In stock
Is Penguin Peptides Legit
Is Penguin Peptides a legit peptide vendor? 9 independent lab tests across 2 products, with a limited lab record, and 200 verified customer reviews.
Written by the Peptide Vendor Reviews editorial team
Lab record: Limited
How we rate- 9 independent tests
- 6 of 6 lots filled to label
- Median purity 99.9%
- 2 of 2 products graded D or E
Some of Penguin Peptides's products graded D or E. The shops below tested A or B for the same peptides.
4.8
200 reviews · Excellent
Better-tested Retatrutide
Penguin 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 Penguin 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
Penguin Peptides: grade ETirzepatide
Penguin Peptides: grade DPenguin 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 Penguin Peptides' site.
- TirzepatideDPOOR
- Tests
- 6
- Passed
- 66.7%
- RetatrutideEBAD
- Tests
- 3
- Passed
- 33.3%
What the testing shows
Across 6 measured samples from Penguin Peptides, 0 came in more than 5% under the quantity on the label (0%). Another 1 measured more than 5% over. Purity across 7 readings ran from 98.9% to 99.95%, median 99.9%. Samples span Oct 2025 to Aug 2026.
- Under label
- 0/6
- Median purity
- 99.9%
- Latest sample
- Aug 2026
- Ships from
- United States
more than 5% short
98.9%–99.95% range
first tested Oct 2025
per vendor listing
Our read on Penguin Peptides
5 of Penguin Peptides' 9 graded samples passed (56%), and 100% of all samples were sent in by buyers rather than by the shop.
When a sample failed, the most common reason was the lab could not confirm it was the labelled peptide (2 times).
Against the 302 shops with at least five graded tests, Penguin Peptides' pass rate is at or above 19% of them, and it has more tests on record than 27% of them.
On Trustpilot, 200 customer reviews average 4.8 out of 5; the topic customers raise most is shipping and delivery, mentioned in 117 reviews, 97% of them positive.
When and how Penguin Peptides was tested
Samples per month. The darker part of each bar failed.
Oct '25
Jan '26
Mar '26
Jun '26
Jul '26
Aug '26
- Labs used
- Krause Analytical (6), BTLabs (3)
- Who sent the samples
- buyers 100%
- Batches covered
- 2 distinct batch numbers; 3 checked for endotoxins
Why Penguin Peptides' failed samples failed
The 4 most recent failed tests, with the lab's reason.
Tirzepatide · Aug 6, 2026
amount in the vial more than 35% off the label
Retatrutide · Jul 20, 2026
the lab could not confirm it was the labelled peptide
Retatrutide · Jul 10, 2026
the lab could not confirm it was the labelled peptide
Tirzepatide · Mar 4, 2026
purity under 99.5%
What Penguin Peptides' customers report
From 200 reviews on Trustpilot, the latest from Nov 27, 2025.
- Shipping and delivery117 mentions
97% of these were 4 or 5 stars
- Price and value45 mentions
98% of these were 4 or 5 stars
- Product quality44 mentions
100% of these were 4 or 5 stars
- Customer service36 mentions
94% of these were 4 or 5 stars
- Payment and refunds6 mentions
100% of these were 4 or 5 stars
- Orders not received4 mentions
100% of these were 4 or 5 stars
Typical praise · 5★
“Very professional, quick response, free shirt, discount codes, threw in a bac. water. Will use again.”
Typical complaint · 1★
“I was supposed to get a 10 mg bottle of something and I got a 5 mg bottle. I emailed and got no response on that.”
Most recent · 4★
“Shipping was super quick, packaging was well done, and when there was an issue with my address input Gary immediately recognized the issue, reached out, and resolved the…”
Catalog & prices
Every peptide and vial size Penguin Peptides currently sells. Prices refresh weekly.
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Showing 1–24 of 43 productsPrices refreshed weekly · Direct from Penguin Peptides
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Lab testing results
Independent results across 2 products.
9
Total lab tests
99.7%
Avg purity
99.9%
Best score
98.9%
Worst score
Individual lab tests
Tirzepatide10.0
Date
8/6/2026
Purity
99.9%
Quantity
20 mg → 40.6 mg
Lab
BTLabs
Vial
No label, Silver crimp, Green cap
Retatrutide
Date
7/20/2026
Purity
—
Quantity
—
Lab
Krause Analytical
Vial
No label / Silver crimp / Blue cap
Retatrutide
Date
7/10/2026
Purity
—
Quantity
—
Lab
BTLabs
Vial
No label / Silver crimp / Clear cap
Tirzepatide10.0
Date
6/16/2026
Purity
99.9%
Quantity
5 mg → 4.78 mg
Lab
Krause Analytical
Vial
White label / Silver crimp / Blue cap
Tirzepatide10.0
Date
6/1/2026
Purity
99.9%
Quantity
60 mg → 59.6 mg
Lab
Krause Analytical
Vial
White label / Copper crimp / Clear cap
| Product | Date | Score | Purity | Quantity | Lab | COA |
|---|---|---|---|---|---|---|
| TirzepatideNo label, Silver crimp, Green cap | 8/6/2026 | 10.0 | 99.9% | 20 mg → 40.6 mg | BTLabs | View |
| RetatrutideNo label / Silver crimp / Blue cap | 7/20/2026 | — | — | Krause Analytical | View | |
| RetatrutideNo label / Silver crimp / Clear cap | 7/10/2026 | — | — | BTLabs | View | |
| TirzepatideWhite label / Silver crimp / Blue cap | 6/16/2026 | 10.0 | 99.9% | 5 mg → 4.78 mg | Krause Analytical | View |
| TirzepatideWhite label / Copper crimp / Clear cap | 6/1/2026 | 10.0 | 99.9% | 60 mg → 59.6 mg | Krause Analytical | View |
Strong reviews, one product tested
Penguin Peptides has 213 customer reviews averaging 4.8 out of 5. Most mention low prices, welcome discounts and quick shipping, and several describe support fixing a missing item quickly.
Our lab data is narrow. We have five independent Tirzepatide tests from Krause Analytical, run between October 2025 and June 2026. Tirzepatide graded B, and none of the five vials came in more than 5% under label.
Buying from Penguin Peptides
We track 43 listings with current prices. The catalog includes Thymosin Alpha-1, BPC-157, Selank, Semax, MOTS-c, Kisspeptin, CJC-1295 and NAD+. HCG and Glutathione are its lowest prices per mg.
Tirzepatide is the only product with an independent record. For the rest of the catalog, ask for a certificate that matches your lot.
What to check before you pay
- The certificate names the lab and the lot - The lot on the vial matches it - Price per mg in the catalog above - The refund policy before you order
Track Penguin Peptides
Create a free account to save this vendor, get alerts for new lab tests, and watch price changes.
Penguin Peptides: common questions
Is Penguin Peptides legit?
We rate lab records, not businesses. Limited lab record: 9 independent tests, 6 of 6 lots filled to label, median purity 99.9%, 2 of 2 products graded D or E. Each result links to its original certificate in the table above.
What do Penguin Peptides reviews say?
We hold 200 customer reviews for Penguin Peptides, averaging 4.8 out of 5. Reviews describe service and delivery; the lab results describe what was in the vial.
Which Penguin Peptides peptides tested best?
We have graded 2 Penguin Peptides products. Tirzepatide and Retatrutide graded D or E.
Is there a Penguin Peptides coupon code?
We don't have a verified Penguin Peptides coupon code. A discount changes the price, not what is in the vial, so compare price per mg in the catalog above.
Where does Penguin Peptides ship from?
Public listings place Penguin Peptides's shipping origin in United States. Check the shop's own shipping page before ordering, as origin can change.
Ordering from Penguin Peptides?
Limited lab record: 9 independent tests, 6 of 6 lots filled to label, median purity 99.9%, 2 of 2 products graded D or E.
About Penguin Peptides
Penguin Peptides is a peptide vendor.