What Happened to Peptide Sciences?

Peptide Sciences stopped selling on Friday, March 6, 2026. The storefront at peptidesciences.com was replaced by a short closure notice that day, and seven months later the notice is still all the site shows. Old product pages, the refund page and the account login all forward to it.

The store had been one of the most-searched names in US research peptides, with a domain that dates back to December 2009 and a catalog of 140 products two weeks before it closed. Within a day of the closure, someone registered a new domain built on its name.

When did Peptide Sciences shut down?

The last working week looked ordinary from the outside. The store’s own sitemap shows product records being edited every day from March 2 to March 6, and its product index on February 22 listed 135 of its 140 products as in stock. On March 6 the home page became the closure notice, and long-time buyers were trading the news by that afternoon.

The Wayback Machine’s last capture of the working home page is from January 3, 2026. The next one, on March 8, already shows the notice. Since then the wording has been expanded twice:

Why did Peptide Sciences shut down?

The company’s whole explanation is the notice itself: after careful consideration, it chose to “voluntarily shut down operations and discontinue the sale of its research products.” It named no cause. No FDA warning letter or federal charge naming Peptide Sciences has been made public, and the industry articles that blame a regulatory crackdown are describing the climate around the closure, not anything the company said.

What the store’s own records do show is that the shutdown came in two steps. The weight-loss compounds went first, months before the rest.

When did Peptide Sciences stop selling retatrutide and tirzepatide?

In the second half of 2025. The store’s product index on October 12, 2025 still listed four weight-loss compounds, all in stock:

By the next archived copy of the index, on December 21, 2025, all four were gone, and none came back before March. Researchers who bought their retatrutide or tirzepatide there had already lost that source about three months before the store closed.

Is Peptide Sciences coming back?

Nothing on its own site points that way. The notice says research product sales have ended, and its newest paragraphs are about protecting the name: Peptide Sciences keeps its brand, trademarks and goodwill and says it will enforce them. That keeps the name out of other hands. It is not a relaunch plan.

The site has been set up to stay closed: the page tells search engines not to index it, the store’s data connections refuse outside requests, and the domain is paid up through December 2029. In seven months the original site has announced no new store, no new name and no successor, and the notice calls anyone claiming to be one unauthorized.

Are the new Peptide Sciences websites real?

No. The closure notice says any website, platform or person claiming to be Peptide Sciences, a successor to it or a seller of its products “is unauthorized, fraudulent, and has no affiliation with our company.” Every site that took the name was registered in 2026, two of them before the closure:

Buyers who lost money describe the same sequence. The order goes through on a site that looks like the old store. Then a text message arrives from an unknown number, saying card processing is down and asking for the money to be sent outside the checkout, with no order page behind the request. After the money is sent, the messages stop. Reported losses run from $290 to $423, and at least one buyer paid on a friend’s recommendation without knowing the original store had closed.

Each one uses the old name with a word or a letter added or changed. The original domain, registered in 2009, shows nothing but the notice.

Moving your research from Peptide Sciences

Simms Research stocks 23 of the compounds and blends on Peptide Sciences’ final product index, plus retatrutide and tirzepatide, the two weight-loss compounds Peptide Sciences dropped in late 2025. Simms lists retatrutide at $84 and tirzepatide at $65 for 10mg, against the $230 for 12mg and $200 for 10mg Peptide Sciences charged in October 2025. For the rest, here are Peptide Sciences’ last listed prices beside Simms Research’s prices today:

Each Simms Research batch is published with its source certificate on the lab results page, which holds 52 tested batches. The newest BPC-157 batch, 2026-B670, came back at 99.651% purity by RP-HPLC on July 16, 2026. LC-MS confirmed its identity, three vials averaged 10.19mg against the 10mg label, and the endotoxin, heavy-metal and sterility screens passed; earlier batches sit on the same BPC-157 batch history. The Klow blend’s July 17 batch, 2026-KW189, measured 99.647% with 87.35mg in an 80mg vial (see the Klow record). The guide on how to read a peptide certificate of analysis explains what each of those fields means.

Orders placed before 5PM Eastern ship the same day, from the Florida office described on the About page, by UPS Standard or FedEx 2-Day, and FedEx 2-Day is free over $200. Every order carries a free Delivery Guarantee: a package lost in transit, stolen after a delivery scan or damaged on arrival is replaced at no charge, and a wrong or defective product reported within 48 hours is replaced or refunded. The details are in the shipping policy and the refund and return policy.

Checkout needs no account. The payment method is chosen at checkout, and the order page and order email show the total, who receives the payment and the order number. Simms Research takes no cryptocurrency.

What Peptide Sciences sold before it closed

The final archived product index, from February 22, 2026, lists 140 products in seven groups: injectable research peptides, peptide blends, capsules, IGF-1 proteins, melanotan peptides, bioregulators and topical cosmetic peptides. A large share sat outside the usual vial catalog, with 15 capsule products, 18 bioregulators and 21 topical cosmetic peptides sold in sizes from 200mg to a full gram.

Prices sat at the top of the market. BPC-157 was $59.50 for 5mg and $100 for 10mg. Full-length thymosin beta-4 was $165 for 10mg, the Klow blend $395 for 80mg, NAD+ $300 for 750mg and topical GHK-Cu $500 for a gram. Buying several of the same item took a few dollars off each one.

Orders paid after noon Pacific time shipped the next business day. The checkout pages mention Apple Pay and ACH e-checks, and the terms made e-checks payable to P-Sciences, Inc., the business behind the store.

Do Peptide Sciences promo codes still work?

No. A code needs a checkout, and peptidesciences.com no longer has one. The codes still circulating under the name belong to the copycat stores, like the 5% “peptidesciences” code on the site registered the day after the closure.

The original store’s own savings ran through customer accounts rather than public codes: a 10% credit for logging in or signing up at checkout, a $10 credit for a new account and $1 back for every $100 spent. Those balances lived inside accounts that can no longer be opened, because the login page forwards to the notice.

What happened to open orders and account credit?

The notice says nothing about orders that were paid but not yet shipped, refunds or unspent credit. Its only contact is the customer service address at peptidesciencesmail.com, offered for reporting impostor sites, and there is no longer an order page or account page to check status.

For buyers still holding Peptide Sciences vials, the product pages that described them went down with the store. A sealed vial can still be sent to an independent peptide lab for identity, purity and content testing.

Frequently asked questions

Who owned Peptide Sciences?

The store’s terms name P-Sciences, Inc. as the business behind it. Its footer gave a mailing address in Boca Raton, Florida, while the business details built into its pages listed Henderson, Nevada. No buyer, successor or new owner has been announced on the original site.

Why is the Peptide Sciences website down?

The site is up, but the store is gone. Every page now opens the closure notice, which is also set to stay out of search results.

Is Peptide Sciences still in business?

Not as a store. Sales ended on March 6, 2026, and the site now carries only the notice that holds on to the name and trademarks and disowns the copycat stores.

Did Peptide Sciences change its name?

No. The notice says the company keeps its name, and any site presenting itself as a renamed Peptide Sciences or a successor is, in the company’s own word, unauthorized.

Was Peptide Sciences a compounding pharmacy?

No. It sold research-use-only products. Its terms limited sales to buyers over 21 and described the products as intended for in-vitro laboratory research, not for human use.

Why are peptide companies being shut down?

Peptide Sciences says its closure was its own choice. Other 2026 cases involved government action: agents searched the North Sioux City, South Dakota, building listed for Apex Peptides on September 23 (covered in What Happened to Apex Peptides?), and the owner of Paradigm Peptides received a 70-month federal prison sentence on July 30.