Sigma Peptides reviews
Sigma Peptides reviews: 3 independent lab tests across 1 product, with a limited lab record.
Written by the Peptide Vendor Reviews editorial team
Is Sigma Peptides legit? Lab record: Limited
How we rate- 3 independent tests
- 2 of 3 lots filled to label
- Median purity 99.01%
- 1 of 1 product graded D or E
Some of Sigma Peptides's products graded D or E. The shops below tested A or B for the same peptides.
Better-tested Retatrutide
Sigma Peptides graded E. Paradigm Peptide's Retatrutide graded A across 8 tests, $10.00 / mg.
Buy from Paradigm PeptideAll better-tested optionsPeptide Vendor Reviews independently tests products and verifies reviews. Public methodology, no pay-to-rank.
Better-tested options
Where Sigma Peptides graded D or E, these shops' samples of the same peptide graded A or B. Ordered by grade, then price per mg. Partner status never changes the order.
Retatrutide
Sigma Peptides: grade ESigma Peptides products we've tested
Best-graded first. Grades come from the share of each product's samples that passed purity and quantity checks. Buy links open Sigma Peptides' site.
- RetatrutideEBAD
- Tests
- 3
- Passed
- 33.3%
What the testing shows
Across 3 measured samples from Sigma Peptides, 1 came in more than 5% under the quantity on the label (33%). Purity across 3 readings ran from 98.84% to 99.9%, median 99.01%. Samples span Nov 2025 to Mar 2026.
- Under label
- 1/3
- Median purity
- 99.01%
- Latest sample
- Mar 2026
- Ships from
- United States
more than 5% short
98.84%–99.9% range
first tested Nov 2025
per vendor listing
Our read on Sigma Peptides
1 of Sigma Peptides' 3 graded samples passed (33%), and 100% of all samples were sent in by buyers rather than by the shop.
When a sample failed, the most common reason was purity under 99.5% (2 times).
When and how Sigma Peptides was tested
Samples per month. The darker part of each bar failed.
- Labs used
- Krause Analytical (3)
- Who sent the samples
- buyers 100%
- Batches covered
- 1 distinct batch numbers
Why Sigma Peptides' failed samples failed
The 2 most recent failed tests, with the lab's reason.
Retatrutide · Mar 3, 2026
purity under 99.5%
Retatrutide · Nov 17, 2025
purity under 99.5%
Lab testing results
Independent results across 1 product.
Individual lab tests
Date
3/3/2026
Purity
99.01%
Quantity
5 mg → 5 mg
Lab
Krause Analytical
Vial
White Label / Silver Crimp / Blue Cap
Date
2/20/2026
Purity
99.9%
Quantity
5 mg → 4.71 mg
Lab
Krause Analytical
Vial
No Label / Silver Crimp / Blue Cap
Date
11/17/2025
Purity
98.84%
Quantity
10 mg → 10 mg
Lab
Krause Analytical
Vial
No Label / Silver Crimp / Yellow Cap
| Product | Date | Score | Purity | Quantity | Lab | COA |
|---|---|---|---|---|---|---|
| RetatrutideWhite Label / Silver Crimp / Blue Cap | 3/3/2026 | 9.9 | 99.01% | 5 mg → 5 mg | Krause Analytical | View |
| RetatrutideNo Label / Silver Crimp / Blue Cap | 2/20/2026 | 10.0 | 99.9% | 5 mg → 4.71 mg | Krause Analytical | View |
| RetatrutideNo Label / Silver Crimp / Yellow Cap | 11/17/2025 | 9.9 | 98.84% | 10 mg → 10 mg | Krause Analytical | View |
Which Sigma Peptides products tested best
Retatrutide graded D or E: a large share of its samples missed purity or quantity thresholds.
Buying from Sigma Peptides
We don't track Sigma Peptides' prices yet. Shipping, payment and refund terms are on their site.
The official store is sigmapeptides.com. Check the address before you pay.
What to check before you pay
- The lot number on the vial matches the certificate
- The certificate names the lab and the test date
- Fill versus label, not purity alone
- A refund policy in writing
Track Sigma Peptides
Create a free account to save this vendor, get alerts for new lab tests, and watch price changes.
Sigma Peptides: common questions
Is Sigma Peptides legit?
We rate lab records, not businesses. Limited lab record: 3 independent tests, 2 of 3 lots filled to label, median purity 99.01%, 1 of 1 product graded D or E. Each result links to its original certificate in the table above.
What do Sigma Peptides reviews say?
We don't hold scored customer reviews for Sigma Peptides yet. The independent lab results on this page are the evidence we have.
Which Sigma Peptides peptides tested best?
We have graded 1 Sigma Peptides product. Retatrutide graded D or E.
Is there a Sigma Peptides coupon code?
We don't have a verified Sigma Peptides coupon code. A discount changes the price, not what is in the vial.
Where does Sigma Peptides ship from?
Public listings place Sigma Peptides's shipping origin in United States. Check the shop's own shipping page before ordering, as origin can change.
Ordering from Sigma Peptides?
Limited lab record: 3 independent tests, 2 of 3 lots filled to label, median purity 99.01%, 1 of 1 product graded D or E.