0 | 99.19% |
| Glutathione | 7 | 99.86% | 0 | 99.07% |
| Ipamorelin | 29 | 99.75% | 0 | 99.04% |
| Kisspeptin-10 | 14 | 99.72% | 0 | 99.30% |
| KPV | 46 | 99.49% | 8 (17%) | 97.71% |
| LL-37 | 6 | 99.48% | 0 | 99.15% |
| Melanotan-1 | 21 | 99.80% | 0 | 99.22% |
| Melanotan-2 | 32 | 99.79% | 0 | 99.16% |
| MOTS-c | 94 | 99.29% | 10 (11%) | 98.29% |
| N-Acetyl Selank Amidate | 22 | 99.63% | 0 | 99.36% |
| N-Acetyl Semax Amidate | 18 | 99.66% | 1 (6%) | 98.88% |
| Ovagen | 7 | 99.77% | 1 (14%) | 96.69% |
| Oxytocin | 10 | 97.13% | 8 (80%) | 91.37% |
| P21 | 9 | 99.40% | 1 (11%) | 98.27% |
| PE 22-28 | 15 | 99.69% | 0 | 99.41% |
| Pinealon | 18 | 99.54% | 2 (11%) | 98.49% |
| PNC-27 | 6 | 99.26% | 1 (17%) | 98.94% |
| Prostamax | 8 | 99.83% | 0 | 99.00% |
| PT-141 (Bremelanotide) | 30 | 99.82% | 0 | 99.02% |
| Selank | 28 | 99.72% | 0 | 99.10% |
| Semax | 32 | 99.34% | 6 (19%) | 98.28% |
| Sermorelin | 11 | 99.41% | 2 (18%) | 98.56% |
| SNAP-8 | 25 | 99.80% | 2 (8%) | 93.97% |
| SS-31 (Elamipretide) | 58 | 99.81% | 0 | 99.34% |
| TB-500 (Thymosin Beta-4) | 56 | 99.49% | 9 (16%) | 97.49% |
| Tesamorelin | 73 | 99.38% | 7 (10%) | 98.08% |
| Testagen | 5 | 99.73% | 0 | 99.58% |
| Thymosin Alpha-1 | 33 | 99.68% | 1 (3%) | 98.83% |
| Vesugen | 7 | 99.86% | 0 | 99.76% |
| Vilon | 5 | 99.53% | 0 | 99.17% |
| VIP | 10 | 99.51% | 1 (10%) | 97.51% |
Net peptide content compared with the label
1,153 results report the net peptide content the lab measured alongside the vial's labeled amount. The median vial measured 115% of its label, and the middle half measured between 108% and 122%. 85 results (7.4%) measured under the label and 12 under 90% of it; 30.4% measured 120% or more.
A label states a nominal amount, and filling above it is common. The net content on a certificate is what the lab measured in the vial it tested.
| Labeled strength | Results | Median content (% of label) | Under label |
|---|---|---|---|
| Up to 5 mg | 82 | 114% | 11.0% |
| 6–10 mg | 628 | 116% | 4.8% |
| 11–20 mg | 194 | 114% | 4.1% |
| 21–50 mg | 134 | 115% | 11.9% |
| Over 50 mg | 115 | 110% | 19.1% |
Where the data comes from
Source: the supplier test records published on Peptuvia's lab results page, where each record is listed with its batch code, lab and test date. These are results vendors reported to Peptuvia; the certificates Peptuvia hosts are a separate set and are not part of this analysis.
Scope: 1,357 records across 68 compounds, of which 1,104 carry an HPLC purity figure. The rest were content or mass assays, which is how most blends are tested. Not every compound Peptuvia lists is included.
Purity is the figure the lab reported for the sample. Net content is compared with the labeled strength on the same record; 2 records are left out of the content figures because the labeled strength recorded for them matches no plausible fill. Medians and quartiles are nearest-rank, and shares are rounded to one decimal place.
Limitations
This is not a random sample. The records are the results vendors reported to Peptuvia, so they show what was tested and reported, not every production run.
One vendor accounts for 67% of the records, so its results weigh heavily on the pooled figures. Across the 6 vendors with 15 or more purity results, median purity ranged from 99.27% to 99.79%, and the share under 99% from 0.0% to 19.0%.
HPLC purity is the share of the detected components in a sample that is the target peptide. On its own it does not confirm identity (mass spectrometry does) and it does not measure net content, endotoxin or heavy metals; those are separate tests.
A certificate covers the lot it names and nothing else. Vendors ship thousands of kits and restock continuously, so there's no guarantee your order will come from the tested lot. We don't test every batch. We publish every lab result we receive, pass or fail.
Related guides
Frequently asked questions
What purity do third-party labs report for research peptides?
In 1,104 third-party HPLC results for 63 research peptides reported to Peptuvia, the median purity was 99.65%, with the middle half between 99.35% and 99.81%. 7.3% of results were under 99% and 2.1% were under 98%.
Which research peptides most often test under 99% purity?
Among compounds with at least 15 results, the highest shares under 99% were Semax (6 of 32), KPV (8 of 46), Epithalon (5 of 29) and TB-500 (9 of 56). 11 compounds with 15 or more results had no result under 99%, including GHK-Cu, SS-31 and Melanotan-2.
Does a certificate of analysis cover every vial of a peptide?
No. A certificate covers the lot it names and nothing else. Vendors ship thousands of kits and restock continuously, so there's no guarantee your order will come from the tested lot. We don't test every batch.
Do research peptide vials contain the amount on the label?
In 1,153 results that report both figures, the median vial measured 115% of its labeled amount, and 7.4% measured under the label. The net content on a certificate is what the lab measured in the vial it tested.
Where does this purity data come from?
From the supplier test records Peptuvia publishes: results from third-party labs (Janoshik, Freedom Diagnostics and ILS Laboratories) that 11 vendors reported to Peptuvia. Each record is listed with its batch code, lab and test date on Peptuvia's lab results page.
For Research Use Only. All products are sold as research chemicals for in-vitro laboratory study. Not for human consumption, medical, veterinary, or household use.