Pürblack Shilajit Review: What Its Independent Lab Reports Show
Last reviewed October 2026 · 6 min read
The short answer
On the evidence we can check, Pürblack's resins are among the best-documented shilajit products we grade. All seven carry reports from Cambium Analytica, an ISO/IEC 17025 laboratory, that give numeric arsenic, cadmium, lead and mercury on the finished product, a microbial panel and a batch code, and all seven grade A+. Two things keep this from being a blanket endorsement: some of Pürblack's own documents give different numbers for the same batch, and a clean report does not show that any shilajit does what its marketing says.
Disclosure
ShilajitDB earns no money from Pürblack or any other brand. There are no affiliate links on this site, and every product is graded by the same published formula. This page describes the evidence; it is not a sponsored review.
What Pürblack sells
Every Pürblack product we track is a resin: Research Grade, Déjà Brew, Immunity Max with Coated Silver, True Gold 555 PPM and the three White Rabbit resins (Serene, Slim and Vive). Life Cykel sells a Pürblack-made resin under its own label, so we count it as the same brand when we apply the two-per-brand cap on our best resin list. The company states US manufacture on every product.
Price per gram on the listings we track runs from about $3.31 (the 30 gram True Gold resin) to $5.00 (the 15 gram White Rabbit resins). Research Grade and Déjà Brew sit at $3.67. That is a premium over many unpurified resins, which is what the cost of finished-product testing would suggest, but price alone shows nothing about quality.
What the independent reports show
The seven Pürblack reports we reviewed were issued by Cambium Analytica, an ISO/IEC 17025 accredited laboratory, and published on 19 March 2026. Each one is addressed to the brand as client, identifies the sample by name, and carries:
- numeric arsenic, cadmium, lead and mercury results on the finished product (Immunity Max's mercury is reported as below the limit of quantification);
- a microbial panel;
- a batch or lot code that can be matched to a retail jar.
Our grade is built from exactly those items (a named independent lab, numeric heavy metals on the finished product, a microbial panel, a batch code and a recent date), which is why all seven resins reach A+. See how the grade works and how to read a COA to check any report yourself. The per-product reports are on each Pürblack lab-tests page.
Where Pürblack's documents disagree
Earlier in 2026 we graded Pürblack on its own letterhead reports, which name no laboratory. When we found the Cambium reports we re-graded all seven upward. The two sets of documents do not always agree. For Déjà Brew, a Pürblack-letterhead PDF dated 21 May 2025 and the Cambium report share the same batch code, yet the lead result is 1.12 on one and 0.444 on the other, and arsenic is 0.15 on one and 0.347 on the other. Different sample portions, different methods or different dates could explain part of that. It is still a gap a buyer should know about, and we grade the independent report, not the brand's own.
Batch codes are also inconsistent in format: the Slim and Vive resins carry lot codes that differ only by a slash. We treat that as a formatting quirk, not a different lot, but it is another reason to match the code on your jar to the report.
What we can't verify
- Where the reports live. As of our last check in late September 2026, Pürblack's own site still linked its own letterhead PDFs rather than the Cambium reports, so a buyer starting from the product page may never see the independent ones. Our grade docks transparency for that on most of the products.
- Facility certification. We record the manufacturing facility as not GMP certified. GMP is not part of our grade, because brands' GMP claims were mostly unverifiable.
- Add-ons. Coated Silver and True Gold are extra ingredients. A clean heavy-metals panel says nothing about whether they add anything, and we found no human trial that supports a benefit from them.
- Effects. A lab report documents what is in the jar, not what it does. For what the human research does and does not show, see the clinical trials, explained.
How to buy it well
If you choose Pürblack, match the batch code on your jar to a report, prefer the Cambium document over the brand-letterhead one, and compare the cost per gram across sizes (the 30 gram jars are cheaper per gram). For alternatives with different trade-offs, see best shilajit resin, best third-party tested and the full graded comparison.