Analytical methods

Certificate of analysis

Every catalog lot is released against a written specification. A signed certificate of analysis accompanies each shipment and records the values below for that exact lot number.

Purity	RP-HPLC, UV 214 nm · ≥99.0% single peak
Identity	ESI-MS, observed vs. theoretical mass
Endotoxin	LAL kinetic chromogenic · <0.05 EU/mg
Water content	Karl Fischer titration
Appearance	White to off-white lyophilized cake
Counter-ion	Acetate unless otherwise stated

Research use only · not for human or veterinary consumption

Verified orders

What researchers say

4.8 / 5 average

“Third order from Nucleus and every vial arrived cold-packed with the COA matching the lot number on the label. Weighing on my milligram scale, amounts have been spot on.”

Marcus T.Retatrutide · September 2026

“What sold me was being able to open the Janoshik report right on the product page before buying. Shipping was two days and the vials were sealed properly.”

Dana R.BPC-157 · September 2026

“Clean site, honest lab data, no hype claims. Would like more bundle options, but the peptides themselves test exactly as listed.”

Kwame O.TB-500 · August 2026

“Recommended. Fast shipping, and delivery times were fully in line with the estimated window. Packaging was solid — even with a less-than-careful courier, everything arrived intact with no damage. On top of that, the COA certificates and test results were included. Fully recommended.”

Verified buyerPeptide order · October 2026

“TOP!! Everything 5+ The delivery arrived as agreed, was well packaged, and everything was in perfect condition. Shipping was very fast, and communication was always prompt and reliable.”

Verified buyerPeptide order · October 2026

“First order, will order again. Just had my first order and can't complain. Delivery was fast. They have certificates for selected products. So far so good.”

Verified buyerPeptide order · October 2026