Reviewed by Jack Ryan, co-founder & editorial lead · Updated
COA practices 40%8/10
Reputation 20%7.5/10
Transparency 20%8.5/10
Operations 20%8.5/10
The four factors average 8.1 by weight, which rounds to 8/10.
Direct answer
Is Mercia Research legit?
Mercia Research is a registered UK supplier with nine authentic Janoshik COAs and an early independent customer-review record. We rate it 8/10. The reports give useful concentration, purity, metals and endotoxin evidence, while the Selank concentration, high NAD+ and SS-31 endotoxin measurements, and gaps in complete product reports deserve close attention.
COA evidenceCOA quality 8/10✓COA verified
Mercia publishes nine complete COAs from Janoshik Analytical, each paired with matching heavy-metals and endotoxin reports. All nine cover at least four test categories across identity, concentration, heavy metals and endotoxin; seven also report purity, ranging from 96.470% to 99.959%. The short, single-batch history and material concentration and endotoxin findings limit the score. For these reasons, we rate Mercia Research 8/10 for COA practices.
Trustpilot shows 4.2/5 from 11 reviews on November 12, 2026, with ten five-star reviews and one one-star review. Buyers repeatedly describe quick delivery, helpful communication and careful packaging. The one-star review reports a wrong product and weeks spent seeking a resolution through WhatsApp. Mercia replied asking for the order reference and offering priority investigation. The independent record is small and more mixed than the unqualified customer claims on the storefront. Read the independent reviews.
Every complete COA names Mercia Research Limited as client and manufacturer. The nine groups comprise 27 original Janoshik documents dated September 15–18, 2026. Arsenic, cadmium, lead and mercury were not detected in every linked metals panel. Endotoxin results range from <1 to 129.130 EU/mL. Janoshik prints numerical measurements without pass/fail labels or application-specific limits. Identity and concentration are distinct from chromatographic purity. The Ipamorelin/CJC and NAD+ main reports print no purity percentage.
03
Measured concentration and endotoxin findings
Selank measures 3.59 mg/mL. At the stated 3 mL cartridge volume, that is 10.77 mg, or 53.85% of the current 20 mg label, using the stated nominal volume. Tesamorelin has 96.470% purity, and Janoshik reports a gelled sample. SS-31 measures 129.130 EU/mL endotoxin and NAD+ measures 54.239 EU/mL. The other seven complete groups have <1–3.872 EU/mL. The original figures remain visible in each report.
04
Product and report coverage
The current catalog contains 13 single liquid pens. Nine have a complete same-compound COA, including three related-strength or sample-scope cases. MOTS-c is currently 20 mg while its report labels 30 mg. SS-31 is 25 mg while its report labels 30 mg. Mercia says the NAD+ concentration assay tested a 1000 mg vial of the same solution, while the report labels a 500 mg cartridge. These source differences stay with the relevant reports. BPC-157/TB-500, Semax, GLOW and KLOW have no complete same-product COA. Six unpaired contamination sheets cover BPC-157/TB-500, TB-500 and Semax. Reports on separate ingredients do not establish the composition of GLOW or KLOW. Browse Mercia’s source library.
05
Business identity and history
Companies House lists active Mercia Research Limited, company 17189709, incorporated on April 29, 2026. John-Paul Bartholomew Charles Kelly is its listed director. The registered office is 5th Floor, 167–169 Great Portland Street, London W1W 5PF, matching the website. The .com registry dates the domain to April 28, 2026. Mercia says orders ship from a UK fulfillment partner. The London address is a registered office. View the Companies House record.
06
Shipping, payment and returns
UK shipping costs £15 and becomes free at £300. Orders placed Monday to Thursday usually dispatch the next business day by Royal Mail Tracked 24. Friday-to-Sunday orders dispatch from Monday. Typical UK transit is 1–2 business days after dispatch. The checkout offers credit/debit cards, Apple Pay and bank transfer by invoice. Its destination selector covers the UK and EU countries. Temperature-sensitive goods normally cannot be returned after dispatch. Damaged, wrong or defective deliveries should be reported within 48 hours. Read shipping and return details.
Details
Payment methods
Credit/debit cards
Apple Pay
Bank transfer by invoice
Shipping
UK shipping costs £15 and becomes free at £300. Orders placed Monday to Thursday usually dispatch the next business day by Royal Mail Tracked 24; Friday-to-Sunday orders dispatch from Monday. Typical UK transit is 1–2 business days after dispatch. The checkout offers credit/debit cards, Apple Pay and bank transfer by invoice. Its destination selector covers the UK and EU countries. Temperature-sensitive goods normally cannot be returned after dispatch. Damaged, wrong or defective deliveries should be reported within 48 hours.
Ships to
UK and EU checkout destinations
Products (13)
Single liquid pens are priced in GBP. The package contains a 3 mL cartridge and pen.
Product
Price
Package
Status
BPC-157 / TB-500 20mg penFull COA not published
A complete identity/content COA is not published for this product.
MOTS-c 20mg pen5-test panelCOA on file Janoshik Analytical · Analysis date Sep 18, 2026 · Product reference
Related report — 30 mg label. The report labels a 30 mg cartridge. The current storefront labels 20 mg. At the stated 3 mL capacity, 6.86 mg/mL corresponds to 20.58 mg. This calculation uses nominal volume, not a laboratory measurement of total fill.
NAD+ 500mg pen4-test panelCOA on file Janoshik Analytical · Analysis date Sep 15, 2026 · Product reference
Related report — 500 mg label. Mercia states that the concentration assay used a 1000 mg vial of the same solution while the current product is 500 mg. The official report labels a 500 mg cartridge and measures 345.68 mg/mL. The source discrepancy remains unresolved.
SS-31 (Elamipretide) 25mg pen5-test panelCOA on file Janoshik Analytical · Analysis date Sep 18, 2026 · Product reference
Related report — 30 mg label. The report labels a 30 mg cartridge. The current storefront labels 25 mg. At nominal 3 mL, 8.61 mg/mL corresponds to 25.83 mg. Actual total fill was not measured.
Five cheapest in-stock package prices per compound across every tracked vendor — not just Mercia Research.
No in-stock compounds with a catalog match are available for market history.
Frequently asked questions
Is Mercia Research legit?
Mercia Research is a registered UK supplier with nine authentic Janoshik COAs and an early independent customer-review record. We rate it 8/10. The reports give useful concentration, purity, metals and endotoxin evidence, while the Selank concentration, high NAD+ and SS-31 endotoxin measurements, and gaps in complete product reports deserve close attention. Affiliate links never affect the score.
Does Mercia Research have a coupon code?
Code MR-V8YG9MQW gives customers 15% off your first order. Enter the code at checkout and confirm the discount.
Where does Mercia Research ship?
Mercia Research ships to UK and EU checkout destinations. UK shipping costs £15 and becomes free at £300. Orders placed Monday to Thursday usually dispatch the next business day by Royal Mail Tracked 24; Friday-to-Sunday orders dispatch from Monday. Typical UK transit is 1–2 business days after dispatch. The checkout offers credit/debit cards, Apple Pay and bank transfer by invoice. Its destination selector covers the UK and EU countries. Temperature-sensitive goods normally cannot be returned after dispatch. Damaged, wrong or defective deliveries should be reported within 48 hours.
Does Mercia Research publish COAs?
COA ✓. Open the vendor's certificate library and match each report to the exact product, strength, and lot before ordering.
What do customer reviews say about Mercia Research?
Trustpilot 4.2/5 from 11 reviews, checked November 12, 2026. Ten five-star reviews and one wrong-item complaint.
