Science.bio Alternative — Pure U.S. Peptides

What happened to Science.bio

Science.bio has permanently closed. The only primary source we can point to is the notice the company itself still serves at science.bio, which reads in full:

"After careful consideration, Science.bio has made the decision to permanently close and discontinue the sale of research products. We are deeply grateful for your ongoing support and advocacy. We are humbled and wishing you the very best."

That notice carries no date and no stated reason. Reporting and community discussion placed the closure in January 2026, but because we cannot confirm a specific day or a cause from the company itself, this page does not assert either. We previously published a precise closure date here; it was not supported by the source and has been removed.

The same notice carries an explicit warning that we want to reproduce accurately, because it applies to pages like this one:

"Any website, entity, or individuals claiming to be Science.bio, a successor to Science.bio, or falsely claiming to sell our products are fraudulent, unauthorized, and have absolutely no affiliation with our company. Do not interact with them and report them to us immediately."

To be unambiguous: Pure U.S. Peptides is not Science.bio, is not a successor to Science.bio, has absolutely no affiliation with Science.bio, and does not sell Science.bio products. We are a separate supplier. This page exists because researchers search for where else to buy comparable research compounds — not to claim any part of that company's identity or inventory. The notice also publishes a customer support contact for anyone with an unresolved balance; use that rather than us.

What we will not claim about Science.bio

Science.bio is closed, and its catalog, pricing, and documentation practices are no longer published anywhere we can verify. That means we cannot honestly compare our prices, catalog size, or certificate practices against theirs, and we no longer try to. Any comparison table you find online claiming specific Science.bio compound counts, per-mg prices, or COA policies is working from memory or from a cached copy, not from a checkable source.

What we can tell you is what we do, which you can verify on this site today.

What Pure U.S. Peptide offers

We carry a deliberately tight research catalog — 53 listings covering 31 distinct compounds, with 10 of those listings being bundles or blends — focused on molecules with deeper published literature rather than a broad assortment. The trade-off is explicit: less breadth, more depth per compound — research summaries, mechanism-of-action writeups, and PubMed-linked citations. If you need a compound we do not stock, we are not the right supplier for it.

On the operational side, 37 of those 53 listings publish the lot-specific certificate of analysis on the product page itself — the specific batch, on the SKU page, rather than a general archive you have to search or an email request after you buy. The remaining 16 show a visible "pending upload" badge; we would rather show that than post a generic certificate in place of a lot-specific one. Orders ship same-day from a U.S. fulfillment warehouse. We accept card payments via PSiFi, Zelle, Venmo, and Cash App, so there is no crypto-only checkout.

Longevity and nootropic compounds we carry

These are the compounds in our own catalog most often sought by longevity and nootropic researchers. All are research-only molecules supplied at 99%+ HPLC purity. Check the individual product page for its certificate of analysis — most carry a lot-specific COA, and the ones still awaiting a certificate say so on the page. This is a description of our catalog, not a claim about what any other vendor stocked.

• MOTS-c — mitochondrial-derived peptide, central to longevity research. MOTS-c at Pure US Peptide.
• NAD+ — nicotinamide adenine dinucleotide, mitochondrial cofactor for longevity research. NAD+ at Pure US Peptide.
• BPC-157 — connective-tissue research workhorse. BPC-157 at Pure US Peptide.
• TB-500 — actin-binding research peptide. TB-500 at Pure US Peptide.
• Selank — selective nootropic research peptide. Selank at Pure US Peptide.
• Semax — nootropic research peptide. Semax at Pure US Peptide.
• Epitalon — telomere-related longevity research compound, listed in our catalog under the spelling Epithalon. Epithalon at Pure US Peptide.

Switching guide for former Science.bio customers

If you were a regular Science.bio customer, the migration path is straightforward:

1. Document your prior catalog. Make a list of the compounds you regularly ordered from Science.bio. The longevity research community typically anchors on three to five compounds — MOTS-c, NAD+, and one or two of BPC-157 / TB-500 / Selank / Semax.
2. Cross-reference our catalog. Compounds on our product list carry a mechanism-of-action writeup and PubMed citations, and most carry a lot-specific COA on the product page itself. Where a certificate is still pending, the page says so rather than showing a stand-in. Pull the COA and verify lot purity before you commit to a first order.
3. Run a small first-batch validation. Place a small order using code SBREFUGEE25 (20% off the first order) to validate purity and shipping speed against your previous baseline before committing to a larger order.
4. Treat any "Science.bio is back" site as suspect. Their own closure notice states that any website or entity claiming to be Science.bio or a successor to it is fraudulent and unauthorized, and asks that you report it to them. Read the notice yourself at science.bio, and see our companion explainer at /what-happened-to-science-bio.