Every bottle we sell has a paper trail. Here's exactly how Selenewell products are made, tested, and verified — and how you can check for yourself.
How our products are made
- Manufactured in the USA in FDA-registered facilities, with domestic and globally sourced ingredients.
- cGMP-compliant — current Good Manufacturing Practices, the FDA's quality standard for dietary supplements, covering identity, purity, strength, and composition.
- Shipped from US warehouses — your order never crosses an ocean.
Testing and certificates
We publish what we hold, and we are specific about what each document covers. These are manufacturer certificates for a representative batch — not the batch in your bottle:
- Magnesium Glycinate — batch MGL250923 (PDF): heavy metals by ICP-MS and elemental magnesium.
- Probiotic 40 Billion — batch PB250812 (PDF): heavy metals by ICP-MS and microbiological safety. It does not include a CFU potency assay, which is why the 40 billion figure is described on the product page as a formulation specification rather than a measured result.
- Lion’s Mane Mushroom — lot 2023-13956 (PDF): polysaccharides by UV-VIS, reported at 401.78 mg against the 400 mg on the label, plus appearance, weight and disintegration. This is the only lot we hold with an assay of the active, and its shelf life ends in August 2026, so we say so rather than let it read as current.
- Lion’s Mane Mushroom — lot B24H001 (PDF): heavy metals by ICP-MS with results, not limits — lead at 0.22 mcg per serving against a specification of 2.75 — and microbiological safety. It does not assay the polysaccharides, which is why we publish both documents rather than one.
- Resveratrol — lot RVT250409 (PDF): resveratrol at 50.12% by HPLC against a specification of not less than 50%, and heavy metals by ICP-MS — arsenic, cadmium, lead and mercury all below the limit of quantification.
For Creatine Hydration Powder what we currently hold is a manufacturer specification sheet, not a certificate of analysis — its values are limits rather than results — so we do not publish it as one and do not claim the product has been batch tested. We have requested a real certificate.
Our three bundles — Strong & Rested, The Full Rhythm and The Complete Ritual — are the same bottles listed above, boxed together. There is no separate document for a bundle: what we hold for one is what we hold for each product inside it, exactly as set out on this page.
Request the certificate of analysis — tell us the product and, if you have already ordered, your order number. We reply within 1–2 business days. You do not have to take our word for any of this, which is the point of publishing it.
Full-dose transparency
Every Selenewell label lists every active ingredient and its exact dose. If an ingredient is in the bottle, it's on the label — no "proprietary blends" that hide how much of anything you're getting.
One honest exception, and we would rather tell you than have you find it. Our Probiotic 40 Billion lists its four bacterial strains inside a blend, which is how essentially every probiotic on the market is labelled: live-organism counts are measured for the blend, not split per strain. What we do instead is name each strain down to its strain code — Lactobacillus acidophilus La-14, Bifidobacterium lactis Bl-04, Lactobacillus plantarum Lp-115 and Lactobacillus paracasei Lpc-37 — and print the formulated total, 40 billion CFU per serving at time of manufacture, along with the blend weight. Strain codes matter: research is run on specific strains, not on species, so naming them is what makes a probiotic checkable at all.
What supplements can and can't do
We're direct about this: dietary supplements support normal body functions — sleep, strength, balance, digestion. They are not medicines, and no supplement can diagnose, treat, cure, or prevent any disease. If you have a medical condition, are pregnant or nursing, or take medication, talk with your healthcare professional before starting any supplement. Read our full medical disclaimer.
Our guarantee
The first bottle is on us if it isn't right. If your first Selenewell order doesn't suit you, tell us within 60 days of delivery and we refund it — and in almost every case we won't ask you to ship anything back. That applies once per customer and covers your entire first order, whether that is one product, several, or a bundle.
Unopened products can be refunded in full within 60 days of delivery, with nothing to ship back in almost every case. Anything that arrives damaged, defective, incorrect or never arrives at all, we replace or refund in full, shipping included, with nothing to send back. The details are in our refund policy.